Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / media / dvb-frontends / mb86a20s.c
diff --git a/kernel/drivers/media/dvb-frontends/mb86a20s.c b/kernel/drivers/media/dvb-frontends/mb86a20s.c
new file mode 100644 (file)
index 0000000..8f54c39
--- /dev/null
@@ -0,0 +1,2147 @@
+/*
+ *   Fujitu mb86a20s ISDB-T/ISDB-Tsb Module driver
+ *
+ *   Copyright (C) 2010-2013 Mauro Carvalho Chehab
+ *   Copyright (C) 2009-2010 Douglas Landgraf <dougsland@redhat.com>
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License as
+ *   published by the Free Software Foundation version 2.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *   General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <asm/div64.h>
+
+#include "dvb_frontend.h"
+#include "mb86a20s.h"
+
+#define NUM_LAYERS 3
+
+enum mb86a20s_bandwidth {
+       MB86A20S_13SEG = 0,
+       MB86A20S_13SEG_PARTIAL = 1,
+       MB86A20S_1SEG = 2,
+       MB86A20S_3SEG = 3,
+};
+
+static u8 mb86a20s_subchannel[] = {
+       0xb0, 0xc0, 0xd0, 0xe0,
+       0xf0, 0x00, 0x10, 0x20,
+};
+
+struct mb86a20s_state {
+       struct i2c_adapter *i2c;
+       const struct mb86a20s_config *config;
+       u32 last_frequency;
+
+       struct dvb_frontend frontend;
+
+       u32 if_freq;
+       enum mb86a20s_bandwidth bw;
+       bool inversion;
+       u32 subchannel;
+
+       u32 estimated_rate[NUM_LAYERS];
+       unsigned long get_strength_time;
+
+       bool need_init;
+};
+
+struct regdata {
+       u8 reg;
+       u8 data;
+};
+
+#define BER_SAMPLING_RATE      1       /* Seconds */
+
+/*
+ * Initialization sequence: Use whatevere default values that PV SBTVD
+ * does on its initialisation, obtained via USB snoop
+ */
+static struct regdata mb86a20s_init1[] = {
+       { 0x70, 0x0f },
+       { 0x70, 0xff },
+       { 0x08, 0x01 },
+       { 0x50, 0xd1 }, { 0x51, 0x20 },
+};
+
+static struct regdata mb86a20s_init2[] = {
+       { 0x28, 0x22 }, { 0x29, 0x00 }, { 0x2a, 0x1f }, { 0x2b, 0xf0 },
+       { 0x3b, 0x21 },
+       { 0x3c, 0x38 },
+       { 0x01, 0x0d },
+       { 0x04, 0x08 }, { 0x05, 0x03 },
+       { 0x04, 0x0e }, { 0x05, 0x00 },
+       { 0x04, 0x0f }, { 0x05, 0x37 },
+       { 0x04, 0x0b }, { 0x05, 0x78 },
+       { 0x04, 0x00 }, { 0x05, 0x00 },
+       { 0x04, 0x01 }, { 0x05, 0x1e },
+       { 0x04, 0x02 }, { 0x05, 0x07 },
+       { 0x04, 0x03 }, { 0x05, 0xd0 },
+       { 0x04, 0x09 }, { 0x05, 0x00 },
+       { 0x04, 0x0a }, { 0x05, 0xff },
+       { 0x04, 0x27 }, { 0x05, 0x00 },
+       { 0x04, 0x28 }, { 0x05, 0x00 },
+       { 0x04, 0x1e }, { 0x05, 0x00 },
+       { 0x04, 0x29 }, { 0x05, 0x64 },
+       { 0x04, 0x32 }, { 0x05, 0x02 },
+       { 0x04, 0x14 }, { 0x05, 0x02 },
+       { 0x04, 0x04 }, { 0x05, 0x00 },
+       { 0x04, 0x05 }, { 0x05, 0x22 },
+       { 0x04, 0x06 }, { 0x05, 0x0e },
+       { 0x04, 0x07 }, { 0x05, 0xd8 },
+       { 0x04, 0x12 }, { 0x05, 0x00 },
+       { 0x04, 0x13 }, { 0x05, 0xff },
+       { 0x04, 0x15 }, { 0x05, 0x4e },
+       { 0x04, 0x16 }, { 0x05, 0x20 },
+
+       /*
+        * On this demod, when the bit count reaches the count below,
+        * it collects the bit error count. The bit counters are initialized
+        * to 65535 here. This warrants that all of them will be quickly
+        * calculated when device gets locked. As TMCC is parsed, the values
+        * will be adjusted later in the driver's code.
+        */
+       { 0x52, 0x01 },                         /* Turn on BER before Viterbi */
+       { 0x50, 0xa7 }, { 0x51, 0x00 },
+       { 0x50, 0xa8 }, { 0x51, 0xff },
+       { 0x50, 0xa9 }, { 0x51, 0xff },
+       { 0x50, 0xaa }, { 0x51, 0x00 },
+       { 0x50, 0xab }, { 0x51, 0xff },
+       { 0x50, 0xac }, { 0x51, 0xff },
+       { 0x50, 0xad }, { 0x51, 0x00 },
+       { 0x50, 0xae }, { 0x51, 0xff },
+       { 0x50, 0xaf }, { 0x51, 0xff },
+
+       /*
+        * On this demod, post BER counts blocks. When the count reaches the
+        * value below, it collects the block error count. The block counters
+        * are initialized to 127 here. This warrants that all of them will be
+        * quickly calculated when device gets locked. As TMCC is parsed, the
+        * values will be adjusted later in the driver's code.
+        */
+       { 0x5e, 0x07 },                         /* Turn on BER after Viterbi */
+       { 0x50, 0xdc }, { 0x51, 0x00 },
+       { 0x50, 0xdd }, { 0x51, 0x7f },
+       { 0x50, 0xde }, { 0x51, 0x00 },
+       { 0x50, 0xdf }, { 0x51, 0x7f },
+       { 0x50, 0xe0 }, { 0x51, 0x00 },
+       { 0x50, 0xe1 }, { 0x51, 0x7f },
+
+       /*
+        * On this demod, when the block count reaches the count below,
+        * it collects the block error count. The block counters are initialized
+        * to 127 here. This warrants that all of them will be quickly
+        * calculated when device gets locked. As TMCC is parsed, the values
+        * will be adjusted later in the driver's code.
+        */
+       { 0x50, 0xb0 }, { 0x51, 0x07 },         /* Enable PER */
+       { 0x50, 0xb2 }, { 0x51, 0x00 },
+       { 0x50, 0xb3 }, { 0x51, 0x7f },
+       { 0x50, 0xb4 }, { 0x51, 0x00 },
+       { 0x50, 0xb5 }, { 0x51, 0x7f },
+       { 0x50, 0xb6 }, { 0x51, 0x00 },
+       { 0x50, 0xb7 }, { 0x51, 0x7f },
+
+       { 0x50, 0x50 }, { 0x51, 0x02 },         /* MER manual mode */
+       { 0x50, 0x51 }, { 0x51, 0x04 },         /* MER symbol 4 */
+       { 0x45, 0x04 },                         /* CN symbol 4 */
+       { 0x48, 0x04 },                         /* CN manual mode */
+
+       { 0x50, 0xd6 }, { 0x51, 0x1f },
+       { 0x50, 0xd2 }, { 0x51, 0x03 },
+       { 0x50, 0xd7 }, { 0x51, 0xbf },
+       { 0x28, 0x74 }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0xff },
+       { 0x28, 0x46 }, { 0x29, 0x00 }, { 0x2a, 0x1a }, { 0x2b, 0x0c },
+
+       { 0x04, 0x40 }, { 0x05, 0x00 },
+       { 0x28, 0x00 }, { 0x2b, 0x08 },
+       { 0x28, 0x05 }, { 0x2b, 0x00 },
+       { 0x1c, 0x01 },
+       { 0x28, 0x06 }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x1f },
+       { 0x28, 0x07 }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x18 },
+       { 0x28, 0x08 }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x12 },
+       { 0x28, 0x09 }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x30 },
+       { 0x28, 0x0a }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x37 },
+       { 0x28, 0x0b }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x02 },
+       { 0x28, 0x0c }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x09 },
+       { 0x28, 0x0d }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x06 },
+       { 0x28, 0x0e }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x7b },
+       { 0x28, 0x0f }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x76 },
+       { 0x28, 0x10 }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x7d },
+       { 0x28, 0x11 }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x08 },
+       { 0x28, 0x12 }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x0b },
+       { 0x28, 0x13 }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x00 },
+       { 0x28, 0x14 }, { 0x29, 0x00 }, { 0x2a, 0x01 }, { 0x2b, 0xf2 },
+       { 0x28, 0x15 }, { 0x29, 0x00 }, { 0x2a, 0x01 }, { 0x2b, 0xf3 },
+       { 0x28, 0x16 }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x05 },
+       { 0x28, 0x17 }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x16 },
+       { 0x28, 0x18 }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x0f },
+       { 0x28, 0x19 }, { 0x29, 0x00 }, { 0x2a, 0x07 }, { 0x2b, 0xef },
+       { 0x28, 0x1a }, { 0x29, 0x00 }, { 0x2a, 0x07 }, { 0x2b, 0xd8 },
+       { 0x28, 0x1b }, { 0x29, 0x00 }, { 0x2a, 0x07 }, { 0x2b, 0xf1 },
+       { 0x28, 0x1c }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x3d },
+       { 0x28, 0x1d }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x94 },
+       { 0x28, 0x1e }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0xba },
+       { 0x50, 0x1e }, { 0x51, 0x5d },
+       { 0x50, 0x22 }, { 0x51, 0x00 },
+       { 0x50, 0x23 }, { 0x51, 0xc8 },
+       { 0x50, 0x24 }, { 0x51, 0x00 },
+       { 0x50, 0x25 }, { 0x51, 0xf0 },
+       { 0x50, 0x26 }, { 0x51, 0x00 },
+       { 0x50, 0x27 }, { 0x51, 0xc3 },
+       { 0x50, 0x39 }, { 0x51, 0x02 },
+       { 0xec, 0x0f },
+       { 0xeb, 0x1f },
+       { 0x28, 0x6a }, { 0x29, 0x00 }, { 0x2a, 0x00 }, { 0x2b, 0x00 },
+       { 0xd0, 0x00 },
+};
+
+static struct regdata mb86a20s_reset_reception[] = {
+       { 0x70, 0xf0 },
+       { 0x70, 0xff },
+       { 0x08, 0x01 },
+       { 0x08, 0x00 },
+};
+
+static struct regdata mb86a20s_per_ber_reset[] = {
+       { 0x53, 0x00 }, /* pre BER Counter reset */
+       { 0x53, 0x07 },
+
+       { 0x5f, 0x00 }, /* post BER Counter reset */
+       { 0x5f, 0x07 },
+
+       { 0x50, 0xb1 }, /* PER Counter reset */
+       { 0x51, 0x07 },
+       { 0x51, 0x00 },
+};
+
+/*
+ * I2C read/write functions and macros
+ */
+
+static int mb86a20s_i2c_writereg(struct mb86a20s_state *state,
