--- /dev/null
+/*
+ * SuperH Mobile I2C Controller
+ *
+ * Copyright (C) 2014 Wolfram Sang <wsa@sang-engineering.com>
+ *
+ * Copyright (C) 2008 Magnus Damm
+ *
+ * Portions of the code based on out-of-tree driver i2c-sh7343.c
+ * Copyright (c) 2006 Carlos Munoz <carlos@kenati.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; either version 2 of the License
+ *
+ * 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/clk.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/i2c/i2c-sh_mobile.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+
+/* Transmit operation: */
+/* */
+/* 0 byte transmit */
+/* BUS: S A8 ACK P(*) */
+/* IRQ: DTE WAIT */
+/* ICIC: */
+/* ICCR: 0x94 0x90 */
+/* ICDR: A8 */
+/* */
+/* 1 byte transmit */
+/* BUS: S A8 ACK D8(1) ACK P(*) */
+/* IRQ: DTE WAIT WAIT */
+/* ICIC: -DTE */
+/* ICCR: 0x94 0x90 */
+/* ICDR: A8 D8(1) */
+/* */
+/* 2 byte transmit */
+/* BUS: S A8 ACK D8(1) ACK D8(2) ACK P(*) */
+/* IRQ: DTE WAIT WAIT WAIT */
+/* ICIC: -DTE */
+/* ICCR: 0x94 0x90 */
+/* ICDR: A8 D8(1) D8(2) */
+/* */
+/* 3 bytes or more, +---------+ gets repeated */
+/* */
+/* */
+/* Receive operation: */
+/* */
+/* 0 byte receive - not supported since slave may hold SDA low */
+/* */
+/* 1 byte receive [TX] | [RX] */
+/* BUS: S A8 ACK | D8(1) ACK P(*) */
+/* IRQ: DTE WAIT | WAIT DTE */
+/* ICIC: -DTE | +DTE */
+/* ICCR: 0x94 0x81 | 0xc0 */
+/* ICDR: A8 | D8(1) */
+/* */
+/* 2 byte receive [TX]| [RX] */
+/* BUS: S A8 ACK | D8(1) ACK D8(2) ACK P(*) */
+/* IRQ: DTE WAIT | WAIT WAIT DTE */
+/* ICIC: -DTE | +DTE */
+/* ICCR: 0x94 0x81 | 0xc0 */
+/* ICDR: A8 | D8(1) D8(2) */
+/* */
+/* 3 byte receive [TX] | [RX] (*) */
+/* BUS: S A8 ACK | D8(1) ACK D8(2) ACK D8(3) ACK P */
+/* IRQ: DTE WAIT | WAIT WAIT WAIT DTE */
+/* ICIC: -DTE | +DTE */
+/* ICCR: 0x94 0x81 | 0xc0 */
+/* ICDR: A8 | D8(1) D8(2) D8(3) */
+/* */
+/* 4 bytes or more, this part is repeated +---------+ */
+/* */
+/* */
+/* Interrupt order and BUSY flag */
+/* ___ _ */
+/* SDA ___\___XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXAAAAAAAAA___/ */
+/* SCL \_/1\_/2\_/3\_/4\_/5\_/6\_/7\_/8\___/9\_____/ */
+/* */
+/* S D7 D6 D5 D4 D3 D2 D1 D0 P(*) */
+/* ___ */
+/* WAIT IRQ ________________________________/ \___________ */
+/* TACK IRQ ____________________________________/ \_______ */
+/* DTE IRQ __________________________________________/ \_ */
+/* AL IRQ XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX */
+/* _______________________________________________ */
+/* BUSY __/ \_ */
+/* */
+/* (*) The STOP condition is only sent by the master at the end of the last */
+/* I2C message or if the I2C_M_STOP flag is set. Similarly, the BUSY bit is */
+/* only cleared after the STOP condition, so, between messages we have to */
+/* poll for the DTE bit. */
+/* */
+
+enum sh_mobile_i2c_op {
