Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / media / i2c / cx25840 / cx25840-ir.c
diff --git a/kernel/drivers/media/i2c/cx25840/cx25840-ir.c b/kernel/drivers/media/i2c/cx25840/cx25840-ir.c
new file mode 100644 (file)
index 0000000..4cf8f18
--- /dev/null
@@ -0,0 +1,1276 @@
+/*
+ *  Driver for the Conexant CX2584x Audio/Video decoder chip and related cores
+ *
+ *  Integrated Consumer Infrared Controller
+ *
+ *  Copyright (C) 2010  Andy Walls <awalls@md.metrocast.net>
+ *
+ *  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; either version 2
+ *  of the License, or (at your option) any later version.
+ *
+ *  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.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ *  02110-1301, USA.
+ */
+
+#include <linux/slab.h>
+#include <linux/kfifo.h>
+#include <linux/module.h>
+#include <media/cx25840.h>
+#include <media/rc-core.h>
+
+#include "cx25840-core.h"
+
+static unsigned int ir_debug;
+module_param(ir_debug, int, 0644);
+MODULE_PARM_DESC(ir_debug, "enable integrated IR debug messages");
+
+#define CX25840_IR_REG_BASE    0x200
+
+#define CX25840_IR_CNTRL_REG   0x200
+#define CNTRL_WIN_3_3  0x00000000
+#define CNTRL_WIN_4_3  0x00000001
+#define CNTRL_WIN_3_4  0x00000002
+#define CNTRL_WIN_4_4  0x00000003
+#define CNTRL_WIN      0x00000003
+#define CNTRL_EDG_NONE 0x00000000
+#define CNTRL_EDG_FALL 0x00000004
+#define CNTRL_EDG_RISE 0x00000008
+#define CNTRL_EDG_BOTH 0x0000000C
+#define CNTRL_EDG      0x0000000C
+#define CNTRL_DMD      0x00000010
+#define CNTRL_MOD      0x00000020
+#define CNTRL_RFE      0x00000040
+#define CNTRL_TFE      0x00000080
+#define CNTRL_RXE      0x00000100
+#define CNTRL_TXE      0x00000200
+#define CNTRL_RIC      0x00000400
+#define CNTRL_TIC      0x00000800
+#define CNTRL_CPL      0x00001000
+#define CNTRL_LBM      0x00002000
+#define CNTRL_R                0x00004000
+
+#define CX25840_IR_TXCLK_REG   0x204
+#define TXCLK_TCD      0x0000FFFF
+
+#define CX25840_IR_RXCLK_REG   0x208
+#define RXCLK_RCD      0x0000FFFF
+
+#define CX25840_IR_CDUTY_REG   0x20C
+#define CDUTY_CDC      0x0000000F
+
+#define CX25840_IR_STATS_REG   0x210
+#define STATS_RTO      0x00000001
+#define STATS_ROR      0x00000002
+#define STATS_RBY      0x00000004
+#define STATS_TBY      0x00000008
+#define STATS_RSR      0x00000010
+#define STATS_TSR      0x00000020
+
+#define CX25840_IR_IRQEN_REG   0x214
+#define IRQEN_RTE      0x00000001
+#define IRQEN_ROE      0x00000002
+#define IRQEN_RSE      0x00000010
+#define IRQEN_TSE      0x00000020
+#define IRQEN_MSK      0x00000033
+
+#define CX25840_IR_FILTR_REG   0x218
+#define FILTR_LPF      0x0000FFFF
+
+#define CX25840_IR_FIFO_REG    0x23C
+#define FIFO_RXTX      0x0000FFFF
+#define FIFO_RXTX_LVL  0x00010000
+#define FIFO_RXTX_RTO  0x0001FFFF
+#define FIFO_RX_NDV    0x00020000
+#define FIFO_RX_DEPTH  8
+#define FIFO_TX_DEPTH  8
+
+#define CX25840_VIDCLK_FREQ    108000000 /* 108 MHz, BT.656 */
+#define CX25840_IR_REFCLK_FREQ (CX25840_VIDCLK_FREQ / 2)
+
+/*
+ * We use this union internally for convenience, but callers to tx_write
+ * and rx_read will be expecting records of type struct ir_raw_event.
+ * Always ensure the size of this union is dictated by struct ir_raw_event.
+ */
+union cx25840_ir_fifo_rec {
+       u32 hw_fifo_data;
+       struct ir_raw_event ir_core_data;
+};
+
+#define CX25840_IR_RX_KFIFO_SIZE    (256 * sizeof(union cx25840_ir_fifo_rec))
+#define CX25840_IR_TX_KFIFO_SIZE    (256 * sizeof(union cx25840_ir_fifo_rec))
+
+struct cx25840_ir_state {
+       struct i2c_client *c;
+
+       struct v4l2_subdev_ir_parameters rx_params;
+       struct mutex rx_params_lock; /* protects Rx parameter settings cache */
+       atomic_t rxclk_divider;
+       atomic_t rx_invert;
+
+       struct kfifo rx_kfifo;
+       spinlock_t rx_kfifo_lock; /* protect Rx data kfifo */
+
+       struct v4l2_subdev_ir_parameters tx_params;
+       struct mutex tx_params_lock; /* protects Tx parameter settings cache */
+       atomic_t txclk_divider;
+};
+
+static inline struct cx25840_ir_state *to_ir_state(struct v4l2_subdev *sd)
+{
+       struct cx25840_state *state = to_state(sd);
+       return state ? state->ir_state : NULL;
+}
+
+
+/*
+ * Rx and Tx Clock Divider register computations
+ *
+ * Note the largest clock divider value of 0xffff corresponds to:
+ *     (0xffff + 1) * 1000 / 108/2 MHz = 1,213,629.629... ns
+ * which fits in 21 bits, so we'll use unsigned int for time arguments.