+                            u8 i2c_addr, u8 reg, u8 data)
+{
+       u8 buf[] = { reg, data };
+       struct i2c_msg msg = {
+               .addr = i2c_addr, .flags = 0, .buf = buf, .len = 2
+       };
+       int rc;
+
+       rc = i2c_transfer(state->i2c, &msg, 1);
+       if (rc != 1) {
+               dev_err(&state->i2c->dev,
+                       "%s: writereg error (rc == %i, reg == 0x%02x, data == 0x%02x)\n",
+                       __func__, rc, reg, data);
+               return rc;
+       }
+
+       return 0;
+}
+
+static int mb86a20s_i2c_writeregdata(struct mb86a20s_state *state,
+                                    u8 i2c_addr, struct regdata *rd, int size)
+{
+       int i, rc;
+
+       for (i = 0; i < size; i++) {
+               rc = mb86a20s_i2c_writereg(state, i2c_addr, rd[i].reg,
+                                          rd[i].data);
+               if (rc < 0)
+                       return rc;
+       }
+       return 0;
+}
+
+static int mb86a20s_i2c_readreg(struct mb86a20s_state *state,
+                               u8 i2c_addr, u8 reg)
+{
+       u8 val;
+       int rc;
+       struct i2c_msg msg[] = {
+               { .addr = i2c_addr, .flags = 0, .buf = &reg, .len = 1 },
+               { .addr = i2c_addr, .flags = I2C_M_RD, .buf = &val, .len = 1 }
+       };
+
+       rc = i2c_transfer(state->i2c, msg, 2);
+
+       if (rc != 2) {
+               dev_err(&state->i2c->dev, "%s: reg=0x%x (error=%d)\n",
+                       __func__, reg, rc);
+               return (rc < 0) ? rc : -EIO;
+       }
+
+       return val;
+}
+
+#define mb86a20s_readreg(state, reg) \
+       mb86a20s_i2c_readreg(state, state->config->demod_address, reg)
+#define mb86a20s_writereg(state, reg, val) \
+       mb86a20s_i2c_writereg(state, state->config->demod_address, reg, val)
+#define mb86a20s_writeregdata(state, regdata) \
+       mb86a20s_i2c_writeregdata(state, state->config->demod_address, \
+       regdata, ARRAY_SIZE(regdata))
+
+/*
+ * Ancillary internal routines (likely compiled inlined)
+ *
+ * The functions below assume that gateway lock has already obtained
+ */
+
+static int mb86a20s_read_status(struct dvb_frontend *fe, fe_status_t *status)
+{
+       struct mb86a20s_state *state = fe->demodulator_priv;
+       int val;
+
+       *status = 0;
+
+       val = mb86a20s_readreg(state, 0x0a) & 0xf;
+       if (val < 0)
+               return val;
+
+       if (val >= 2)
+               *status |= FE_HAS_SIGNAL;
+
+       if (val >= 4)
+               *status |= FE_HAS_CARRIER;
+
+       if (val >= 5)
+               *status |= FE_HAS_VITERBI;
+
+       if (val >= 7)
+               *status |= FE_HAS_SYNC;
+
+       if (val >= 8)                           /* Maybe 9? */
+               *status |= FE_HAS_LOCK;
+
+       dev_dbg(&state->i2c->dev, "%s: Status = 0x%02x (state = %d)\n",
+                __func__, *status, val);
+
+       return val;
+}
+
+static int mb86a20s_read_signal_strength(struct dvb_frontend *fe)
+{
+       struct mb86a20s_state *state = fe->demodulator_priv;
+       struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+       int rc;
+       unsigned rf_max, rf_min, rf;
+
+       if (state->get_strength_time &&
+          (!time_after(jiffies, state->get_strength_time)))
+               return c->strength.stat[0].uvalue;
+
+       /* Reset its value if an error happen */
+       c->strength.stat[0].uvalue = 0;
+
+       /* Does a binary search to get RF strength */
+       rf_max = 0xfff;
+       rf_min = 0;
+       do {
+               rf = (rf_max + rf_min) / 2;
+               rc = mb86a20s_writereg(state, 0x04, 0x1f);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x05, rf >> 8);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x04, 0x20);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x05, rf);
+               if (rc < 0)
+                       return rc;
+
+               rc = mb86a20s_readreg(state, 0x02);
+               if (rc < 0)
+                       return rc;
+               if (rc & 0x08)
+                       rf_min = (rf_max + rf_min) / 2;
+               else
+                       rf_max = (rf_max + rf_min) / 2;
+               if (rf_max - rf_min < 4) {
+                       rf = (rf_max + rf_min) / 2;
+
+                       /* Rescale it from 2^12 (4096) to 2^16 */
+                       rf = rf << (16 - 12);
+                       if (rf)
+                               rf |= (1 << 12) - 1;
+
+                       dev_dbg(&state->i2c->dev,
+                               "%s: signal strength = %d (%d < RF=%d < %d)\n",
+                               __func__, rf, rf_min, rf >> 4, rf_max);
+                       c->strength.stat[0].uvalue = rf;
+                       state->get_strength_time = jiffies +
+                                                  msecs_to_jiffies(1000);
+                       return 0;
+               }
+       } while (1);
+}
+
+static int mb86a20s_get_modulation(struct mb86a20s_state *state,
+                                  unsigned layer)
+{
+       int rc;
+       static unsigned char reg[] = {
+               [0] = 0x86,     /* Layer A */
+               [1] = 0x8a,     /* Layer B */
+               [2] = 0x8e,     /* Layer C */
+       };
+
+       if (layer >= ARRAY_SIZE(reg))
+               return -EINVAL;
+       rc = mb86a20s_writereg(state, 0x6d, reg[layer]);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_readreg(state, 0x6e);
+       if (rc < 0)
+               return rc;
+       switch ((rc >> 4) & 0x07) {
+       case 0:
+               return DQPSK;
+       case 1:
+               return QPSK;
+       case 2:
+               return QAM_16;
+       case 3:
+               return QAM_64;
+       default:
+               return QAM_AUTO;
+       }
+}
+
+static int mb86a20s_get_fec(struct mb86a20s_state *state,
+                           unsigned layer)
+{
+       int rc;
+
+       static unsigned char reg[] = {
+               [0] = 0x87,     /* Layer A */
+               [1] = 0x8b,     /* Layer B */
+               [2] = 0x8f,     /* Layer C */
+       };
+
+       if (layer >= ARRAY_SIZE(reg))
+               return -EINVAL;
+       rc = mb86a20s_writereg(state, 0x6d, reg[layer]);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_readreg(state, 0x6e);
+       if (rc < 0)
+               return rc;
+       switch ((rc >> 4) & 0x07) {
+       case 0:
+               return FEC_1_2;
+       case 1:
+               return FEC_2_3;
+       case 2:
+               return FEC_3_4;
+       case 3:
+               return FEC_5_6;
+       case 4:
+               return FEC_7_8;
+       default:
+               return FEC_AUTO;
+       }
+}
+
+static int mb86a20s_get_interleaving(struct mb86a20s_state *state,
+                                    unsigned layer)
+{
+       int rc;
+       int interleaving[] = {
+               0, 1, 2, 4, 8
+       };
+
+       static unsigned char reg[] = {
+               [0] = 0x88,     /* Layer A */
+               [1] = 0x8c,     /* Layer B */
+               [2] = 0x90,     /* Layer C */
+       };
+
+       if (layer >= ARRAY_SIZE(reg))
+               return -EINVAL;
+       rc = mb86a20s_writereg(state, 0x6d, reg[layer]);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_readreg(state, 0x6e);
+       if (rc < 0)
+               return rc;
+
+       return interleaving[(rc >> 4) & 0x07];
+}
+
+static int mb86a20s_get_segment_count(struct mb86a20s_state *state,
+                                     unsigned layer)
+{
+       int rc, count;
+       static unsigned char reg[] = {
+               [0] = 0x89,     /* Layer A */
+               [1] = 0x8d,     /* Layer B */
+               [2] = 0x91,     /* Layer C */
+       };
+
+       dev_dbg(&state->i2c->dev, "%s called.\n", __func__);
+
+       if (layer >= ARRAY_SIZE(reg))
+               return -EINVAL;
+
+       rc = mb86a20s_writereg(state, 0x6d, reg[layer]);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_readreg(state, 0x6e);
+       if (rc < 0)
+               return rc;
+       count = (rc >> 4) & 0x0f;
+
+       dev_dbg(&state->i2c->dev, "%s: segments: %d.\n", __func__, count);
+
+       return count;
+}
+
+static void mb86a20s_reset_frontend_cache(struct dvb_frontend *fe)
+{
+       struct mb86a20s_state *state = fe->demodulator_priv;
+       struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+
+       dev_dbg(&state->i2c->dev, "%s called.\n", __func__);
+
+       /* Fixed parameters */
+       c->delivery_system = SYS_ISDBT;
+       c->bandwidth_hz = 6000000;
+
+       /* Initialize values that will be later autodetected */
+       c->isdbt_layer_enabled = 0;
+       c->transmission_mode = TRANSMISSION_MODE_AUTO;
+       c->guard_interval = GUARD_INTERVAL_AUTO;
+       c->isdbt_sb_mode = 0;
+       c->isdbt_sb_segment_count = 0;
+}
+
+/*
+ * Estimates the bit rate using the per-segment bit rate given by
+ * ABNT/NBR 15601 spec (table 4).