+ OP_START = 0,
+ OP_TX_FIRST,
+ OP_TX,
+ OP_TX_STOP,
+ OP_TX_STOP_DATA,
+ OP_TX_TO_RX,
+ OP_RX,
+ OP_RX_STOP,
+ OP_RX_STOP_DATA,
+};
+
+struct sh_mobile_i2c_data {
+ struct device *dev;
+ void __iomem *reg;
+ struct i2c_adapter adap;
+ unsigned long bus_speed;
+ unsigned int clks_per_count;
+ struct clk *clk;
+ u_int8_t icic;
+ u_int8_t flags;
+ u_int16_t iccl;
+ u_int16_t icch;
+
+ spinlock_t lock;
+ wait_queue_head_t wait;
+ struct i2c_msg *msg;
+ int pos;
+ int sr;
+ bool send_stop;
+ bool stop_after_dma;
+
+ struct resource *res;
+ struct dma_chan *dma_tx;
+ struct dma_chan *dma_rx;
+ struct scatterlist sg;
+ enum dma_data_direction dma_direction;
+};
+
+struct sh_mobile_dt_config {
+ int clks_per_count;
+};
+
+#define IIC_FLAG_HAS_ICIC67 (1 << 0)
+
+#define STANDARD_MODE 100000
+#define FAST_MODE 400000
+
+/* Register offsets */
+#define ICDR 0x00
+#define ICCR 0x04
+#define ICSR 0x08
+#define ICIC 0x0c
+#define ICCL 0x10
+#define ICCH 0x14
+
+/* Register bits */
+#define ICCR_ICE 0x80
+#define ICCR_RACK 0x40
+#define ICCR_TRS 0x10
+#define ICCR_BBSY 0x04
+#define ICCR_SCP 0x01
+
+#define ICSR_SCLM 0x80
+#define ICSR_SDAM 0x40
+#define SW_DONE 0x20
+#define ICSR_BUSY 0x10
+#define ICSR_AL 0x08
+#define ICSR_TACK 0x04
+#define ICSR_WAIT 0x02
+#define ICSR_DTE 0x01
+
+#define ICIC_ICCLB8 0x80
+#define ICIC_ICCHB8 0x40
+#define ICIC_TDMAE 0x20
+#define ICIC_RDMAE 0x10
+#define ICIC_ALE 0x08
+#define ICIC_TACKE 0x04
+#define ICIC_WAITE 0x02
+#define ICIC_DTEE 0x01
+
+static void iic_wr(struct sh_mobile_i2c_data *pd, int offs, unsigned char data)
+{
+ if (offs == ICIC)
+ data |= pd->icic;
+
+ iowrite8(data, pd->reg + offs);
+}
+
+static unsigned char iic_rd(struct sh_mobile_i2c_data *pd, int offs)
+{
+ return ioread8(pd->reg + offs);
+}
+
+static void iic_set_clr(struct sh_mobile_i2c_data *pd, int offs,
+ unsigned char set, unsigned char clr)
+{
+ iic_wr(pd, offs, (iic_rd(pd, offs) | set) & ~clr);
+}
+
+static u32 sh_mobile_i2c_iccl(unsigned long count_khz, u32 tLOW, u32 tf)
+{
+ /*
+ * Conditional expression:
+ * ICCL >= COUNT_CLK * (tLOW + tf)
+ *
+ * SH-Mobile IIC hardware starts counting the LOW period of
+ * the SCL signal (tLOW) as soon as it pulls the SCL line.
+ * In order to meet the tLOW timing spec, we need to take into
+ * account the fall time of SCL signal (tf). Default tf value
+ * should be 0.3 us, for safety.
+ */
+ return (((count_khz * (tLOW + tf)) + 5000) / 10000);
+}
+
+static u32 sh_mobile_i2c_icch(unsigned long count_khz, u32 tHIGH, u32 tf)
+{
+ /*
+ * Conditional expression:
+ * ICCH >= COUNT_CLK * (tHIGH + tf)
+ *
+ * SH-Mobile IIC hardware is aware of SCL transition period 'tr',
+ * and can ignore it. SH-Mobile IIC controller starts counting
+ * the HIGH period of the SCL signal (tHIGH) after the SCL input
+ * voltage increases at VIH.