+ */
+static inline u16 count_to_clock_divider(unsigned int d)
+{
+       if (d > RXCLK_RCD + 1)
+               d = RXCLK_RCD;
+       else if (d < 2)
+               d = 1;
+       else
+               d--;
+       return (u16) d;
+}
+
+static inline u16 ns_to_clock_divider(unsigned int ns)
+{
+       return count_to_clock_divider(
+               DIV_ROUND_CLOSEST(CX25840_IR_REFCLK_FREQ / 1000000 * ns, 1000));
+}
+
+static inline unsigned int clock_divider_to_ns(unsigned int divider)
+{
+       /* Period of the Rx or Tx clock in ns */
+       return DIV_ROUND_CLOSEST((divider + 1) * 1000,
+                                CX25840_IR_REFCLK_FREQ / 1000000);
+}
+
+static inline u16 carrier_freq_to_clock_divider(unsigned int freq)
+{
+       return count_to_clock_divider(
+                         DIV_ROUND_CLOSEST(CX25840_IR_REFCLK_FREQ, freq * 16));
+}
+
+static inline unsigned int clock_divider_to_carrier_freq(unsigned int divider)
+{
+       return DIV_ROUND_CLOSEST(CX25840_IR_REFCLK_FREQ, (divider + 1) * 16);
+}
+
+static inline u16 freq_to_clock_divider(unsigned int freq,
+                                       unsigned int rollovers)
+{
+       return count_to_clock_divider(
+                  DIV_ROUND_CLOSEST(CX25840_IR_REFCLK_FREQ, freq * rollovers));
+}
+
+static inline unsigned int clock_divider_to_freq(unsigned int divider,
+                                                unsigned int rollovers)
+{
+       return DIV_ROUND_CLOSEST(CX25840_IR_REFCLK_FREQ,
+                                (divider + 1) * rollovers);
+}
+
+/*
+ * Low Pass Filter register calculations
+ *
+ * Note the largest count value of 0xffff corresponds to:
+ *     0xffff * 1000 / 108/2 MHz = 1,213,611.11... ns
+ * which fits in 21 bits, so we'll use unsigned int for time arguments.
+ */
+static inline u16 count_to_lpf_count(unsigned int d)
+{
+       if (d > FILTR_LPF)
+               d = FILTR_LPF;
+       else if (d < 4)
+               d = 0;
+       return (u16) d;
+}
+
+static inline u16 ns_to_lpf_count(unsigned int ns)
+{
+       return count_to_lpf_count(
+               DIV_ROUND_CLOSEST(CX25840_IR_REFCLK_FREQ / 1000000 * ns, 1000));
+}
+
+static inline unsigned int lpf_count_to_ns(unsigned int count)
+{
+       /* Duration of the Low Pass Filter rejection window in ns */
+       return DIV_ROUND_CLOSEST(count * 1000,
+                                CX25840_IR_REFCLK_FREQ / 1000000);
+}
+
+static inline unsigned int lpf_count_to_us(unsigned int count)
+{
+       /* Duration of the Low Pass Filter rejection window in us */
+       return DIV_ROUND_CLOSEST(count, CX25840_IR_REFCLK_FREQ / 1000000);
+}
+
+/*
+ * FIFO register pulse width count computations
+ */
+static u32 clock_divider_to_resolution(u16 divider)
+{
+       /*
+        * Resolution is the duration of 1 tick of the readable portion of
+        * of the pulse width counter as read from the FIFO.  The two lsb's are
+        * not readable, hence the << 2.  This function returns ns.
+        */
+       return DIV_ROUND_CLOSEST((1 << 2)  * ((u32) divider + 1) * 1000,
+                                CX25840_IR_REFCLK_FREQ / 1000000);
+}
+
+static u64 pulse_width_count_to_ns(u16 count, u16 divider)
+{
+       u64 n;
+       u32 rem;
+
+       /*
+        * The 2 lsb's of the pulse width timer count are not readable, hence
+        * the (count << 2) | 0x3
+        */
+       n = (((u64) count << 2) | 0x3) * (divider + 1) * 1000; /* millicycles */
+       rem = do_div(n, CX25840_IR_REFCLK_FREQ / 1000000);     /* / MHz => ns */
+       if (rem >= CX25840_IR_REFCLK_FREQ / 1000000 / 2)
+               n++;
+       return n;
+}
+
+#if 0
+/* Keep as we will need this for Transmit functionality */
+static u16 ns_to_pulse_width_count(u32 ns, u16 divider)
+{
+       u64 n;
+       u32 d;
+       u32 rem;
+
+       /*
+        * The 2 lsb's of the pulse width timer count are not accessible, hence
+        * the (1 << 2)
+        */
+       n = ((u64) ns) * CX25840_IR_REFCLK_FREQ / 1000000; /* millicycles */
+       d = (1 << 2) * ((u32) divider + 1) * 1000; /* millicycles/count */
+       rem = do_div(n, d);
+       if (rem >= d / 2)
+               n++;
+
+       if (n > FIFO_RXTX)
+               n = FIFO_RXTX;
+       else if (n == 0)
+               n = 1;
+       return (u16) n;
+}
+
+#endif
+static unsigned int pulse_width_count_to_us(u16 count, u16 divider)
+{
+       u64 n;
+       u32 rem;
+
+       /*
+        * The 2 lsb's of the pulse width timer count are not readable, hence
+        * the (count << 2) | 0x3
+        */
+       n = (((u64) count << 2) | 0x3) * (divider + 1);    /* cycles      */
+       rem = do_div(n, CX25840_IR_REFCLK_FREQ / 1000000); /* / MHz => us */
+       if (rem >= CX25840_IR_REFCLK_FREQ / 1000000 / 2)
+               n++;
+       return (unsigned int) n;
+}
+
+/*
+ * Pulse Clocks computations: Combined Pulse Width Count & Rx Clock Counts
+ *
+ * The total pulse clock count is an 18 bit pulse width timer count as the most
+ * significant part and (up to) 16 bit clock divider count as a modulus.
+ * When the Rx clock divider ticks down to 0, it increments the 18 bit pulse
+ * width timer count's least significant bit.