+ */
+static u32 isdbt_rate[3][5][4] = {
+       {       /* DQPSK/QPSK */
+               {  280850,  312060,  330420,  340430 }, /* 1/2 */
+               {  374470,  416080,  440560,  453910 }, /* 2/3 */
+               {  421280,  468090,  495630,  510650 }, /* 3/4 */
+               {  468090,  520100,  550700,  567390 }, /* 5/6 */
+               {  491500,  546110,  578230,  595760 }, /* 7/8 */
+       }, {    /* QAM16 */
+               {  561710,  624130,  660840,  680870 }, /* 1/2 */
+               {  748950,  832170,  881120,  907820 }, /* 2/3 */
+               {  842570,  936190,  991260, 1021300 }, /* 3/4 */
+               {  936190, 1040210, 1101400, 1134780 }, /* 5/6 */
+               {  983000, 1092220, 1156470, 1191520 }, /* 7/8 */
+       }, {    /* QAM64 */
+               {  842570,  936190,  991260, 1021300 }, /* 1/2 */
+               { 1123430, 1248260, 1321680, 1361740 }, /* 2/3 */
+               { 1263860, 1404290, 1486900, 1531950 }, /* 3/4 */
+               { 1404290, 1560320, 1652110, 1702170 }, /* 5/6 */
+               { 1474500, 1638340, 1734710, 1787280 }, /* 7/8 */
+       }
+};
+
+static void mb86a20s_layer_bitrate(struct dvb_frontend *fe, u32 layer,
+                                  u32 modulation, u32 forward_error_correction,
+                                  u32 guard_interval,
+                                  u32 segment)
+{
+       struct mb86a20s_state *state = fe->demodulator_priv;
+       u32 rate;
+       int mod, fec, guard;
+
+       /*
+        * If modulation/fec/guard is not detected, the default is
+        * to consider the lowest bit rate, to avoid taking too long time
+        * to get BER.
+        */
+       switch (modulation) {
+       case DQPSK:
+       case QPSK:
+       default:
+               mod = 0;
+               break;
+       case QAM_16:
+               mod = 1;
+               break;
+       case QAM_64:
+               mod = 2;
+               break;
+       }
+
+       switch (forward_error_correction) {
+       default:
+       case FEC_1_2:
+       case FEC_AUTO:
+               fec = 0;
+               break;
+       case FEC_2_3:
+               fec = 1;
+               break;
+       case FEC_3_4:
+               fec = 2;
+               break;
+       case FEC_5_6:
+               fec = 3;
+               break;
+       case FEC_7_8:
+               fec = 4;
+               break;
+       }
+
+       switch (guard_interval) {
+       default:
+       case GUARD_INTERVAL_1_4:
+               guard = 0;
+               break;
+       case GUARD_INTERVAL_1_8:
+               guard = 1;
+               break;
+       case GUARD_INTERVAL_1_16:
+               guard = 2;
+               break;
+       case GUARD_INTERVAL_1_32:
+               guard = 3;
+               break;
+       }
+
+       /* Samples BER at BER_SAMPLING_RATE seconds */
+       rate = isdbt_rate[mod][fec][guard] * segment * BER_SAMPLING_RATE;
+
+       /* Avoids sampling too quickly or to overflow the register */
+       if (rate < 256)
+               rate = 256;
+       else if (rate > (1 << 24) - 1)
+               rate = (1 << 24) - 1;
+
+       dev_dbg(&state->i2c->dev,
+               "%s: layer %c bitrate: %d kbps; counter = %d (0x%06x)\n",
+               __func__, 'A' + layer,
+               segment * isdbt_rate[mod][fec][guard]/1000,
+               rate, rate);
+
+       state->estimated_rate[layer] = rate;
+}
+
+static int mb86a20s_get_frontend(struct dvb_frontend *fe)
+{
+       struct mb86a20s_state *state = fe->demodulator_priv;
+       struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+       int layer, rc;
+
+       dev_dbg(&state->i2c->dev, "%s called.\n", __func__);
+
+       /* Reset frontend cache to default values */
+       mb86a20s_reset_frontend_cache(fe);
+
+       /* Check for partial reception */
+       rc = mb86a20s_writereg(state, 0x6d, 0x85);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_readreg(state, 0x6e);
+       if (rc < 0)
+               return rc;
+       c->isdbt_partial_reception = (rc & 0x10) ? 1 : 0;
+
+       /* Get per-layer data */
+
+       for (layer = 0; layer < NUM_LAYERS; layer++) {
+               dev_dbg(&state->i2c->dev, "%s: getting data for layer %c.\n",
+                       __func__, 'A' + layer);
+
+               rc = mb86a20s_get_segment_count(state, layer);
+               if (rc < 0)
+                       goto noperlayer_error;
+               if (rc >= 0 && rc < 14) {
+                       c->layer[layer].segment_count = rc;
+               } else {
+                       c->layer[layer].segment_count = 0;
+                       state->estimated_rate[layer] = 0;
+                       continue;
+               }
+               c->isdbt_layer_enabled |= 1 << layer;
+               rc = mb86a20s_get_modulation(state, layer);
+               if (rc < 0)
+                       goto noperlayer_error;
+               dev_dbg(&state->i2c->dev, "%s: modulation %d.\n",
+                       __func__, rc);
+               c->layer[layer].modulation = rc;
+               rc = mb86a20s_get_fec(state, layer);
+               if (rc < 0)
+                       goto noperlayer_error;
+               dev_dbg(&state->i2c->dev, "%s: FEC %d.\n",
+                       __func__, rc);
+               c->layer[layer].fec = rc;
+               rc = mb86a20s_get_interleaving(state, layer);
+               if (rc < 0)
+                       goto noperlayer_error;
+               dev_dbg(&state->i2c->dev, "%s: interleaving %d.\n",
+                       __func__, rc);
+               c->layer[layer].interleaving = rc;
+               mb86a20s_layer_bitrate(fe, layer, c->layer[layer].modulation,
+                                      c->layer[layer].fec,
+                                      c->guard_interval,
+                                      c->layer[layer].segment_count);
+       }
+
+       rc = mb86a20s_writereg(state, 0x6d, 0x84);
+       if (rc < 0)
+               return rc;
+       if ((rc & 0x60) == 0x20) {
+               c->isdbt_sb_mode = 1;
+               /* At least, one segment should exist */
+               if (!c->isdbt_sb_segment_count)
+                       c->isdbt_sb_segment_count = 1;
+       }
+
+       /* Get transmission mode and guard interval */
+       rc = mb86a20s_readreg(state, 0x07);
+       if (rc < 0)
+               return rc;
+       c->transmission_mode = TRANSMISSION_MODE_AUTO;
+       if ((rc & 0x60) == 0x20) {
+               /* Only modes 2 and 3 are supported */
+               switch ((rc >> 2) & 0x03) {
+               case 1:
+                       c->transmission_mode = TRANSMISSION_MODE_4K;
+                       break;
+               case 2:
+                       c->transmission_mode = TRANSMISSION_MODE_8K;
+                       break;
+               }
+       }
+       c->guard_interval = GUARD_INTERVAL_AUTO;
+       if (!(rc & 0x10)) {
+               /* Guard interval 1/32 is not supported */
+               switch (rc & 0x3) {
+               case 0:
+                       c->guard_interval = GUARD_INTERVAL_1_4;
+                       break;
+               case 1:
+                       c->guard_interval = GUARD_INTERVAL_1_8;
+                       break;
+               case 2:
+                       c->guard_interval = GUARD_INTERVAL_1_16;
+                       break;
+               }
+       }
+       return 0;
+
+noperlayer_error:
+
+       /* per-layer info is incomplete; discard all per-layer */
+       c->isdbt_layer_enabled = 0;
+
+       return rc;
+}
+
+static int mb86a20s_reset_counters(struct dvb_frontend *fe)
+{
+       struct mb86a20s_state *state = fe->demodulator_priv;
+       struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+       int rc, val;
+
+       dev_dbg(&state->i2c->dev, "%s called.\n", __func__);
+
+       /* Reset the counters, if the channel changed */
+       if (state->last_frequency != c->frequency) {
+               memset(&c->cnr, 0, sizeof(c->cnr));
+               memset(&c->pre_bit_error, 0, sizeof(c->pre_bit_error));
+               memset(&c->pre_bit_count, 0, sizeof(c->pre_bit_count));