+ *
+ * Afterward it turned out calculating ICCH using only tHIGH spec
+ * will result in violation of the tHD;STA timing spec. We need
+ * to take into account the fall time of SDA signal (tf) at START
+ * condition, in order to meet both tHIGH and tHD;STA specs.
+ */
+ return (((count_khz * (tHIGH + tf)) + 5000) / 10000);
+}
+
+static int sh_mobile_i2c_init(struct sh_mobile_i2c_data *pd)
+{
+ unsigned long i2c_clk_khz;
+ u32 tHIGH, tLOW, tf;
+ uint16_t max_val;
+
+ /* Get clock rate after clock is enabled */
+ clk_prepare_enable(pd->clk);
+ i2c_clk_khz = clk_get_rate(pd->clk) / 1000;
+ clk_disable_unprepare(pd->clk);
+ i2c_clk_khz /= pd->clks_per_count;
+
+ if (pd->bus_speed == STANDARD_MODE) {
+ tLOW = 47; /* tLOW = 4.7 us */
+ tHIGH = 40; /* tHD;STA = tHIGH = 4.0 us */
+ tf = 3; /* tf = 0.3 us */
+ } else if (pd->bus_speed == FAST_MODE) {
+ tLOW = 13; /* tLOW = 1.3 us */
+ tHIGH = 6; /* tHD;STA = tHIGH = 0.6 us */
+ tf = 3; /* tf = 0.3 us */
+ } else {
+ dev_err(pd->dev, "unrecognized bus speed %lu Hz\n",
+ pd->bus_speed);
+ return -EINVAL;
+ }
+
+ pd->iccl = sh_mobile_i2c_iccl(i2c_clk_khz, tLOW, tf);
+ pd->icch = sh_mobile_i2c_icch(i2c_clk_khz, tHIGH, tf);
+
+ max_val = pd->flags & IIC_FLAG_HAS_ICIC67 ? 0x1ff : 0xff;
+ if (pd->iccl > max_val || pd->icch > max_val) {
+ dev_err(pd->dev, "timing values out of range: L/H=0x%x/0x%x\n",
+ pd->iccl, pd->icch);
+ return -EINVAL;
+ }
+
+ /* one more bit of ICCL in ICIC */
+ if (pd->iccl & 0x100)
+ pd->icic |= ICIC_ICCLB8;
+ else
+ pd->icic &= ~ICIC_ICCLB8;
+
+ /* one more bit of ICCH in ICIC */
+ if (pd->icch & 0x100)
+ pd->icic |= ICIC_ICCHB8;
+ else
+ pd->icic &= ~ICIC_ICCHB8;
+
+ dev_dbg(pd->dev, "timing values: L/H=0x%x/0x%x\n", pd->iccl, pd->icch);
+ return 0;
+}
+
+static void activate_ch(struct sh_mobile_i2c_data *pd)
+{
+ /* Wake up device and enable clock */
+ pm_runtime_get_sync(pd->dev);
+ clk_prepare_enable(pd->clk);
+
+ /* Enable channel and configure rx ack */
+ iic_set_clr(pd, ICCR, ICCR_ICE, 0);
+
+ /* Mask all interrupts */
+ iic_wr(pd, ICIC, 0);
+
+ /* Set the clock */
+ iic_wr(pd, ICCL, pd->iccl & 0xff);
+ iic_wr(pd, ICCH, pd->icch & 0xff);
+}
+
+static void deactivate_ch(struct sh_mobile_i2c_data *pd)
+{
+ /* Clear/disable interrupts */
+ iic_wr(pd, ICSR, 0);
+ iic_wr(pd, ICIC, 0);
+
+ /* Disable channel */
+ iic_set_clr(pd, ICCR, 0, ICCR_ICE);
+
+ /* Disable clock and mark device as idle */
+ clk_disable_unprepare(pd->clk);
+ pm_runtime_put_sync(pd->dev);
+}
+
+static unsigned char i2c_op(struct sh_mobile_i2c_data *pd,
+ enum sh_mobile_i2c_op op, unsigned char data)
+{
+ unsigned char ret = 0;
+ unsigned long flags;
+
+ dev_dbg(pd->dev, "op %d, data in 0x%02x\n", op, data);