+ */
+static u64 ns_to_pulse_clocks(u32 ns)
+{
+       u64 clocks;
+       u32 rem;
+       clocks = CX25840_IR_REFCLK_FREQ / 1000000 * (u64) ns; /* millicycles  */
+       rem = do_div(clocks, 1000);                         /* /1000 = cycles */
+       if (rem >= 1000 / 2)
+               clocks++;
+       return clocks;
+}
+
+static u16 pulse_clocks_to_clock_divider(u64 count)
+{
+       do_div(count, (FIFO_RXTX << 2) | 0x3);
+
+       /* net result needs to be rounded down and decremented by 1 */
+       if (count > RXCLK_RCD + 1)
+               count = RXCLK_RCD;
+       else if (count < 2)
+               count = 1;
+       else
+               count--;
+       return (u16) count;
+}
+
+/*
+ * IR Control Register helpers
+ */
+enum tx_fifo_watermark {
+       TX_FIFO_HALF_EMPTY = 0,
+       TX_FIFO_EMPTY      = CNTRL_TIC,
+};
+
+enum rx_fifo_watermark {
+       RX_FIFO_HALF_FULL = 0,
+       RX_FIFO_NOT_EMPTY = CNTRL_RIC,
+};
+
+static inline void control_tx_irq_watermark(struct i2c_client *c,
+                                           enum tx_fifo_watermark level)
+{
+       cx25840_and_or4(c, CX25840_IR_CNTRL_REG, ~CNTRL_TIC, level);
+}
+
+static inline void control_rx_irq_watermark(struct i2c_client *c,
+                                           enum rx_fifo_watermark level)
+{
+       cx25840_and_or4(c, CX25840_IR_CNTRL_REG, ~CNTRL_RIC, level);
+}
+
+static inline void control_tx_enable(struct i2c_client *c, bool enable)
+{
+       cx25840_and_or4(c, CX25840_IR_CNTRL_REG, ~(CNTRL_TXE | CNTRL_TFE),
+                       enable ? (CNTRL_TXE | CNTRL_TFE) : 0);
+}
+
+static inline void control_rx_enable(struct i2c_client *c, bool enable)
+{
+       cx25840_and_or4(c, CX25840_IR_CNTRL_REG, ~(CNTRL_RXE | CNTRL_RFE),
+                       enable ? (CNTRL_RXE | CNTRL_RFE) : 0);
+}
+
+static inline void control_tx_modulation_enable(struct i2c_client *c,
+                                               bool enable)
+{
+       cx25840_and_or4(c, CX25840_IR_CNTRL_REG, ~CNTRL_MOD,
+                       enable ? CNTRL_MOD : 0);
+}
+
+static inline void control_rx_demodulation_enable(struct i2c_client *c,
+                                                 bool enable)
+{
+       cx25840_and_or4(c, CX25840_IR_CNTRL_REG, ~CNTRL_DMD,
+                       enable ? CNTRL_DMD : 0);
+}
+
+static inline void control_rx_s_edge_detection(struct i2c_client *c,
+                                              u32 edge_types)
+{
+       cx25840_and_or4(c, CX25840_IR_CNTRL_REG, ~CNTRL_EDG_BOTH,
+                       edge_types & CNTRL_EDG_BOTH);
+}
+
+static void control_rx_s_carrier_window(struct i2c_client *c,
+                                       unsigned int carrier,
+                                       unsigned int *carrier_range_low,
+                                       unsigned int *carrier_range_high)
+{
+       u32 v;
+       unsigned int c16 = carrier * 16;
+
+       if (*carrier_range_low < DIV_ROUND_CLOSEST(c16, 16 + 3)) {
+               v = CNTRL_WIN_3_4;
+               *carrier_range_low = DIV_ROUND_CLOSEST(c16, 16 + 4);
+       } else {
+               v = CNTRL_WIN_3_3;
+               *carrier_range_low = DIV_ROUND_CLOSEST(c16, 16 + 3);
+       }
+
+       if (*carrier_range_high > DIV_ROUND_CLOSEST(c16, 16 - 3)) {
+               v |= CNTRL_WIN_4_3;
+               *carrier_range_high = DIV_ROUND_CLOSEST(c16, 16 - 4);
+       } else {
+               v |= CNTRL_WIN_3_3;
+               *carrier_range_high = DIV_ROUND_CLOSEST(c16, 16 - 3);
+       }
+       cx25840_and_or4(c, CX25840_IR_CNTRL_REG, ~CNTRL_WIN, v);
+}
+
+static inline void control_tx_polarity_invert(struct i2c_client *c,
+                                             bool invert)
+{
+       cx25840_and_or4(c, CX25840_IR_CNTRL_REG, ~CNTRL_CPL,
+                       invert ? CNTRL_CPL : 0);
+}
+
+/*
+ * IR Rx & Tx Clock Register helpers
+ */
+static unsigned int txclk_tx_s_carrier(struct i2c_client *c,
+                                      unsigned int freq,
+                                      u16 *divider)
+{
+       *divider = carrier_freq_to_clock_divider(freq);
+       cx25840_write4(c, CX25840_IR_TXCLK_REG, *divider);
+       return clock_divider_to_carrier_freq(*divider);
+}
+
+static unsigned int rxclk_rx_s_carrier(struct i2c_client *c,
+                                      unsigned int freq,
+                                      u16 *divider)
+{
+       *divider = carrier_freq_to_clock_divider(freq);
+       cx25840_write4(c, CX25840_IR_RXCLK_REG, *divider);
+       return clock_divider_to_carrier_freq(*divider);
+}
+
+static u32 txclk_tx_s_max_pulse_width(struct i2c_client *c, u32 ns,
+                                     u16 *divider)
+{
+       u64 pulse_clocks;
+
+       if (ns > IR_MAX_DURATION)
+               ns = IR_MAX_DURATION;
+       pulse_clocks = ns_to_pulse_clocks(ns);
+       *divider = pulse_clocks_to_clock_divider(pulse_clocks);
+       cx25840_write4(c, CX25840_IR_TXCLK_REG, *divider);
+       return (u32) pulse_width_count_to_ns(FIFO_RXTX, *divider);
+}
+
+static u32 rxclk_rx_s_max_pulse_width(struct i2c_client *c, u32 ns,
+                                     u16 *divider)
+{
+       u64 pulse_clocks;
+
+       if (ns > IR_MAX_DURATION)
+               ns = IR_MAX_DURATION;
+       pulse_clocks = ns_to_pulse_clocks(ns);
+       *divider = pulse_clocks_to_clock_divider(pulse_clocks);
+       cx25840_write4(c, CX25840_IR_RXCLK_REG, *divider);
+       return (u32) pulse_width_count_to_ns(FIFO_RXTX, *divider);
+}
+
+/*
+ * IR Tx Carrier Duty Cycle register helpers
+ */
+static unsigned int cduty_tx_s_duty_cycle(struct i2c_client *c,
+                                         unsigned int duty_cycle)
+{
+       u32 n;
+       n = DIV_ROUND_CLOSEST(duty_cycle * 100, 625); /* 16ths of 100% */
+       if (n != 0)
+               n--;
+       if (n > 15)
+               n = 15;
+       cx25840_write4(c, CX25840_IR_CDUTY_REG, n);
+       return DIV_ROUND_CLOSEST((n + 1) * 100, 16);
+}
+
+/*
+ * IR Filter Register helpers
+ */
+static u32 filter_rx_s_min_width(struct i2c_client *c, u32 min_width_ns)
+{
+       u32 count = ns_to_lpf_count(min_width_ns);
+       cx25840_write4(c, CX25840_IR_FILTR_REG, count);
+       return lpf_count_to_ns(count);
+}
+
+/*
+ * IR IRQ Enable Register helpers
+ */
+static inline void irqenable_rx(struct v4l2_subdev *sd, u32 mask)