+               memset(&c->post_bit_error, 0, sizeof(c->post_bit_error));
+               memset(&c->post_bit_count, 0, sizeof(c->post_bit_count));
+               memset(&c->block_error, 0, sizeof(c->block_error));
+               memset(&c->block_count, 0, sizeof(c->block_count));
+
+               state->last_frequency = c->frequency;
+       }
+
+       /* Clear status for most stats */
+
+       /* BER/PER counter reset */
+       rc = mb86a20s_writeregdata(state, mb86a20s_per_ber_reset);
+       if (rc < 0)
+               goto err;
+
+       /* CNR counter reset */
+       rc = mb86a20s_readreg(state, 0x45);
+       if (rc < 0)
+               goto err;
+       val = rc;
+       rc = mb86a20s_writereg(state, 0x45, val | 0x10);
+       if (rc < 0)
+               goto err;
+       rc = mb86a20s_writereg(state, 0x45, val & 0x6f);
+       if (rc < 0)
+               goto err;
+
+       /* MER counter reset */
+       rc = mb86a20s_writereg(state, 0x50, 0x50);
+       if (rc < 0)
+               goto err;
+       rc = mb86a20s_readreg(state, 0x51);
+       if (rc < 0)
+               goto err;
+       val = rc;
+       rc = mb86a20s_writereg(state, 0x51, val | 0x01);
+       if (rc < 0)
+               goto err;
+       rc = mb86a20s_writereg(state, 0x51, val & 0x06);
+       if (rc < 0)
+               goto err;
+
+       goto ok;
+err:
+       dev_err(&state->i2c->dev,
+               "%s: Can't reset FE statistics (error %d).\n",
+               __func__, rc);
+ok:
+       return rc;
+}
+
+static int mb86a20s_get_pre_ber(struct dvb_frontend *fe,
+                               unsigned layer,
+                               u32 *error, u32 *count)
+{
+       struct mb86a20s_state *state = fe->demodulator_priv;
+       int rc, val;
+
+       dev_dbg(&state->i2c->dev, "%s called.\n", __func__);
+
+       if (layer >= NUM_LAYERS)
+               return -EINVAL;
+
+       /* Check if the BER measures are already available */
+       rc = mb86a20s_readreg(state, 0x54);
+       if (rc < 0)
+               return rc;
+
+       /* Check if data is available for that layer */
+       if (!(rc & (1 << layer))) {
+               dev_dbg(&state->i2c->dev,
+                       "%s: preBER for layer %c is not available yet.\n",
+                       __func__, 'A' + layer);
+               return -EBUSY;
+       }
+
+       /* Read Bit Error Count */
+       rc = mb86a20s_readreg(state, 0x55 + layer * 3);
+       if (rc < 0)
+               return rc;
+       *error = rc << 16;
+       rc = mb86a20s_readreg(state, 0x56 + layer * 3);
+       if (rc < 0)
+               return rc;
+       *error |= rc << 8;
+       rc = mb86a20s_readreg(state, 0x57 + layer * 3);
+       if (rc < 0)
+               return rc;
+       *error |= rc;
+
+       dev_dbg(&state->i2c->dev,
+               "%s: bit error before Viterbi for layer %c: %d.\n",
+               __func__, 'A' + layer, *error);
+
+       /* Read Bit Count */
+       rc = mb86a20s_writereg(state, 0x50, 0xa7 + layer * 3);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_readreg(state, 0x51);
+       if (rc < 0)
+               return rc;
+       *count = rc << 16;
+       rc = mb86a20s_writereg(state, 0x50, 0xa8 + layer * 3);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_readreg(state, 0x51);
+       if (rc < 0)
+               return rc;
+       *count |= rc << 8;
+       rc = mb86a20s_writereg(state, 0x50, 0xa9 + layer * 3);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_readreg(state, 0x51);
+       if (rc < 0)
+               return rc;
+       *count |= rc;
+
+       dev_dbg(&state->i2c->dev,
+               "%s: bit count before Viterbi for layer %c: %d.\n",
+               __func__, 'A' + layer, *count);
+
+
+       /*
+        * As we get TMCC data from the frontend, we can better estimate the
+        * BER bit counters, in order to do the BER measure during a longer
+        * time. Use those data, if available, to update the bit count
+        * measure.
+        */
+
+       if (state->estimated_rate[layer]
+           && state->estimated_rate[layer] != *count) {
+               dev_dbg(&state->i2c->dev,
+                       "%s: updating layer %c preBER counter to %d.\n",
+                       __func__, 'A' + layer, state->estimated_rate[layer]);
+
+               /* Turn off BER before Viterbi */
+               rc = mb86a20s_writereg(state, 0x52, 0x00);
+
+               /* Update counter for this layer */
+               rc = mb86a20s_writereg(state, 0x50, 0xa7 + layer * 3);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x51,
+                                      state->estimated_rate[layer] >> 16);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x50, 0xa8 + layer * 3);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x51,
+                                      state->estimated_rate[layer] >> 8);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x50, 0xa9 + layer * 3);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x51,
+                                      state->estimated_rate[layer]);
+               if (rc < 0)
+                       return rc;
+
+               /* Turn on BER before Viterbi */
+               rc = mb86a20s_writereg(state, 0x52, 0x01);
+
+               /* Reset all preBER counters */
+               rc = mb86a20s_writereg(state, 0x53, 0x00);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x53, 0x07);
+       } else {
+               /* Reset counter to collect new data */
+               rc = mb86a20s_readreg(state, 0x53);
+               if (rc < 0)
+                       return rc;
+               val = rc;
+               rc = mb86a20s_writereg(state, 0x53, val & ~(1 << layer));
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x53, val | (1 << layer));
+       }
+
+       return rc;
+}
+
+static int mb86a20s_get_post_ber(struct dvb_frontend *fe,
+                                unsigned layer,
+                                 u32 *error, u32 *count)
+{
+       struct mb86a20s_state *state = fe->demodulator_priv;
+       u32 counter, collect_rate;
+       int rc, val;
+
+       dev_dbg(&state->i2c->dev, "%s called.\n", __func__);
+
+       if (layer >= NUM_LAYERS)
+               return -EINVAL;
+
+       /* Check if the BER measures are already available */
+       rc = mb86a20s_readreg(state, 0x60);
+       if (rc < 0)
+               return rc;
+
+       /* Check if data is available for that layer */
+       if (!(rc & (1 << layer))) {
+               dev_dbg(&state->i2c->dev,
+                       "%s: post BER for layer %c is not available yet.\n",
+                       __func__, 'A' + layer);
+               return -EBUSY;
+       }
+
+       /* Read Bit Error Count */
+       rc = mb86a20s_readreg(state, 0x64 + layer * 3);
+       if (rc < 0)
+               return rc;
+       *error = rc << 16;
+       rc = mb86a20s_readreg(state, 0x65 + layer * 3);
+       if (rc < 0)
+               return rc;
+       *error |= rc << 8;
+       rc = mb86a20s_readreg(state, 0x66 + layer * 3);
+       if (rc < 0)
+               return rc;
+       *error |= rc;
+
+       dev_dbg(&state->i2c->dev,
+               "%s: post bit error for layer %c: %d.\n",
+               __func__, 'A' + layer, *error);
+
+       /* Read Bit Count */
+       rc = mb86a20s_writereg(state, 0x50, 0xdc + layer * 2);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_readreg(state, 0x51);
+       if (rc < 0)
+               return rc;
+       counter = rc << 8;
+       rc = mb86a20s_writereg(state, 0x50, 0xdd + layer * 2);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_readreg(state, 0x51);
+       if (rc < 0)
+               return rc;
+       counter |= rc;
+       *count = counter * 204 * 8;
+
+       dev_dbg(&state->i2c->dev,
+               "%s: post bit count for layer %c: %d.\n",
+               __func__, 'A' + layer, *count);
+
+       /*
+        * As we get TMCC data from the frontend, we can better estimate the
+        * BER bit counters, in order to do the BER measure during a longer
+        * time. Use those data, if available, to update the bit count
+        * measure.