+
+ spin_lock_irqsave(&pd->lock, flags);
+
+ switch (op) {
+ case OP_START: /* issue start and trigger DTE interrupt */
+ iic_wr(pd, ICCR, ICCR_ICE | ICCR_TRS | ICCR_BBSY);
+ break;
+ case OP_TX_FIRST: /* disable DTE interrupt and write data */
+ iic_wr(pd, ICIC, ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
+ iic_wr(pd, ICDR, data);
+ break;
+ case OP_TX: /* write data */
+ iic_wr(pd, ICDR, data);
+ break;
+ case OP_TX_STOP_DATA: /* write data and issue a stop afterwards */
+ iic_wr(pd, ICDR, data);
+ /* fallthrough */
+ case OP_TX_STOP: /* issue a stop */
+ iic_wr(pd, ICCR, pd->send_stop ? ICCR_ICE | ICCR_TRS
+ : ICCR_ICE | ICCR_TRS | ICCR_BBSY);
+ break;
+ case OP_TX_TO_RX: /* select read mode */
+ iic_wr(pd, ICCR, ICCR_ICE | ICCR_SCP);
+ break;
+ case OP_RX: /* just read data */
+ ret = iic_rd(pd, ICDR);
+ break;
+ case OP_RX_STOP: /* enable DTE interrupt, issue stop */
+ iic_wr(pd, ICIC,
+ ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
+ iic_wr(pd, ICCR, ICCR_ICE | ICCR_RACK);
+ break;
+ case OP_RX_STOP_DATA: /* enable DTE interrupt, read data, issue stop */
+ iic_wr(pd, ICIC,
+ ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
+ ret = iic_rd(pd, ICDR);
+ iic_wr(pd, ICCR, ICCR_ICE | ICCR_RACK);
+ break;
+ }
+
+ spin_unlock_irqrestore(&pd->lock, flags);
+
+ dev_dbg(pd->dev, "op %d, data out 0x%02x\n", op, ret);
+ return ret;
+}
+
+static bool sh_mobile_i2c_is_first_byte(struct sh_mobile_i2c_data *pd)
+{
+ return pd->pos == -1;
+}
+
+static bool sh_mobile_i2c_is_last_byte(struct sh_mobile_i2c_data *pd)
+{
+ return pd->pos == pd->msg->len - 1;
+}
+
+static void sh_mobile_i2c_get_data(struct sh_mobile_i2c_data *pd,
+ unsigned char *buf)
+{
+ switch (pd->pos) {
+ case -1:
+ *buf = (pd->msg->addr & 0x7f) << 1;
+ *buf |= (pd->msg->flags & I2C_M_RD) ? 1 : 0;
+ break;
+ default:
+ *buf = pd->msg->buf[pd->pos];
+ }
+}
+
+static int sh_mobile_i2c_isr_tx(struct sh_mobile_i2c_data *pd)
+{
+ unsigned char data;
+
+ if (pd->pos == pd->msg->len) {
+ /* Send stop if we haven't yet (DMA case) */
+ if (pd->send_stop && pd->stop_after_dma)
+ i2c_op(pd, OP_TX_STOP, 0);
+ return 1;
+ }
+
+ sh_mobile_i2c_get_data(pd, &data);
+
+ if (sh_mobile_i2c_is_last_byte(pd))
+ i2c_op(pd, OP_TX_STOP_DATA, data);
+ else if (sh_mobile_i2c_is_first_byte(pd))
+ i2c_op(pd, OP_TX_FIRST, data);
+ else
+ i2c_op(pd, OP_TX, data);
+
+ pd->pos++;
+ return 0;
+}
+
+static int sh_mobile_i2c_isr_rx(struct sh_mobile_i2c_data *pd)
+{
+ unsigned char data;
+ int real_pos;
+
+ do {
+ if (pd->pos <= -1) {
+ sh_mobile_i2c_get_data(pd, &data);
+
+ if (sh_mobile_i2c_is_first_byte(pd))
+ i2c_op(pd, OP_TX_FIRST, data);
+ else
+ i2c_op(pd, OP_TX, data);
+ break;
+ }
+