+{
+       struct cx25840_state *state = to_state(sd);
+
+       if (is_cx23885(state) || is_cx23887(state))
+               mask ^= IRQEN_MSK;
+       mask &= (IRQEN_RTE | IRQEN_ROE | IRQEN_RSE);
+       cx25840_and_or4(state->c, CX25840_IR_IRQEN_REG,
+                       ~(IRQEN_RTE | IRQEN_ROE | IRQEN_RSE), mask);
+}
+
+static inline void irqenable_tx(struct v4l2_subdev *sd, u32 mask)
+{
+       struct cx25840_state *state = to_state(sd);
+
+       if (is_cx23885(state) || is_cx23887(state))
+               mask ^= IRQEN_MSK;
+       mask &= IRQEN_TSE;
+       cx25840_and_or4(state->c, CX25840_IR_IRQEN_REG, ~IRQEN_TSE, mask);
+}
+
+/*
+ * V4L2 Subdevice IR Ops
+ */
+int cx25840_ir_irq_handler(struct v4l2_subdev *sd, u32 status, bool *handled)
+{
+       struct cx25840_state *state = to_state(sd);
+       struct cx25840_ir_state *ir_state = to_ir_state(sd);
+       struct i2c_client *c = NULL;
+       unsigned long flags;
+
+       union cx25840_ir_fifo_rec rx_data[FIFO_RX_DEPTH];
+       unsigned int i, j, k;
+       u32 events, v;
+       int tsr, rsr, rto, ror, tse, rse, rte, roe, kror;
+       u32 cntrl, irqen, stats;
+
+       *handled = false;
+       if (ir_state == NULL)
+               return -ENODEV;
+
+       c = ir_state->c;
+
+       /* Only support the IR controller for the CX2388[57] AV Core for now */
+       if (!(is_cx23885(state) || is_cx23887(state)))
+               return -ENODEV;
+
+       cntrl = cx25840_read4(c, CX25840_IR_CNTRL_REG);
+       irqen = cx25840_read4(c, CX25840_IR_IRQEN_REG);
+       if (is_cx23885(state) || is_cx23887(state))
+               irqen ^= IRQEN_MSK;
+       stats = cx25840_read4(c, CX25840_IR_STATS_REG);
+
+       tsr = stats & STATS_TSR; /* Tx FIFO Service Request */
+       rsr = stats & STATS_RSR; /* Rx FIFO Service Request */
+       rto = stats & STATS_RTO; /* Rx Pulse Width Timer Time Out */
+       ror = stats & STATS_ROR; /* Rx FIFO Over Run */
+
+       tse = irqen & IRQEN_TSE; /* Tx FIFO Service Request IRQ Enable */
+       rse = irqen & IRQEN_RSE; /* Rx FIFO Service Reuqest IRQ Enable */
+       rte = irqen & IRQEN_RTE; /* Rx Pulse Width Timer Time Out IRQ Enable */
+       roe = irqen & IRQEN_ROE; /* Rx FIFO Over Run IRQ Enable */
+
+       v4l2_dbg(2, ir_debug, sd, "IR IRQ Status:  %s %s %s %s %s %s\n",
+                tsr ? "tsr" : "   ", rsr ? "rsr" : "   ",
+                rto ? "rto" : "   ", ror ? "ror" : "   ",
+                stats & STATS_TBY ? "tby" : "   ",
+                stats & STATS_RBY ? "rby" : "   ");
+
+       v4l2_dbg(2, ir_debug, sd, "IR IRQ Enables: %s %s %s %s\n",
+                tse ? "tse" : "   ", rse ? "rse" : "   ",
+                rte ? "rte" : "   ", roe ? "roe" : "   ");
+
+       /*
+        * Transmitter interrupt service
+        */
+       if (tse && tsr) {
+               /*
+                * TODO:
+                * Check the watermark threshold setting
+                * Pull FIFO_TX_DEPTH or FIFO_TX_DEPTH/2 entries from tx_kfifo
+                * Push the data to the hardware FIFO.
+                * If there was nothing more to send in the tx_kfifo, disable
+                *      the TSR IRQ and notify the v4l2_device.
+                * If there was something in the tx_kfifo, check the tx_kfifo
+                *      level and notify the v4l2_device, if it is low.
+                */
+               /* For now, inhibit TSR interrupt until Tx is implemented */
+               irqenable_tx(sd, 0);
+               events = V4L2_SUBDEV_IR_TX_FIFO_SERVICE_REQ;
+               v4l2_subdev_notify(sd, V4L2_SUBDEV_IR_TX_NOTIFY, &events);
+               *handled = true;
+       }
+
+       /*
+        * Receiver interrupt service
+        */
+       kror = 0;
+       if ((rse && rsr) || (rte && rto)) {
+               /*
+                * Receive data on RSR to clear the STATS_RSR.
+                * Receive data on RTO, since we may not have yet hit the RSR
+                * watermark when we receive the RTO.
+                */
+               for (i = 0, v = FIFO_RX_NDV;
+                    (v & FIFO_RX_NDV) && !kror; i = 0) {
+                       for (j = 0;
+                            (v & FIFO_RX_NDV) && j < FIFO_RX_DEPTH; j++) {
+                               v = cx25840_read4(c, CX25840_IR_FIFO_REG);
+                               rx_data[i].hw_fifo_data = v & ~FIFO_RX_NDV;
+                               i++;
+                       }
+                       if (i == 0)
+                               break;
+                       j = i * sizeof(union cx25840_ir_fifo_rec);
+                       k = kfifo_in_locked(&ir_state->rx_kfifo,
+                                           (unsigned char *) rx_data, j,
+                                           &ir_state->rx_kfifo_lock);
+                       if (k != j)
+                               kror++; /* rx_kfifo over run */
+               }
+               *handled = true;
+       }
+
+       events = 0;
+       v = 0;
+       if (kror) {
+               events |= V4L2_SUBDEV_IR_RX_SW_FIFO_OVERRUN;
+               v4l2_err(sd, "IR receiver software FIFO overrun\n");
+       }
+       if (roe && ror) {
+               /*
+                * The RX FIFO Enable (CNTRL_RFE) must be toggled to clear
+                * the Rx FIFO Over Run status (STATS_ROR)
+                */
+               v |= CNTRL_RFE;
+               events |= V4L2_SUBDEV_IR_RX_HW_FIFO_OVERRUN;
+               v4l2_err(sd, "IR receiver hardware FIFO overrun\n");
+       }
+       if (rte && rto) {
+               /*
+                * The IR Receiver Enable (CNTRL_RXE) must be toggled to clear
+                * the Rx Pulse Width Timer Time Out (STATS_RTO)
+                */
+               v |= CNTRL_RXE;
+               events |= V4L2_SUBDEV_IR_RX_END_OF_RX_DETECTED;
+       }
+       if (v) {
+               /* Clear STATS_ROR & STATS_RTO as needed by reseting hardware */
+               cx25840_write4(c, CX25840_IR_CNTRL_REG, cntrl & ~v);
+               cx25840_write4(c, CX25840_IR_CNTRL_REG, cntrl);
+               *handled = true;
+       }
+       spin_lock_irqsave(&ir_state->rx_kfifo_lock, flags);
+       if (kfifo_len(&ir_state->rx_kfifo) >= CX25840_IR_RX_KFIFO_SIZE / 2)
+               events |= V4L2_SUBDEV_IR_RX_FIFO_SERVICE_REQ;
+       spin_unlock_irqrestore(&ir_state->rx_kfifo_lock, flags);
+