+        */
+
+       if (!state->estimated_rate[layer])
+               goto reset_measurement;
+
+       collect_rate = state->estimated_rate[layer] / 204 / 8;
+       if (collect_rate < 32)
+               collect_rate = 32;
+       if (collect_rate > 65535)
+               collect_rate = 65535;
+       if (collect_rate != counter) {
+               dev_dbg(&state->i2c->dev,
+                       "%s: updating postBER counter on layer %c to %d.\n",
+                       __func__, 'A' + layer, collect_rate);
+
+               /* Turn off BER after Viterbi */
+               rc = mb86a20s_writereg(state, 0x5e, 0x00);
+
+               /* Update counter for this layer */
+               rc = mb86a20s_writereg(state, 0x50, 0xdc + layer * 2);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x51, collect_rate >> 8);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x50, 0xdd + layer * 2);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x51, collect_rate & 0xff);
+               if (rc < 0)
+                       return rc;
+
+               /* Turn on BER after Viterbi */
+               rc = mb86a20s_writereg(state, 0x5e, 0x07);
+
+               /* Reset all preBER counters */
+               rc = mb86a20s_writereg(state, 0x5f, 0x00);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x5f, 0x07);
+
+               return rc;
+       }
+
+reset_measurement:
+       /* Reset counter to collect new data */
+       rc = mb86a20s_readreg(state, 0x5f);
+       if (rc < 0)
+               return rc;
+       val = rc;
+       rc = mb86a20s_writereg(state, 0x5f, val & ~(1 << layer));
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_writereg(state, 0x5f, val | (1 << layer));
+
+       return rc;
+}
+
+static int mb86a20s_get_blk_error(struct dvb_frontend *fe,
+                           unsigned layer,
+                           u32 *error, u32 *count)
+{
+       struct mb86a20s_state *state = fe->demodulator_priv;
+       int rc, val;
+       u32 collect_rate;
+       dev_dbg(&state->i2c->dev, "%s called.\n", __func__);
+
+       if (layer >= NUM_LAYERS)
+               return -EINVAL;
+
+       /* Check if the PER measures are already available */
+       rc = mb86a20s_writereg(state, 0x50, 0xb8);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_readreg(state, 0x51);
+       if (rc < 0)
+               return rc;
+
+       /* Check if data is available for that layer */
+
+       if (!(rc & (1 << layer))) {
+               dev_dbg(&state->i2c->dev,
+                       "%s: block counts for layer %c aren't available yet.\n",
+                       __func__, 'A' + layer);
+               return -EBUSY;
+       }
+
+       /* Read Packet error Count */
+       rc = mb86a20s_writereg(state, 0x50, 0xb9 + layer * 2);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_readreg(state, 0x51);
+       if (rc < 0)
+               return rc;
+       *error = rc << 8;
+       rc = mb86a20s_writereg(state, 0x50, 0xba + layer * 2);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_readreg(state, 0x51);
+       if (rc < 0)
+               return rc;
+       *error |= rc;
+       dev_dbg(&state->i2c->dev, "%s: block error for layer %c: %d.\n",
+               __func__, 'A' + layer, *error);
+
+       /* Read Bit Count */
+       rc = mb86a20s_writereg(state, 0x50, 0xb2 + layer * 2);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_readreg(state, 0x51);
+       if (rc < 0)
+               return rc;
+       *count = rc << 8;
+       rc = mb86a20s_writereg(state, 0x50, 0xb3 + layer * 2);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_readreg(state, 0x51);
+       if (rc < 0)
+               return rc;
+       *count |= rc;
+
+       dev_dbg(&state->i2c->dev,
+               "%s: block count for layer %c: %d.\n",
+               __func__, 'A' + layer, *count);
+
+       /*
+        * As we get TMCC data from the frontend, we can better estimate the
+        * BER bit counters, in order to do the BER measure during a longer
+        * time. Use those data, if available, to update the bit count
+        * measure.
+        */
+
+       if (!state->estimated_rate[layer])
+               goto reset_measurement;
+
+       collect_rate = state->estimated_rate[layer] / 204 / 8;
+       if (collect_rate < 32)
+               collect_rate = 32;
+       if (collect_rate > 65535)
+               collect_rate = 65535;
+
+       if (collect_rate != *count) {
+               dev_dbg(&state->i2c->dev,
+                       "%s: updating PER counter on layer %c to %d.\n",
+                       __func__, 'A' + layer, collect_rate);
+
+               /* Stop PER measurement */
+               rc = mb86a20s_writereg(state, 0x50, 0xb0);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x51, 0x00);
+               if (rc < 0)
+                       return rc;
+
+               /* Update this layer's counter */
+               rc = mb86a20s_writereg(state, 0x50, 0xb2 + layer * 2);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x51, collect_rate >> 8);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x50, 0xb3 + layer * 2);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x51, collect_rate & 0xff);
+               if (rc < 0)
+                       return rc;
+
+               /* start PER measurement */
+               rc = mb86a20s_writereg(state, 0x50, 0xb0);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x51, 0x07);
+               if (rc < 0)
+                       return rc;
+
+               /* Reset all counters to collect new data */
+               rc = mb86a20s_writereg(state, 0x50, 0xb1);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x51, 0x07);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_writereg(state, 0x51, 0x00);
+
+               return rc;
+       }
+
+reset_measurement:
+       /* Reset counter to collect new data */
+       rc = mb86a20s_writereg(state, 0x50, 0xb1);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_readreg(state, 0x51);
+       if (rc < 0)
+               return rc;
+       val = rc;
+       rc = mb86a20s_writereg(state, 0x51, val | (1 << layer));
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_writereg(state, 0x51, val & ~(1 << layer));
+
+       return rc;
+}
+
+struct linear_segments {
+       unsigned x, y;
+};
+
+/*
+ * All tables below return a dB/1000 measurement
+ */
+
+static const struct linear_segments cnr_to_db_table[] = {
+       { 19648,     0},
+       { 18187,  1000},
+       { 16534,  2000},
+       { 14823,  3000},
+       { 13161,  4000},
+       { 11622,  5000},
+       { 10279,  6000},
+       {  9089,  7000},
+       {  8042,  8000},
+       {  7137,  9000},
+       {  6342, 10000},
+       {  5641, 11000},
+       {  5030, 12000},
+       {  4474, 13000},
+       {  3988, 14000},
+       {  3556, 15000},
+       {  3180, 16000},
+       {  2841, 17000},
+       {  2541, 18000},
+       {  2276, 19000},
+       {  2038, 20000},
+       {  1800, 21000},
+       {  1625, 22000},
+       {  1462, 23000},
+       {  1324, 24000},
+       {  1175, 25000},
+       {  1063, 26000},
+       {   980, 27000},
+       {   907, 28000},
+       {   840, 29000},
+       {   788, 30000},
+};
+
+static const struct linear_segments cnr_64qam_table[] = {
+       { 3922688,     0},
+       { 3920384,  1000},
+       { 3902720,  2000},
+       { 3894784,  3000},
+       { 3882496,  4000},
+       { 3872768,  5000},
+       { 3858944,  6000},
+       { 3851520,  7000},
+       { 3838976,  8000},
+       { 3829248,  9000},
+       { 3818240, 10000},
+       { 3806976, 11000},
+       { 3791872, 12000},
+       { 3767040, 13000},
+       { 3720960, 14000},
+       { 3637504, 15000},
+       { 3498496, 16000},
+       { 3296000, 17000},
+       { 3031040, 18000},
+       { 2715392, 19000},
+       { 2362624, 20000},
+       { 1963264, 21000},
+       { 1649664, 22000},
+       { 1366784, 23000},
+       { 1120768, 24000},
+       {  890880, 25000},
+       {  723456, 26000},
+       {  612096, 27000},
+       {  518912, 28000},
+       {  448256, 29000},
+       {  388864, 30000},
+};
+
+static const struct linear_segments cnr_16qam_table[] = {
+       { 5314816,     0},
+       { 5219072,  1000},
+       { 5118720,  2000},
+       { 4998912,  3000},
+       { 4875520,  4000},
+       { 4736000,  5000},
+       { 4604160,  6000},
+       { 4458752,  7000},
+       { 4300288,  8000},
+       { 4092928,  9000},
+       { 3836160, 10000},
+       { 3521024, 11000},
+       { 3155968, 12000},
+       { 2756864, 13000},
+       { 2347008, 14000},
+       { 1955072, 15000},
+       { 1593600, 16000},
+       { 1297920, 17000},
+       { 1043968, 18000},
+       {  839680, 19000},
+       {  672256, 20000},
+       {  523008, 21000},
+       {  424704, 22000},
+       {  345088, 23000},
+       {  280064, 24000},
+       {  221440, 25000},
+       {  179712, 26000},
+       {  151040, 27000},
+       {  128512, 28000},
+       {  110080, 29000},
+       {   95744, 30000},
+};
+
+static const struct linear_segments cnr_qpsk_table[] = {
+       { 2834176,     0},
+       { 2683648,  1000},
+       { 2536960,  2000},
+       { 2391808,  3000},
+       { 2133248,  4000},
+       { 1906176,  5000},
+       { 1666560,  6000},
+       { 1422080,  7000},
+       { 1189632,  8000},
+       {  976384,  9000},
+       {  790272, 10000},
+       {  633344, 11000},
+       {  505600, 12000},
+       {  402944, 13000},
+       {  320768, 14000},
+       {  255488, 15000},
+       {  204032, 16000},
+       {  163072, 17000},
+       {  130304, 18000},
+       {  105216, 19000},
+       {   83456, 20000},
+       {   65024, 21000},
+       {   52480, 22000},
+       {   42752, 23000},
+       {   34560, 24000},
+       {   27136, 25000},
+       {   22016, 26000},
+       {   18432, 27000},
+       {   15616, 28000},
+       {   13312, 29000},
+       {   11520, 30000},
+};
+
+static u32 interpolate_value(u32 value, const struct linear_segments *segments,
+                            unsigned len)
+{
+       u64 tmp64;
+       u32 dx, dy;
+       int i, ret;
+
+       if (value >= segments[0].x)
+               return segments[0].y;
+       if (value < segments[len-1].x)
+               return segments[len-1].y;
+
+       for (i = 1; i < len - 1; i++) {
+               /* If value is identical, no need to interpolate */
+               if (value == segments[i].x)
+                       return segments[i].y;
+               if (value > segments[i].x)
+                       break;
+       }
+
+       /* Linear interpolation between the two (x,y) points */
+       dy = segments[i].y - segments[i - 1].y;
+       dx = segments[i - 1].x - segments[i].x;
+       tmp64 = value - segments[i].x;
+       tmp64 *= dy;
+       do_div(tmp64, dx);
+       ret = segments[i].y - tmp64;
+
+       return ret;
+}
+
+static int mb86a20s_get_main_CNR(struct dvb_frontend *fe)
+{
+       struct mb86a20s_state *state = fe->demodulator_priv;
+       struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+       u32 cnr_linear, cnr;
+       int rc, val;
+
+       /* Check if CNR is available */
+       rc = mb86a20s_readreg(state, 0x45);
+       if (rc < 0)
+               return rc;
+
+       if (!(rc & 0x40)) {
+               dev_dbg(&state->i2c->dev, "%s: CNR is not available yet.\n",
+                        __func__);
+               return -EBUSY;
+       }
+       val = rc;
+
+       rc = mb86a20s_readreg(state, 0x46);
+       if (rc < 0)
+               return rc;
+       cnr_linear = rc << 8;
+
+       rc = mb86a20s_readreg(state, 0x46);
+       if (rc < 0)
+               return rc;
+       cnr_linear |= rc;
+
+       cnr = interpolate_value(cnr_linear,
+                               cnr_to_db_table, ARRAY_SIZE(cnr_to_db_table));