+ if (pd->pos == 0) {
+ i2c_op(pd, OP_TX_TO_RX, 0);
+ break;
+ }
+
+ real_pos = pd->pos - 2;
+
+ if (pd->pos == pd->msg->len) {
+ if (pd->stop_after_dma) {
+ /* Simulate PIO end condition after DMA transfer */
+ i2c_op(pd, OP_RX_STOP, 0);
+ pd->pos++;
+ break;
+ }
+
+ if (real_pos < 0) {
+ i2c_op(pd, OP_RX_STOP, 0);
+ break;
+ }
+ data = i2c_op(pd, OP_RX_STOP_DATA, 0);
+ } else
+ data = i2c_op(pd, OP_RX, 0);
+
+ if (real_pos >= 0)
+ pd->msg->buf[real_pos] = data;
+ } while (0);
+
+ pd->pos++;
+ return pd->pos == (pd->msg->len + 2);
+}
+
+static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id)
+{
+ struct sh_mobile_i2c_data *pd = dev_id;
+ unsigned char sr;
+ int wakeup = 0;
+
+ sr = iic_rd(pd, ICSR);
+ pd->sr |= sr; /* remember state */
+
+ dev_dbg(pd->dev, "i2c_isr 0x%02x 0x%02x %s %d %d!\n", sr, pd->sr,
+ (pd->msg->flags & I2C_M_RD) ? "read" : "write",
+ pd->pos, pd->msg->len);
+
+ /* Kick off TxDMA after preface was done */
+ if (pd->dma_direction == DMA_TO_DEVICE && pd->pos == 0)
+ iic_set_clr(pd, ICIC, ICIC_TDMAE, 0);
+ else if (sr & (ICSR_AL | ICSR_TACK))
+ /* don't interrupt transaction - continue to issue stop */
+ iic_wr(pd, ICSR, sr & ~(ICSR_AL | ICSR_TACK));
+ else if (pd->msg->flags & I2C_M_RD)
+ wakeup = sh_mobile_i2c_isr_rx(pd);
+ else
+ wakeup = sh_mobile_i2c_isr_tx(pd);
+
+ /* Kick off RxDMA after preface was done */
+ if (pd->dma_direction == DMA_FROM_DEVICE && pd->pos == 1)
+ iic_set_clr(pd, ICIC, ICIC_RDMAE, 0);
+
+ if (sr & ICSR_WAIT) /* TODO: add delay here to support slow acks */
+ iic_wr(pd, ICSR, sr & ~ICSR_WAIT);
+
+ if (wakeup) {
+ pd->sr |= SW_DONE;
+ wake_up(&pd->wait);
+ }
+
+ /* defeat write posting to avoid spurious WAIT interrupts */
+ iic_rd(pd, ICSR);
+
+ return IRQ_HANDLED;
+}
+
+static void sh_mobile_i2c_dma_unmap(struct sh_mobile_i2c_data *pd)
+{
+ struct dma_chan *chan = pd->dma_direction == DMA_FROM_DEVICE
+ ? pd->dma_rx : pd->dma_tx;
+
+ dma_unmap_single(chan->device->dev, sg_dma_address(&pd->sg),
+ pd->msg->len, pd->dma_direction);
+
+ pd->dma_direction = DMA_NONE;
+}
+
+static void sh_mobile_i2c_cleanup_dma(struct sh_mobile_i2c_data *pd)
+{
+ if (pd->dma_direction == DMA_NONE)
+ return;
+ else if (pd->dma_direction == DMA_FROM_DEVICE)
+ dmaengine_terminate_all(pd->dma_rx);
+ else if (pd->dma_direction == DMA_TO_DEVICE)
+ dmaengine_terminate_all(pd->dma_tx);
+
+ sh_mobile_i2c_dma_unmap(pd);
+}
+
+static void sh_mobile_i2c_dma_callback(void *data)
+{
+ struct sh_mobile_i2c_data *pd = data;
+
+ sh_mobile_i2c_dma_unmap(pd);
+ pd->pos = pd->msg->len;
+ pd->stop_after_dma = true;
+
+ iic_set_clr(pd, ICIC, 0, ICIC_TDMAE | ICIC_RDMAE);
+}
+
+static struct dma_chan *sh_mobile_i2c_request_dma_chan(struct device *dev,