+       if (events)
+               v4l2_subdev_notify(sd, V4L2_SUBDEV_IR_RX_NOTIFY, &events);
+       return 0;
+}
+
+/* Receiver */
+static int cx25840_ir_rx_read(struct v4l2_subdev *sd, u8 *buf, size_t count,
+                             ssize_t *num)
+{
+       struct cx25840_ir_state *ir_state = to_ir_state(sd);
+       bool invert;
+       u16 divider;
+       unsigned int i, n;
+       union cx25840_ir_fifo_rec *p;
+       unsigned u, v, w;
+
+       if (ir_state == NULL)
+               return -ENODEV;
+
+       invert = (bool) atomic_read(&ir_state->rx_invert);
+       divider = (u16) atomic_read(&ir_state->rxclk_divider);
+
+       n = count / sizeof(union cx25840_ir_fifo_rec)
+               * sizeof(union cx25840_ir_fifo_rec);
+       if (n == 0) {
+               *num = 0;
+               return 0;
+       }
+
+       n = kfifo_out_locked(&ir_state->rx_kfifo, buf, n,
+                            &ir_state->rx_kfifo_lock);
+
+       n /= sizeof(union cx25840_ir_fifo_rec);
+       *num = n * sizeof(union cx25840_ir_fifo_rec);
+
+       for (p = (union cx25840_ir_fifo_rec *) buf, i = 0; i < n; p++, i++) {
+
+               if ((p->hw_fifo_data & FIFO_RXTX_RTO) == FIFO_RXTX_RTO) {
+                       /* Assume RTO was because of no IR light input */
+                       u = 0;
+                       w = 1;
+               } else {
+                       u = (p->hw_fifo_data & FIFO_RXTX_LVL) ? 1 : 0;
+                       if (invert)
+                               u = u ? 0 : 1;
+                       w = 0;
+               }
+
+               v = (unsigned) pulse_width_count_to_ns(
+                                 (u16) (p->hw_fifo_data & FIFO_RXTX), divider);
+               if (v > IR_MAX_DURATION)
+                       v = IR_MAX_DURATION;
+
+               init_ir_raw_event(&p->ir_core_data);
+               p->ir_core_data.pulse = u;
+               p->ir_core_data.duration = v;
+               p->ir_core_data.timeout = w;
+
+               v4l2_dbg(2, ir_debug, sd, "rx read: %10u ns  %s  %s\n",
+                        v, u ? "mark" : "space", w ? "(timed out)" : "");
+               if (w)
+                       v4l2_dbg(2, ir_debug, sd, "rx read: end of rx\n");
+       }
+       return 0;
+}
+
+static int cx25840_ir_rx_g_parameters(struct v4l2_subdev *sd,
+                                     struct v4l2_subdev_ir_parameters *p)
+{
+       struct cx25840_ir_state *ir_state = to_ir_state(sd);
+
+       if (ir_state == NULL)
+               return -ENODEV;
+
+       mutex_lock(&ir_state->rx_params_lock);
+       memcpy(p, &ir_state->rx_params,
+                                     sizeof(struct v4l2_subdev_ir_parameters));
+       mutex_unlock(&ir_state->rx_params_lock);
+       return 0;
+}
+
+static int cx25840_ir_rx_shutdown(struct v4l2_subdev *sd)
+{
+       struct cx25840_ir_state *ir_state = to_ir_state(sd);
+       struct i2c_client *c;
+
+       if (ir_state == NULL)
+               return -ENODEV;
+
+       c = ir_state->c;
+       mutex_lock(&ir_state->rx_params_lock);
+
+       /* Disable or slow down all IR Rx circuits and counters */
+       irqenable_rx(sd, 0);
+       control_rx_enable(c, false);
+       control_rx_demodulation_enable(c, false);
+       control_rx_s_edge_detection(c, CNTRL_EDG_NONE);
+       filter_rx_s_min_width(c, 0);
+       cx25840_write4(c, CX25840_IR_RXCLK_REG, RXCLK_RCD);
+
+       ir_state->rx_params.shutdown = true;
+
+       mutex_unlock(&ir_state->rx_params_lock);
+       return 0;
+}
+
+static int cx25840_ir_rx_s_parameters(struct v4l2_subdev *sd,
+                                     struct v4l2_subdev_ir_parameters *p)
+{
+       struct cx25840_ir_state *ir_state = to_ir_state(sd);
+       struct i2c_client *c;
+       struct v4l2_subdev_ir_parameters *o;
+       u16 rxclk_divider;
+
+       if (ir_state == NULL)
+               return -ENODEV;
+
+       if (p->shutdown)
+               return cx25840_ir_rx_shutdown(sd);
+
+       if (p->mode != V4L2_SUBDEV_IR_MODE_PULSE_WIDTH)
+               return -ENOSYS;
+
+       c = ir_state->c;
+       o = &ir_state->rx_params;
+
+       mutex_lock(&ir_state->rx_params_lock);
+
+       o->shutdown = p->shutdown;
+
+       p->mode = V4L2_SUBDEV_IR_MODE_PULSE_WIDTH;
+       o->mode = p->mode;
+
+       p->bytes_per_data_element = sizeof(union cx25840_ir_fifo_rec);
+       o->bytes_per_data_element = p->bytes_per_data_element;
+
+       /* Before we tweak the hardware, we have to disable the receiver */
+       irqenable_rx(sd, 0);
+       control_rx_enable(c, false);
+
+       control_rx_demodulation_enable(c, p->modulation);
+       o->modulation = p->modulation;
+
+       if (p->modulation) {
+               p->carrier_freq = rxclk_rx_s_carrier(c, p->carrier_freq,
+                                                    &rxclk_divider);
+
+               o->carrier_freq = p->carrier_freq;
+
+               p->duty_cycle = 50;
+               o->duty_cycle = p->duty_cycle;
+
+               control_rx_s_carrier_window(c, p->carrier_freq,
+                                           &p->carrier_range_lower,
+                                           &p->carrier_range_upper);
+               o->carrier_range_lower = p->carrier_range_lower;
+               o->carrier_range_upper = p->carrier_range_upper;
+
+               p->max_pulse_width =
+                       (u32) pulse_width_count_to_ns(FIFO_RXTX, rxclk_divider);
+       } else {
+               p->max_pulse_width =
+                           rxclk_rx_s_max_pulse_width(c, p->max_pulse_width,
+                                                      &rxclk_divider);
+       }
+       o->max_pulse_width = p->max_pulse_width;
+       atomic_set(&ir_state->rxclk_divider, rxclk_divider);
+
+       p->noise_filter_min_width =
+                           filter_rx_s_min_width(c, p->noise_filter_min_width);
+       o->noise_filter_min_width = p->noise_filter_min_width;
+
+       p->resolution = clock_divider_to_resolution(rxclk_divider);
+       o->resolution = p->resolution;
+
+       /* FIXME - make this dependent on resolution for better performance */
+       control_rx_irq_watermark(c, RX_FIFO_HALF_FULL);
+
+       control_rx_s_edge_detection(c, CNTRL_EDG_BOTH);
+
+       o->invert_level = p->invert_level;
+       atomic_set(&ir_state->rx_invert, p->invert_level);
+
+       o->interrupt_enable = p->interrupt_enable;