+
+       c->cnr.stat[0].scale = FE_SCALE_DECIBEL;
+       c->cnr.stat[0].svalue = cnr;
+
+       dev_dbg(&state->i2c->dev, "%s: CNR is %d.%03d dB (%d)\n",
+               __func__, cnr / 1000, cnr % 1000, cnr_linear);
+
+       /* CNR counter reset */
+       rc = mb86a20s_writereg(state, 0x45, val | 0x10);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_writereg(state, 0x45, val & 0x6f);
+
+       return rc;
+}
+
+static int mb86a20s_get_blk_error_layer_CNR(struct dvb_frontend *fe)
+{
+       struct mb86a20s_state *state = fe->demodulator_priv;
+       struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+       u32 mer, cnr;
+       int rc, val, layer;
+       const struct linear_segments *segs;
+       unsigned segs_len;
+
+       dev_dbg(&state->i2c->dev, "%s called.\n", __func__);
+
+       /* Check if the measures are already available */
+       rc = mb86a20s_writereg(state, 0x50, 0x5b);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_readreg(state, 0x51);
+       if (rc < 0)
+               return rc;
+
+       /* Check if data is available */
+       if (!(rc & 0x01)) {
+               dev_dbg(&state->i2c->dev,
+                       "%s: MER measures aren't available yet.\n", __func__);
+               return -EBUSY;
+       }
+
+       /* Read all layers */
+       for (layer = 0; layer < NUM_LAYERS; layer++) {
+               if (!(c->isdbt_layer_enabled & (1 << layer))) {
+                       c->cnr.stat[1 + layer].scale = FE_SCALE_NOT_AVAILABLE;
+                       continue;
+               }
+
+               rc = mb86a20s_writereg(state, 0x50, 0x52 + layer * 3);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_readreg(state, 0x51);
+               if (rc < 0)
+                       return rc;
+               mer = rc << 16;
+               rc = mb86a20s_writereg(state, 0x50, 0x53 + layer * 3);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_readreg(state, 0x51);
+               if (rc < 0)
+                       return rc;
+               mer |= rc << 8;
+               rc = mb86a20s_writereg(state, 0x50, 0x54 + layer * 3);
+               if (rc < 0)
+                       return rc;
+               rc = mb86a20s_readreg(state, 0x51);
+               if (rc < 0)
+                       return rc;
+               mer |= rc;
+
+               switch (c->layer[layer].modulation) {
+               case DQPSK:
+               case QPSK:
+                       segs = cnr_qpsk_table;
+                       segs_len = ARRAY_SIZE(cnr_qpsk_table);
+                       break;
+               case QAM_16:
+                       segs = cnr_16qam_table;
+                       segs_len = ARRAY_SIZE(cnr_16qam_table);
+                       break;
+               default:
+               case QAM_64:
+                       segs = cnr_64qam_table;
+                       segs_len = ARRAY_SIZE(cnr_64qam_table);
+                       break;
+               }
+               cnr = interpolate_value(mer, segs, segs_len);
+
+               c->cnr.stat[1 + layer].scale = FE_SCALE_DECIBEL;
+               c->cnr.stat[1 + layer].svalue = cnr;
+
+               dev_dbg(&state->i2c->dev,
+                       "%s: CNR for layer %c is %d.%03d dB (MER = %d).\n",
+                       __func__, 'A' + layer, cnr / 1000, cnr % 1000, mer);
+
+       }
+
+       /* Start a new MER measurement */
+       /* MER counter reset */
+       rc = mb86a20s_writereg(state, 0x50, 0x50);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_readreg(state, 0x51);
+       if (rc < 0)
+               return rc;
+       val = rc;
+
+       rc = mb86a20s_writereg(state, 0x51, val | 0x01);
+       if (rc < 0)
+               return rc;
+       rc = mb86a20s_writereg(state, 0x51, val & 0x06);
+       if (rc < 0)
+               return rc;
+
+       return 0;
+}
+
+static void mb86a20s_stats_not_ready(struct dvb_frontend *fe)
+{
+       struct mb86a20s_state *state = fe->demodulator_priv;
+       struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+       int layer;
+
+       dev_dbg(&state->i2c->dev, "%s called.\n", __func__);
+
+       /* Fill the length of each status counter */
+
+       /* Only global stats */
+       c->strength.len = 1;
+
+       /* Per-layer stats - 3 layers + global */
+       c->cnr.len = NUM_LAYERS + 1;
+       c->pre_bit_error.len = NUM_LAYERS + 1;
+       c->pre_bit_count.len = NUM_LAYERS + 1;
+       c->post_bit_error.len = NUM_LAYERS + 1;
+       c->post_bit_count.len = NUM_LAYERS + 1;
+       c->block_error.len = NUM_LAYERS + 1;
+       c->block_count.len = NUM_LAYERS + 1;
+
+       /* Signal is always available */
+       c->strength.stat[0].scale = FE_SCALE_RELATIVE;
+       c->strength.stat[0].uvalue = 0;
+
+       /* Put all of them at FE_SCALE_NOT_AVAILABLE */
+       for (layer = 0; layer < NUM_LAYERS + 1; layer++) {
+               c->cnr.stat[layer].scale = FE_SCALE_NOT_AVAILABLE;
+               c->pre_bit_error.stat[layer].scale = FE_SCALE_NOT_AVAILABLE;
+               c->pre_bit_count.stat[layer].scale = FE_SCALE_NOT_AVAILABLE;
+               c->post_bit_error.stat[layer].scale = FE_SCALE_NOT_AVAILABLE;
+               c->post_bit_count.stat[layer].scale = FE_SCALE_NOT_AVAILABLE;
+               c->block_error.stat[layer].scale = FE_SCALE_NOT_AVAILABLE;
+               c->block_count.stat[layer].scale = FE_SCALE_NOT_AVAILABLE;
+       }
+}
+
+static int mb86a20s_get_stats(struct dvb_frontend *fe, int status_nr)
+{
+       struct mb86a20s_state *state = fe->demodulator_priv;
+       struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+       int rc = 0, layer;
+       u32 bit_error = 0, bit_count = 0;
+       u32 t_pre_bit_error = 0, t_pre_bit_count = 0;
+       u32 t_post_bit_error = 0, t_post_bit_count = 0;
+       u32 block_error = 0, block_count = 0;
+       u32 t_block_error = 0, t_block_count = 0;
+       int active_layers = 0, pre_ber_layers = 0, post_ber_layers = 0;
+       int per_layers = 0;
+
+       dev_dbg(&state->i2c->dev, "%s called.\n", __func__);
+
+       mb86a20s_get_main_CNR(fe);
+
+       /* Get per-layer stats */
+       mb86a20s_get_blk_error_layer_CNR(fe);
+
+       /*
+        * At state 7, only CNR is available
+        * For BER measures, state=9 is required
+        * FIXME: we may get MER measures with state=8
+        */
+       if (status_nr < 9)
+               return 0;
+
+       for (layer = 0; layer < NUM_LAYERS; layer++) {
+               if (c->isdbt_layer_enabled & (1 << layer)) {
+                       /* Layer is active and has rc segments */
+                       active_layers++;
+
+                       /* Handle BER before vterbi */
+                       rc = mb86a20s_get_pre_ber(fe, layer,
+                                                 &bit_error, &bit_count);
+                       if (rc >= 0) {
+                               c->pre_bit_error.stat[1 + layer].scale = FE_SCALE_COUNTER;
+                               c->pre_bit_error.stat[1 + layer].uvalue += bit_error;
+                               c->pre_bit_count.stat[1 + layer].scale = FE_SCALE_COUNTER;
+                               c->pre_bit_count.stat[1 + layer].uvalue += bit_count;
+                       } else if (rc != -EBUSY) {
+                               /*
+                                       * If an I/O error happened,
+                                       * measures are now unavailable
+                                       */
+                               c->pre_bit_error.stat[1 + layer].scale = FE_SCALE_NOT_AVAILABLE;
+                               c->pre_bit_count.stat[1 + layer].scale = FE_SCALE_NOT_AVAILABLE;
+                               dev_err(&state->i2c->dev,
+                                       "%s: Can't get BER for layer %c (error %d).\n",
+                                       __func__, 'A' + layer, rc);
+                       }
+                       if (c->block_error.stat[1 + layer].scale != FE_SCALE_NOT_AVAILABLE)
+                               pre_ber_layers++;
+
+                       /* Handle BER post vterbi */
+                       rc = mb86a20s_get_post_ber(fe, layer,
+                                                  &bit_error, &bit_count);
+                       if (rc >= 0) {
+                               c->post_bit_error.stat[1 + layer].scale = FE_SCALE_COUNTER;
+                               c->post_bit_error.stat[1 + layer].uvalue += bit_error;
+                               c->post_bit_count.stat[1 + layer].scale = FE_SCALE_COUNTER;
+                               c->post_bit_count.stat[1 + layer].uvalue += bit_count;
+                       } else if (rc != -EBUSY) {
+                               /*
+                                       * If an I/O error happened,
+                                       * measures are now unavailable
+                                       */
+                               c->post_bit_error.stat[1 + layer].scale = FE_SCALE_NOT_AVAILABLE;
+                               c->post_bit_count.stat[1 + layer].scale = FE_SCALE_NOT_AVAILABLE;
+                               dev_err(&state->i2c->dev,
+                                       "%s: Can't get BER for layer %c (error %d).\n",
+                                       __func__, 'A' + layer, rc);
+                       }
+                       if (c->block_error.stat[1 + layer].scale != FE_SCALE_NOT_AVAILABLE)
+                               post_ber_layers++;
+
+                       /* Handle Block errors for PER/UCB reports */
+                       rc = mb86a20s_get_blk_error(fe, layer,
+                                               &block_error,
+                                               &block_count);
+                       if (rc >= 0) {
+                               c->block_error.stat[1 + layer].scale = FE_SCALE_COUNTER;
+                               c->block_error.stat[1 + layer].uvalue += block_error;
+                               c->block_count.stat[1 + layer].scale = FE_SCALE_COUNTER;
+                               c->block_count.stat[1 + layer].uvalue += block_count;
+                       } else if (rc != -EBUSY) {
+                               /*
+                                       * If an I/O error happened,
+                                       * measures are now unavailable
+                                       */
+                               c->block_error.stat[1 + layer].scale = FE_SCALE_NOT_AVAILABLE;
+                               c->block_count.stat[1 + layer].scale = FE_SCALE_NOT_AVAILABLE;
+                               dev_err(&state->i2c->dev,
+                                       "%s: Can't get PER for layer %c (error %d).\n",
+                                       __func__, 'A' + layer, rc);
+
+                       }
+                       if (c->block_error.stat[1 + layer].scale != FE_SCALE_NOT_AVAILABLE)
+                               per_layers++;
+
+                       /* Update total preBER */
+                       t_pre_bit_error += c->pre_bit_error.stat[1 + layer].uvalue;
+                       t_pre_bit_count += c->pre_bit_count.stat[1 + layer].uvalue;
+
+                       /* Update total postBER */
+                       t_post_bit_error += c->post_bit_error.stat[1 + layer].uvalue;
+                       t_post_bit_count += c->post_bit_count.stat[1 + layer].uvalue;
+
+                       /* Update total PER */
+                       t_block_error += c->block_error.stat[1 + layer].uvalue;
+                       t_block_count += c->block_count.stat[1 + layer].uvalue;
+               }
+       }
+
+       /*
+        * Start showing global count if at least one error count is
+        * available.