+ enum dma_transfer_direction dir, dma_addr_t port_addr)
+{
+ struct dma_chan *chan;
+ struct dma_slave_config cfg;
+ char *chan_name = dir == DMA_MEM_TO_DEV ? "tx" : "rx";
+ int ret;
+
+ chan = dma_request_slave_channel_reason(dev, chan_name);
+ if (IS_ERR(chan)) {
+ ret = PTR_ERR(chan);
+ dev_dbg(dev, "request_channel failed for %s (%d)\n", chan_name, ret);
+ return chan;
+ }
+
+ memset(&cfg, 0, sizeof(cfg));
+ cfg.direction = dir;
+ if (dir == DMA_MEM_TO_DEV) {
+ cfg.dst_addr = port_addr;
+ cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ } else {
+ cfg.src_addr = port_addr;
+ cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ }
+
+ ret = dmaengine_slave_config(chan, &cfg);
+ if (ret) {
+ dev_dbg(dev, "slave_config failed for %s (%d)\n", chan_name, ret);
+ dma_release_channel(chan);
+ return ERR_PTR(ret);
+ }
+
+ dev_dbg(dev, "got DMA channel for %s\n", chan_name);
+ return chan;
+}
+
+static void sh_mobile_i2c_xfer_dma(struct sh_mobile_i2c_data *pd)
+{
+ bool read = pd->msg->flags & I2C_M_RD;
+ enum dma_data_direction dir = read ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+ struct dma_chan *chan = read ? pd->dma_rx : pd->dma_tx;
+ struct dma_async_tx_descriptor *txdesc;
+ dma_addr_t dma_addr;
+ dma_cookie_t cookie;
+
+ if (PTR_ERR(chan) == -EPROBE_DEFER) {
+ if (read)
+ chan = pd->dma_rx = sh_mobile_i2c_request_dma_chan(pd->dev, DMA_DEV_TO_MEM,
+ pd->res->start + ICDR);
+ else
+ chan = pd->dma_tx = sh_mobile_i2c_request_dma_chan(pd->dev, DMA_MEM_TO_DEV,
+ pd->res->start + ICDR);
+ }
+
+ if (IS_ERR(chan))
+ return;
+
+ dma_addr = dma_map_single(chan->device->dev, pd->msg->buf, pd->msg->len, dir);
+ if (dma_mapping_error(pd->dev, dma_addr)) {
+ dev_dbg(pd->dev, "dma map failed, using PIO\n");
+ return;
+ }
+
+ sg_dma_len(&pd->sg) = pd->msg->len;
+ sg_dma_address(&pd->sg) = dma_addr;
+
+ pd->dma_direction = dir;
+
+ txdesc = dmaengine_prep_slave_sg(chan, &pd->sg, 1,
+ read ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!txdesc) {
+ dev_dbg(pd->dev, "dma prep slave sg failed, using PIO\n");
+ sh_mobile_i2c_cleanup_dma(pd);
+ return;
+ }
+
+ txdesc->callback = sh_mobile_i2c_dma_callback;
+ txdesc->callback_param = pd;
+
+ cookie = dmaengine_submit(txdesc);
+ if (dma_submit_error(cookie)) {
+ dev_dbg(pd->dev, "submitting dma failed, using PIO\n");
+ sh_mobile_i2c_cleanup_dma(pd);
+ return;
+ }
+
+ dma_async_issue_pending(chan);
+}
+
+static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg,
+ bool do_init)
+{
+ if (usr_msg->len == 0 && (usr_msg->flags & I2C_M_RD)) {
+ dev_err(pd->dev, "Unsupported zero length i2c read\n");
+ return -EOPNOTSUPP;
+ }
+
+ if (do_init) {
+ /* Initialize channel registers */