+       o->enable = p->enable;
+       if (p->enable) {
+               unsigned long flags;
+
+               spin_lock_irqsave(&ir_state->rx_kfifo_lock, flags);
+               kfifo_reset(&ir_state->rx_kfifo);
+               spin_unlock_irqrestore(&ir_state->rx_kfifo_lock, flags);
+               if (p->interrupt_enable)
+                       irqenable_rx(sd, IRQEN_RSE | IRQEN_RTE | IRQEN_ROE);
+               control_rx_enable(c, p->enable);
+       }
+
+       mutex_unlock(&ir_state->rx_params_lock);
+       return 0;
+}
+
+/* Transmitter */
+static int cx25840_ir_tx_write(struct v4l2_subdev *sd, u8 *buf, size_t count,
+                              ssize_t *num)
+{
+       struct cx25840_ir_state *ir_state = to_ir_state(sd);
+
+       if (ir_state == NULL)
+               return -ENODEV;
+
+#if 0
+       /*
+        * FIXME - the code below is an incomplete and untested sketch of what
+        * may need to be done.  The critical part is to get 4 (or 8) pulses
+        * from the tx_kfifo, or converted from ns to the proper units from the
+        * input, and push them off to the hardware Tx FIFO right away, if the
+        * HW TX fifo needs service.  The rest can be pushed to the tx_kfifo in
+        * a less critical timeframe.  Also watch out for overruning the
+        * tx_kfifo - don't let it happen and let the caller know not all his
+        * pulses were written.
+        */
+       u32 *ns_pulse = (u32 *) buf;
+       unsigned int n;
+       u32 fifo_pulse[FIFO_TX_DEPTH];
+       u32 mark;
+
+       /* Compute how much we can fit in the tx kfifo */
+       n = CX25840_IR_TX_KFIFO_SIZE - kfifo_len(ir_state->tx_kfifo);
+       n = min(n, (unsigned int) count);
+       n /= sizeof(u32);
+
+       /* FIXME - turn on Tx Fifo service interrupt
+        * check hardware fifo level, and other stuff
+        */
+       for (i = 0; i < n; ) {
+               for (j = 0; j < FIFO_TX_DEPTH / 2 && i < n; j++) {
+                       mark = ns_pulse[i] & LEVEL_MASK;
+                       fifo_pulse[j] = ns_to_pulse_width_count(
+                                        ns_pulse[i] &
+                                              ~LEVEL_MASK,
+                                        ir_state->txclk_divider);
+                       if (mark)
+                               fifo_pulse[j] &= FIFO_RXTX_LVL;
+                       i++;
+               }
+               kfifo_put(ir_state->tx_kfifo, (u8 *) fifo_pulse,
+                                                              j * sizeof(u32));
+       }
+       *num = n * sizeof(u32);
+#else
+       /* For now enable the Tx FIFO Service interrupt & pretend we did work */
+       irqenable_tx(sd, IRQEN_TSE);
+       *num = count;
+#endif
+       return 0;
+}
+
+static int cx25840_ir_tx_g_parameters(struct v4l2_subdev *sd,
+                                     struct v4l2_subdev_ir_parameters *p)
+{
+       struct cx25840_ir_state *ir_state = to_ir_state(sd);
+
+       if (ir_state == NULL)
+               return -ENODEV;
+
+       mutex_lock(&ir_state->tx_params_lock);
+       memcpy(p, &ir_state->tx_params,
+                                     sizeof(struct v4l2_subdev_ir_parameters));
+       mutex_unlock(&ir_state->tx_params_lock);
+       return 0;
+}
+
+static int cx25840_ir_tx_shutdown(struct v4l2_subdev *sd)
+{
+       struct cx25840_ir_state *ir_state = to_ir_state(sd);
+       struct i2c_client *c;
+
+       if (ir_state == NULL)
+               return -ENODEV;
+
+       c = ir_state->c;
+       mutex_lock(&ir_state->tx_params_lock);
+
+       /* Disable or slow down all IR Tx circuits and counters */
+       irqenable_tx(sd, 0);
+       control_tx_enable(c, false);
+       control_tx_modulation_enable(c, false);
+       cx25840_write4(c, CX25840_IR_TXCLK_REG, TXCLK_TCD);
+
+       ir_state->tx_params.shutdown = true;
+
+       mutex_unlock(&ir_state->tx_params_lock);
+       return 0;
+}
+
+static int cx25840_ir_tx_s_parameters(struct v4l2_subdev *sd,
+                                     struct v4l2_subdev_ir_parameters *p)
+{
+       struct cx25840_ir_state *ir_state = to_ir_state(sd);
+       struct i2c_client *c;
+       struct v4l2_subdev_ir_parameters *o;
+       u16 txclk_divider;
+
+       if (ir_state == NULL)
+               return -ENODEV;
+
+       if (p->shutdown)
+               return cx25840_ir_tx_shutdown(sd);
+
+       if (p->mode != V4L2_SUBDEV_IR_MODE_PULSE_WIDTH)
+               return -ENOSYS;
+
+       c = ir_state->c;
+       o = &ir_state->tx_params;
+       mutex_lock(&ir_state->tx_params_lock);
+
+       o->shutdown = p->shutdown;
+
+       p->mode = V4L2_SUBDEV_IR_MODE_PULSE_WIDTH;
+       o->mode = p->mode;
+
+       p->bytes_per_data_element = sizeof(union cx25840_ir_fifo_rec);
+       o->bytes_per_data_element = p->bytes_per_data_element;
+
+       /* Before we tweak the hardware, we have to disable the transmitter */
+       irqenable_tx(sd, 0);
+       control_tx_enable(c, false);
+
+       control_tx_modulation_enable(c, p->modulation);
+       o->modulation = p->modulation;
+
+       if (p->modulation) {
+               p->carrier_freq = txclk_tx_s_carrier(c, p->carrier_freq,
+                                                    &txclk_divider);
+               o->carrier_freq = p->carrier_freq;
+
+               p->duty_cycle = cduty_tx_s_duty_cycle(c, p->duty_cycle);
+               o->duty_cycle = p->duty_cycle;
+
+               p->max_pulse_width =
+                       (u32) pulse_width_count_to_ns(FIFO_RXTX, txclk_divider);
+       } else {
+               p->max_pulse_width =
+                           txclk_tx_s_max_pulse_width(c, p->max_pulse_width,
+                                                      &txclk_divider);
+       }
+       o->max_pulse_width = p->max_pulse_width;
+       atomic_set(&ir_state->txclk_divider, txclk_divider);
+
+       p->resolution = clock_divider_to_resolution(txclk_divider);
+       o->resolution = p->resolution;
+
+       /* FIXME - make this dependent on resolution for better performance */
+       control_tx_irq_watermark(c, TX_FIFO_HALF_EMPTY);
+
+       control_tx_polarity_invert(c, p->invert_carrier_sense);
+       o->invert_carrier_sense = p->invert_carrier_sense;
+
+       /*
+        * FIXME: we don't have hardware help for IO pin level inversion
+        * here like we have on the CX23888.