+        */
+       if (pre_ber_layers) {
+               /*
+                * At least one per-layer BER measure was read. We can now
+                * calculate the total BER
+                *
+                * Total Bit Error/Count is calculated as the sum of the
+                * bit errors on all active layers.
+                */
+               c->pre_bit_error.stat[0].scale = FE_SCALE_COUNTER;
+               c->pre_bit_error.stat[0].uvalue = t_pre_bit_error;
+               c->pre_bit_count.stat[0].scale = FE_SCALE_COUNTER;
+               c->pre_bit_count.stat[0].uvalue = t_pre_bit_count;
+       } else {
+               c->pre_bit_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
+               c->pre_bit_count.stat[0].scale = FE_SCALE_COUNTER;
+       }
+
+       /*
+        * Start showing global count if at least one error count is
+        * available.
+        */
+       if (post_ber_layers) {
+               /*
+                * At least one per-layer BER measure was read. We can now
+                * calculate the total BER
+                *
+                * Total Bit Error/Count is calculated as the sum of the
+                * bit errors on all active layers.
+                */
+               c->post_bit_error.stat[0].scale = FE_SCALE_COUNTER;
+               c->post_bit_error.stat[0].uvalue = t_post_bit_error;
+               c->post_bit_count.stat[0].scale = FE_SCALE_COUNTER;
+               c->post_bit_count.stat[0].uvalue = t_post_bit_count;
+       } else {
+               c->post_bit_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
+               c->post_bit_count.stat[0].scale = FE_SCALE_COUNTER;
+       }
+
+       if (per_layers) {
+               /*
+                * At least one per-layer UCB measure was read. We can now
+                * calculate the total UCB
+                *
+                * Total block Error/Count is calculated as the sum of the
+                * block errors on all active layers.
+                */
+               c->block_error.stat[0].scale = FE_SCALE_COUNTER;
+               c->block_error.stat[0].uvalue = t_block_error;
+               c->block_count.stat[0].scale = FE_SCALE_COUNTER;
+               c->block_count.stat[0].uvalue = t_block_count;
+       } else {
+               c->block_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
+               c->block_count.stat[0].scale = FE_SCALE_COUNTER;
+       }
+
+       return rc;
+}
+
+/*
+ * The functions below are called via DVB callbacks, so they need to
+ * properly use the I2C gate control
+ */
+
+static int mb86a20s_initfe(struct dvb_frontend *fe)
+{
+       struct mb86a20s_state *state = fe->demodulator_priv;
+       u64 pll;
+       u32 fclk;
+       int rc;
+       u8  regD5 = 1, reg71, reg09 = 0x3a;
+
+       dev_dbg(&state->i2c->dev, "%s called.\n", __func__);
+
+       if (fe->ops.i2c_gate_ctrl)
+               fe->ops.i2c_gate_ctrl(fe, 0);
+
+       /* Initialize the frontend */
+       rc = mb86a20s_writeregdata(state, mb86a20s_init1);
+       if (rc < 0)
+               goto err;
+
+       if (!state->inversion)
+               reg09 |= 0x04;
+       rc = mb86a20s_writereg(state, 0x09, reg09);
+       if (rc < 0)
+               goto err;
+       if (!state->bw)
+               reg71 = 1;
+       else
+               reg71 = 0;
+       rc = mb86a20s_writereg(state, 0x39, reg71);
+       if (rc < 0)
+               goto err;
+       rc = mb86a20s_writereg(state, 0x71, state->bw);
+       if (rc < 0)
+               goto err;
+       if (state->subchannel) {
+               rc = mb86a20s_writereg(state, 0x44, state->subchannel);
+               if (rc < 0)
+                       goto err;
+       }
+
+       fclk = state->config->fclk;
+       if (!fclk)
+               fclk = 32571428;
+
+       /* Adjust IF frequency to match tuner */
+       if (fe->ops.tuner_ops.get_if_frequency)
+               fe->ops.tuner_ops.get_if_frequency(fe, &state->if_freq);
+
+       if (!state->if_freq)
+               state->if_freq = 3300000;
+
+       pll = (((u64)1) << 34) * state->if_freq;
+       do_div(pll, 63 * fclk);
+       pll = (1 << 25) - pll;
+       rc = mb86a20s_writereg(state, 0x28, 0x2a);
+       if (rc < 0)
+               goto err;
+       rc = mb86a20s_writereg(state, 0x29, (pll >> 16) & 0xff);
+       if (rc < 0)
+               goto err;
+       rc = mb86a20s_writereg(state, 0x2a, (pll >> 8) & 0xff);
+       if (rc < 0)
+               goto err;
+       rc = mb86a20s_writereg(state, 0x2b, pll & 0xff);
+       if (rc < 0)
+               goto err;
+       dev_dbg(&state->i2c->dev, "%s: fclk=%d, IF=%d, clock reg=0x%06llx\n",
+               __func__, fclk, state->if_freq, (long long)pll);
+
+       /* pll = freq[Hz] * 2^24/10^6 / 16.285714286 */
+       pll = state->if_freq * 1677721600L;
+       do_div(pll, 1628571429L);
+       rc = mb86a20s_writereg(state, 0x28, 0x20);
+       if (rc < 0)
+               goto err;
+       rc = mb86a20s_writereg(state, 0x29, (pll >> 16) & 0xff);
+       if (rc < 0)
+               goto err;
+       rc = mb86a20s_writereg(state, 0x2a, (pll >> 8) & 0xff);
+       if (rc < 0)
+               goto err;
+       rc = mb86a20s_writereg(state, 0x2b, pll & 0xff);
+       if (rc < 0)
+               goto err;
+       dev_dbg(&state->i2c->dev, "%s: IF=%d, IF reg=0x%06llx\n",
+               __func__, state->if_freq, (long long)pll);
+
+       if (!state->config->is_serial)
+               regD5 &= ~1;
+
+       rc = mb86a20s_writereg(state, 0x50, 0xd5);
+       if (rc < 0)
+               goto err;
+       rc = mb86a20s_writereg(state, 0x51, regD5);
+       if (rc < 0)
+               goto err;
+
+       rc = mb86a20s_writeregdata(state, mb86a20s_init2);
+       if (rc < 0)
+               goto err;
+
+
+err:
+       if (fe->ops.i2c_gate_ctrl)
+               fe->ops.i2c_gate_ctrl(fe, 1);
+
+       if (rc < 0) {
+               state->need_init = true;
+               dev_info(&state->i2c->dev,
+                        "mb86a20s: Init failed. Will try again later\n");
+       } else {
+               state->need_init = false;
+               dev_dbg(&state->i2c->dev, "Initialization succeeded.\n");
+       }
+       return rc;
+}
+
+static int mb86a20s_set_frontend(struct dvb_frontend *fe)
+{
+       struct mb86a20s_state *state = fe->demodulator_priv;
+       struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+       int rc, if_freq;
+       dev_dbg(&state->i2c->dev, "%s called.\n", __func__);
+
+       if (!c->isdbt_layer_enabled)
+               c->isdbt_layer_enabled = 7;
+
+       if (c->isdbt_layer_enabled == 1)
+               state->bw = MB86A20S_1SEG;
+       else if (c->isdbt_partial_reception)
+               state->bw = MB86A20S_13SEG_PARTIAL;
+       else
+               state->bw = MB86A20S_13SEG;
+
+       if (c->inversion == INVERSION_ON)
+               state->inversion = true;
+       else
+               state->inversion = false;
+
+       if (!c->isdbt_sb_mode) {
+               state->subchannel = 0;
+       } else {
+               if (c->isdbt_sb_subchannel >= ARRAY_SIZE(mb86a20s_subchannel))
+                       c->isdbt_sb_subchannel = 0;
+
+               state->subchannel = mb86a20s_subchannel[c->isdbt_sb_subchannel];
+       }
+
+       /*
+        * Gate should already be opened, but it doesn't hurt to
+        * double-check
+        */
+       if (fe->ops.i2c_gate_ctrl)
+               fe->ops.i2c_gate_ctrl(fe, 1);
+       fe->ops.tuner_ops.set_params(fe);
+
+       if (fe->ops.tuner_ops.get_if_frequency)
+               fe->ops.tuner_ops.get_if_frequency(fe, &if_freq);
+
+       /*
+        * Make it more reliable: if, for some reason, the initial
+        * device initialization doesn't happen, initialize it when
+        * a SBTVD parameters are adjusted.