+ iic_set_clr(pd, ICCR, 0, ICCR_ICE);
+
+ /* Enable channel and configure rx ack */
+ iic_set_clr(pd, ICCR, ICCR_ICE, 0);
+
+ /* Set the clock */
+ iic_wr(pd, ICCL, pd->iccl & 0xff);
+ iic_wr(pd, ICCH, pd->icch & 0xff);
+ }
+
+ pd->msg = usr_msg;
+ pd->pos = -1;
+ pd->sr = 0;
+
+ if (pd->msg->len > 8)
+ sh_mobile_i2c_xfer_dma(pd);
+
+ /* Enable all interrupts to begin with */
+ iic_wr(pd, ICIC, ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
+ return 0;
+}
+
+static int poll_dte(struct sh_mobile_i2c_data *pd)
+{
+ int i;
+
+ for (i = 1000; i; i--) {
+ u_int8_t val = iic_rd(pd, ICSR);
+
+ if (val & ICSR_DTE)
+ break;
+
+ if (val & ICSR_TACK)
+ return -ENXIO;
+
+ udelay(10);
+ }
+
+ return i ? 0 : -ETIMEDOUT;
+}
+
+static int poll_busy(struct sh_mobile_i2c_data *pd)
+{
+ int i;
+
+ for (i = 1000; i; i--) {
+ u_int8_t val = iic_rd(pd, ICSR);
+
+ dev_dbg(pd->dev, "val 0x%02x pd->sr 0x%02x\n", val, pd->sr);
+
+ /* the interrupt handler may wake us up before the
+ * transfer is finished, so poll the hardware
+ * until we're done.
+ */
+ if (!(val & ICSR_BUSY)) {
+ /* handle missing acknowledge and arbitration lost */
+ val |= pd->sr;
+ if (val & ICSR_TACK)
+ return -ENXIO;
+ if (val & ICSR_AL)
+ return -EAGAIN;
+ break;
+ }
+
+ udelay(10);
+ }
+
+ return i ? 0 : -ETIMEDOUT;
+}
+
+static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
+ struct i2c_msg *msgs,
+ int num)
+{
+ struct sh_mobile_i2c_data *pd = i2c_get_adapdata(adapter);
+ struct i2c_msg *msg;
+ int err = 0;
+ int i, k;
+
+ activate_ch(pd);
+
+ /* Process all messages */
+ for (i = 0; i < num; i++) {
+ bool do_start = pd->send_stop || !i;
+ msg = &msgs[i];
+ pd->send_stop = i == num - 1 || msg->flags & I2C_M_STOP;
+ pd->stop_after_dma = false;
+
+ err = start_ch(pd, msg, do_start);
+ if (err)
+ break;
+
+ if (do_start)
+ i2c_op(pd, OP_START, 0);
+
+ /* The interrupt handler takes care of the rest... */
+ k = wait_event_timeout(pd->wait,
+ pd->sr & (ICSR_TACK | SW_DONE),
+ 5 * HZ);
+ if (!k) {
+ dev_err(pd->dev, "Transfer request timed out\n");
+ if (pd->dma_direction != DMA_NONE)
+ sh_mobile_i2c_cleanup_dma(pd);
+
+ err = -ETIMEDOUT;
+ break;
+ }
+
+ if (pd->send_stop)
+ err = poll_busy(pd);
+ else
+ err = poll_dte(pd);
+ if (err < 0)
+ break;
+ }
+
+ deactivate_ch(pd);
+
+ if (!err)
+ err = num;
+ return err;
+}
+
+static u32 sh_mobile_i2c_func(struct i2c_adapter *adapter)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING;
+}
+
+static struct i2c_algorithm sh_mobile_i2c_algorithm = {
+ .functionality = sh_mobile_i2c_func,
+ .master_xfer = sh_mobile_i2c_xfer,
+};
+
+static const struct sh_mobile_dt_config default_dt_config = {
+ .clks_per_count = 1,
+};
+