+        * Act on this with some mix of logical inversion of data levels,
+        * carrier polarity, and carrier duty cycle.
+        */
+       o->invert_level = p->invert_level;
+
+       o->interrupt_enable = p->interrupt_enable;
+       o->enable = p->enable;
+       if (p->enable) {
+               /* reset tx_fifo here */
+               if (p->interrupt_enable)
+                       irqenable_tx(sd, IRQEN_TSE);
+               control_tx_enable(c, p->enable);
+       }
+
+       mutex_unlock(&ir_state->tx_params_lock);
+       return 0;
+}
+
+
+/*
+ * V4L2 Subdevice Core Ops support
+ */
+int cx25840_ir_log_status(struct v4l2_subdev *sd)
+{
+       struct cx25840_state *state = to_state(sd);
+       struct i2c_client *c = state->c;
+       char *s;
+       int i, j;
+       u32 cntrl, txclk, rxclk, cduty, stats, irqen, filtr;
+
+       /* The CX23888 chip doesn't have an IR controller on the A/V core */
+       if (is_cx23888(state))
+               return 0;
+
+       cntrl = cx25840_read4(c, CX25840_IR_CNTRL_REG);
+       txclk = cx25840_read4(c, CX25840_IR_TXCLK_REG) & TXCLK_TCD;
+       rxclk = cx25840_read4(c, CX25840_IR_RXCLK_REG) & RXCLK_RCD;
+       cduty = cx25840_read4(c, CX25840_IR_CDUTY_REG) & CDUTY_CDC;
+       stats = cx25840_read4(c, CX25840_IR_STATS_REG);
+       irqen = cx25840_read4(c, CX25840_IR_IRQEN_REG);
+       if (is_cx23885(state) || is_cx23887(state))
+               irqen ^= IRQEN_MSK;
+       filtr = cx25840_read4(c, CX25840_IR_FILTR_REG) & FILTR_LPF;
+
+       v4l2_info(sd, "IR Receiver:\n");
+       v4l2_info(sd, "\tEnabled:                           %s\n",
+                 cntrl & CNTRL_RXE ? "yes" : "no");
+       v4l2_info(sd, "\tDemodulation from a carrier:       %s\n",
+                 cntrl & CNTRL_DMD ? "enabled" : "disabled");
+       v4l2_info(sd, "\tFIFO:                              %s\n",
+                 cntrl & CNTRL_RFE ? "enabled" : "disabled");
+       switch (cntrl & CNTRL_EDG) {
+       case CNTRL_EDG_NONE:
+               s = "disabled";
+               break;
+       case CNTRL_EDG_FALL:
+               s = "falling edge";
+               break;
+       case CNTRL_EDG_RISE:
+               s = "rising edge";
+               break;
+       case CNTRL_EDG_BOTH:
+               s = "rising & falling edges";
+               break;
+       default:
+               s = "??? edge";
+               break;
+       }
+       v4l2_info(sd, "\tPulse timers' start/stop trigger:  %s\n", s);
+       v4l2_info(sd, "\tFIFO data on pulse timer overflow: %s\n",
+                 cntrl & CNTRL_R ? "not loaded" : "overflow marker");
+       v4l2_info(sd, "\tFIFO interrupt watermark:          %s\n",
+                 cntrl & CNTRL_RIC ? "not empty" : "half full or greater");
+       v4l2_info(sd, "\tLoopback mode:                     %s\n",
+                 cntrl & CNTRL_LBM ? "loopback active" : "normal receive");
+       if (cntrl & CNTRL_DMD) {
+               v4l2_info(sd, "\tExpected carrier (16 clocks):      %u Hz\n",
+                         clock_divider_to_carrier_freq(rxclk));
+               switch (cntrl & CNTRL_WIN) {
+               case CNTRL_WIN_3_3:
+                       i = 3;
+                       j = 3;
+                       break;
+               case CNTRL_WIN_4_3:
+                       i = 4;
+                       j = 3;
+                       break;
+               case CNTRL_WIN_3_4:
+                       i = 3;
+                       j = 4;
+                       break;
+               case CNTRL_WIN_4_4:
+                       i = 4;
+                       j = 4;
+                       break;
+               default:
+                       i = 0;
+                       j = 0;
+                       break;
+               }
+               v4l2_info(sd, "\tNext carrier edge window:          16 clocks "
+                         "-%1d/+%1d, %u to %u Hz\n", i, j,
+                         clock_divider_to_freq(rxclk, 16 + j),
+                         clock_divider_to_freq(rxclk, 16 - i));
+       }
+       v4l2_info(sd, "\tMax measurable pulse width:        %u us, %llu ns\n",
+                 pulse_width_count_to_us(FIFO_RXTX, rxclk),
+                 pulse_width_count_to_ns(FIFO_RXTX, rxclk));
+       v4l2_info(sd, "\tLow pass filter:                   %s\n",
+                 filtr ? "enabled" : "disabled");
+       if (filtr)
+               v4l2_info(sd, "\tMin acceptable pulse width (LPF):  %u us, "
+                         "%u ns\n",
+                         lpf_count_to_us(filtr),
+                         lpf_count_to_ns(filtr));
+       v4l2_info(sd, "\tPulse width timer timed-out:       %s\n",
+                 stats & STATS_RTO ? "yes" : "no");
+       v4l2_info(sd, "\tPulse width timer time-out intr:   %s\n",
+                 irqen & IRQEN_RTE ? "enabled" : "disabled");
+       v4l2_info(sd, "\tFIFO overrun:                      %s\n",
+                 stats & STATS_ROR ? "yes" : "no");
+       v4l2_info(sd, "\tFIFO overrun interrupt:            %s\n",
+                 irqen & IRQEN_ROE ? "enabled" : "disabled");
+       v4l2_info(sd, "\tBusy:                              %s\n",
+                 stats & STATS_RBY ? "yes" : "no");