+        *
+        * Unfortunately, due to a hard to track bug at tda829x/tda18271,
+        * the agc callback logic is not called during DVB attach time,
+        * causing mb86a20s to not be initialized with Kworld SBTVD.
+        * So, this hack is needed, in order to make Kworld SBTVD to work.
+        *
+        * It is also needed to change the IF after the initial init.
+        *
+        * HACK: Always init the frontend when set_frontend is called:
+        * it was noticed that, on some devices, it fails to lock on a
+        * different channel. So, it is better to reset everything, even
+        * wasting some time, than to loose channel lock.
+        */
+       mb86a20s_initfe(fe);
+
+       if (fe->ops.i2c_gate_ctrl)
+               fe->ops.i2c_gate_ctrl(fe, 0);
+
+       rc = mb86a20s_writeregdata(state, mb86a20s_reset_reception);
+       mb86a20s_reset_counters(fe);
+       mb86a20s_stats_not_ready(fe);
+
+       if (fe->ops.i2c_gate_ctrl)
+               fe->ops.i2c_gate_ctrl(fe, 1);
+
+       return rc;
+}
+
+static int mb86a20s_read_status_and_stats(struct dvb_frontend *fe,
+                                         fe_status_t *status)
+{
+       struct mb86a20s_state *state = fe->demodulator_priv;
+       int rc, status_nr;
+
+       dev_dbg(&state->i2c->dev, "%s called.\n", __func__);
+
+       if (fe->ops.i2c_gate_ctrl)
+               fe->ops.i2c_gate_ctrl(fe, 0);
+
+       /* Get lock */
+       status_nr = mb86a20s_read_status(fe, status);
+       if (status_nr < 7) {
+               mb86a20s_stats_not_ready(fe);
+               mb86a20s_reset_frontend_cache(fe);
+       }
+       if (status_nr < 0) {
+               dev_err(&state->i2c->dev,
+                       "%s: Can't read frontend lock status\n", __func__);
+               goto error;
+       }
+
+       /* Get signal strength */
+       rc = mb86a20s_read_signal_strength(fe);
+       if (rc < 0) {
+               dev_err(&state->i2c->dev,
+                       "%s: Can't reset VBER registers.\n", __func__);
+               mb86a20s_stats_not_ready(fe);
+               mb86a20s_reset_frontend_cache(fe);
+
+               rc = 0;         /* Status is OK */
+               goto error;
+       }
+
+       if (status_nr >= 7) {
+               /* Get TMCC info*/
+               rc = mb86a20s_get_frontend(fe);
+               if (rc < 0) {
+                       dev_err(&state->i2c->dev,
+                               "%s: Can't get FE TMCC data.\n", __func__);
+                       rc = 0;         /* Status is OK */
+                       goto error;
+               }
+
+               /* Get statistics */
+               rc = mb86a20s_get_stats(fe, status_nr);
+               if (rc < 0 && rc != -EBUSY) {
+                       dev_err(&state->i2c->dev,
+                               "%s: Can't get FE statistics.\n", __func__);
+                       rc = 0;
+                       goto error;
+               }
+               rc = 0; /* Don't return EBUSY to userspace */
+       }
+       goto ok;
+
+error:
+       mb86a20s_stats_not_ready(fe);
+
+ok:
+       if (fe->ops.i2c_gate_ctrl)
+               fe->ops.i2c_gate_ctrl(fe, 1);
+
+       return rc;
+}
+
+static int mb86a20s_read_signal_strength_from_cache(struct dvb_frontend *fe,
+                                                   u16 *strength)
+{
+       struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+
+
+       *strength = c->strength.stat[0].uvalue;
+
+       return 0;
+}
+
+static int mb86a20s_get_frontend_dummy(struct dvb_frontend *fe)
+{
+       /*
+        * get_frontend is now handled together with other stats
+        * retrival, when read_status() is called, as some statistics
+        * will depend on the layers detection.
+        */
+       return 0;
+};
+
+static int mb86a20s_tune(struct dvb_frontend *fe,
+                       bool re_tune,
+                       unsigned int mode_flags,
+                       unsigned int *delay,
+                       fe_status_t *status)
+{
+       struct mb86a20s_state *state = fe->demodulator_priv;
+       int rc = 0;
+
+       dev_dbg(&state->i2c->dev, "%s called.\n", __func__);
+
+       if (re_tune)
+               rc = mb86a20s_set_frontend(fe);
+
+       if (!(mode_flags & FE_TUNE_MODE_ONESHOT))
+               mb86a20s_read_status_and_stats(fe, status);
+
+       return rc;
+}
+
+static void mb86a20s_release(struct dvb_frontend *fe)
+{
+       struct mb86a20s_state *state = fe->demodulator_priv;
+
+       dev_dbg(&state->i2c->dev, "%s called.\n", __func__);
+
+       kfree(state);
+}
+
+static struct dvb_frontend_ops mb86a20s_ops;
+
+struct dvb_frontend *mb86a20s_attach(const struct mb86a20s_config *config,
+                                   struct i2c_adapter *i2c)
+{
+       struct mb86a20s_state *state;
+       u8      rev;
+
+       dev_dbg(&i2c->dev, "%s called.\n", __func__);
+
+       /* allocate memory for the internal state */
+       state = kzalloc(sizeof(struct mb86a20s_state), GFP_KERNEL);
+       if (state == NULL) {
+               dev_err(&i2c->dev,
+                       "%s: unable to allocate memory for state\n", __func__);
+               goto error;
+       }
+
+       /* setup the state */
+       state->config = config;
+       state->i2c = i2c;
+
+       /* create dvb_frontend */
+       memcpy(&state->frontend.ops, &mb86a20s_ops,
+               sizeof(struct dvb_frontend_ops));
+       state->frontend.demodulator_priv = state;
+
+       /* Check if it is a mb86a20s frontend */
+       rev = mb86a20s_readreg(state, 0);
+
+       if (rev == 0x13) {
+               dev_info(&i2c->dev,
+                        "Detected a Fujitsu mb86a20s frontend\n");
+       } else {
+               dev_dbg(&i2c->dev,
+                       "Frontend revision %d is unknown - aborting.\n",
+                      rev);
+               goto error;
+       }
+
+       return &state->frontend;
+
+error:
+       kfree(state);
+       return NULL;
+}
+EXPORT_SYMBOL(mb86a20s_attach);
+
+static struct dvb_frontend_ops mb86a20s_ops = {
+       .delsys = { SYS_ISDBT },
+       /* Use dib8000 values per default */
+       .info = {
+               .name = "Fujitsu mb86A20s",
+               .caps = FE_CAN_RECOVER  |
+                       FE_CAN_FEC_1_2  | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 |
+                       FE_CAN_FEC_5_6  | FE_CAN_FEC_7_8 | FE_CAN_FEC_AUTO |
+                       FE_CAN_QPSK     | FE_CAN_QAM_16  | FE_CAN_QAM_64 |
+                       FE_CAN_TRANSMISSION_MODE_AUTO | FE_CAN_QAM_AUTO |
+                       FE_CAN_GUARD_INTERVAL_AUTO    | FE_CAN_HIERARCHY_AUTO,
+               /* Actually, those values depend on the used tuner */
+               .frequency_min = 45000000,
+               .frequency_max = 864000000,
+               .frequency_stepsize = 62500,
+       },
+
+       .release = mb86a20s_release,
+
+       .init = mb86a20s_initfe,
+       .set_frontend = mb86a20s_set_frontend,
+       .get_frontend = mb86a20s_get_frontend_dummy,
+       .read_status = mb86a20s_read_status_and_stats,
+       .read_signal_strength = mb86a20s_read_signal_strength_from_cache,
+       .tune = mb86a20s_tune,
+};
+
+MODULE_DESCRIPTION("DVB Frontend module for Fujitsu mb86A20s hardware");
+MODULE_AUTHOR("Mauro Carvalho Chehab");
+MODULE_LICENSE("GPL");