+       v4l2_info(sd, "\tFIFO service requested:            %s\n",
+                 stats & STATS_RSR ? "yes" : "no");
+       v4l2_info(sd, "\tFIFO service request interrupt:    %s\n",
+                 irqen & IRQEN_RSE ? "enabled" : "disabled");
+
+       v4l2_info(sd, "IR Transmitter:\n");
+       v4l2_info(sd, "\tEnabled:                           %s\n",
+                 cntrl & CNTRL_TXE ? "yes" : "no");
+       v4l2_info(sd, "\tModulation onto a carrier:         %s\n",
+                 cntrl & CNTRL_MOD ? "enabled" : "disabled");
+       v4l2_info(sd, "\tFIFO:                              %s\n",
+                 cntrl & CNTRL_TFE ? "enabled" : "disabled");
+       v4l2_info(sd, "\tFIFO interrupt watermark:          %s\n",
+                 cntrl & CNTRL_TIC ? "not empty" : "half full or less");
+       v4l2_info(sd, "\tCarrier polarity:                  %s\n",
+                 cntrl & CNTRL_CPL ? "space:burst mark:noburst"
+                                   : "space:noburst mark:burst");
+       if (cntrl & CNTRL_MOD) {
+               v4l2_info(sd, "\tCarrier (16 clocks):               %u Hz\n",
+                         clock_divider_to_carrier_freq(txclk));
+               v4l2_info(sd, "\tCarrier duty cycle:                %2u/16\n",
+                         cduty + 1);
+       }
+       v4l2_info(sd, "\tMax pulse width:                   %u us, %llu ns\n",
+                 pulse_width_count_to_us(FIFO_RXTX, txclk),
+                 pulse_width_count_to_ns(FIFO_RXTX, txclk));
+       v4l2_info(sd, "\tBusy:                              %s\n",
+                 stats & STATS_TBY ? "yes" : "no");
+       v4l2_info(sd, "\tFIFO service requested:            %s\n",
+                 stats & STATS_TSR ? "yes" : "no");
+       v4l2_info(sd, "\tFIFO service request interrupt:    %s\n",
+                 irqen & IRQEN_TSE ? "enabled" : "disabled");
+
+       return 0;
+}
+
+
+const struct v4l2_subdev_ir_ops cx25840_ir_ops = {
+       .rx_read = cx25840_ir_rx_read,
+       .rx_g_parameters = cx25840_ir_rx_g_parameters,
+       .rx_s_parameters = cx25840_ir_rx_s_parameters,
+
+       .tx_write = cx25840_ir_tx_write,
+       .tx_g_parameters = cx25840_ir_tx_g_parameters,
+       .tx_s_parameters = cx25840_ir_tx_s_parameters,
+};
+
+
+static const struct v4l2_subdev_ir_parameters default_rx_params = {
+       .bytes_per_data_element = sizeof(union cx25840_ir_fifo_rec),
+       .mode = V4L2_SUBDEV_IR_MODE_PULSE_WIDTH,
+
+       .enable = false,
+       .interrupt_enable = false,
+       .shutdown = true,
+
+       .modulation = true,
+       .carrier_freq = 36000, /* 36 kHz - RC-5, and RC-6 carrier */
+
+       /* RC-5: 666,667 ns = 1/36 kHz * 32 cycles * 1 mark * 0.75 */
+       /* RC-6: 333,333 ns = 1/36 kHz * 16 cycles * 1 mark * 0.75 */
+       .noise_filter_min_width = 333333, /* ns */
+       .carrier_range_lower = 35000,
+       .carrier_range_upper = 37000,
+       .invert_level = false,
+};
+
+static const struct v4l2_subdev_ir_parameters default_tx_params = {
+       .bytes_per_data_element = sizeof(union cx25840_ir_fifo_rec),
+       .mode = V4L2_SUBDEV_IR_MODE_PULSE_WIDTH,
+
+       .enable = false,
+       .interrupt_enable = false,
+       .shutdown = true,
+
+       .modulation = true,
+       .carrier_freq = 36000, /* 36 kHz - RC-5 carrier */
+       .duty_cycle = 25,      /* 25 %   - RC-5 carrier */
+       .invert_level = false,
+       .invert_carrier_sense = false,
+};
+
+int cx25840_ir_probe(struct v4l2_subdev *sd)
+{
+       struct cx25840_state *state = to_state(sd);
+       struct cx25840_ir_state *ir_state;
+       struct v4l2_subdev_ir_parameters default_params;
+
+       /* Only init the IR controller for the CX2388[57] AV Core for now */
+       if (!(is_cx23885(state) || is_cx23887(state)))
+               return 0;
+
+       ir_state = devm_kzalloc(&state->c->dev, sizeof(*ir_state), GFP_KERNEL);
+       if (ir_state == NULL)
+               return -ENOMEM;
+
+       spin_lock_init(&ir_state->rx_kfifo_lock);
+       if (kfifo_alloc(&ir_state->rx_kfifo,
+                       CX25840_IR_RX_KFIFO_SIZE, GFP_KERNEL))
+               return -ENOMEM;
+
+       ir_state->c = state->c;
+       state->ir_state = ir_state;
+
+       /* Ensure no interrupts arrive yet */
+       if (is_cx23885(state) || is_cx23887(state))
+               cx25840_write4(ir_state->c, CX25840_IR_IRQEN_REG, IRQEN_MSK);
+       else
+               cx25840_write4(ir_state->c, CX25840_IR_IRQEN_REG, 0);
+
+       mutex_init(&ir_state->rx_params_lock);
+       default_params = default_rx_params;
+       v4l2_subdev_call(sd, ir, rx_s_parameters, &default_params);
+
+       mutex_init(&ir_state->tx_params_lock);
+       default_params = default_tx_params;
+       v4l2_subdev_call(sd, ir, tx_s_parameters, &default_params);
+
+       return 0;
+}
+
+int cx25840_ir_remove(struct v4l2_subdev *sd)
+{
+       struct cx25840_state *state = to_state(sd);
+       struct cx25840_ir_state *ir_state = to_ir_state(sd);
+
+       if (ir_state == NULL)
+               return -ENODEV;
+
+       cx25840_ir_rx_shutdown(sd);
+       cx25840_ir_tx_shutdown(sd);
+
+       kfifo_free(&ir_state->rx_kfifo);
+       state->ir_state = NULL;
+       return 0;
+}