+static const struct sh_mobile_dt_config fast_clock_dt_config = {
+ .clks_per_count = 2,
+};
+
+static const struct of_device_id sh_mobile_i2c_dt_ids[] = {
+ { .compatible = "renesas,rmobile-iic", .data = &default_dt_config },
+ { .compatible = "renesas,iic-r8a73a4", .data = &fast_clock_dt_config },
+ { .compatible = "renesas,iic-r8a7790", .data = &fast_clock_dt_config },
+ { .compatible = "renesas,iic-r8a7791", .data = &fast_clock_dt_config },
+ { .compatible = "renesas,iic-r8a7792", .data = &fast_clock_dt_config },
+ { .compatible = "renesas,iic-r8a7793", .data = &fast_clock_dt_config },
+ { .compatible = "renesas,iic-r8a7794", .data = &fast_clock_dt_config },
+ { .compatible = "renesas,iic-sh73a0", .data = &fast_clock_dt_config },
+ {},
+};
+MODULE_DEVICE_TABLE(of, sh_mobile_i2c_dt_ids);
+
+static void sh_mobile_i2c_release_dma(struct sh_mobile_i2c_data *pd)
+{
+ if (!IS_ERR(pd->dma_tx)) {
+ dma_release_channel(pd->dma_tx);
+ pd->dma_tx = ERR_PTR(-EPROBE_DEFER);
+ }
+
+ if (!IS_ERR(pd->dma_rx)) {
+ dma_release_channel(pd->dma_rx);
+ pd->dma_rx = ERR_PTR(-EPROBE_DEFER);
+ }
+}
+
+static int sh_mobile_i2c_hook_irqs(struct platform_device *dev, struct sh_mobile_i2c_data *pd)
+{
+ struct resource *res;
+ resource_size_t n;
+ int k = 0, ret;
+
+ while ((res = platform_get_resource(dev, IORESOURCE_IRQ, k))) {
+ for (n = res->start; n <= res->end; n++) {
+ ret = devm_request_irq(&dev->dev, n, sh_mobile_i2c_isr,
+ 0, dev_name(&dev->dev), pd);
+ if (ret) {
+ dev_err(&dev->dev, "cannot request IRQ %pa\n", &n);
+ return ret;
+ }
+ }
+ k++;
+ }
+
+ return k > 0 ? 0 : -ENOENT;
+}
+
+static int sh_mobile_i2c_probe(struct platform_device *dev)
+{
+ struct i2c_sh_mobile_platform_data *pdata = dev_get_platdata(&dev->dev);
+ struct sh_mobile_i2c_data *pd;
+ struct i2c_adapter *adap;
+ struct resource *res;
+ int ret;
+ u32 bus_speed;
+
+ pd = devm_kzalloc(&dev->dev, sizeof(struct sh_mobile_i2c_data), GFP_KERNEL);
+ if (!pd)
+ return -ENOMEM;
+
+ pd->clk = devm_clk_get(&dev->dev, NULL);
+ if (IS_ERR(pd->clk)) {
+ dev_err(&dev->dev, "cannot get clock\n");
+ return PTR_ERR(pd->clk);
+ }
+
+ ret = sh_mobile_i2c_hook_irqs(dev, pd);
+ if (ret)
+ return ret;
+
+ pd->dev = &dev->dev;
+ platform_set_drvdata(dev, pd);
+
+ res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+
+ pd->res = res;
+ pd->reg = devm_ioremap_resource(&dev->dev, res);
+ if (IS_ERR(pd->reg))
+ return PTR_ERR(pd->reg);
+
+ /* Use platform data bus speed or STANDARD_MODE */
+ ret = of_property_read_u32(dev->dev.of_node, "clock-frequency", &bus_speed);
+ pd->bus_speed = ret ? STANDARD_MODE : bus_speed;
+
+ pd->clks_per_count = 1;
+
+ if (dev->dev.of_node) {
+ const struct of_device_id *match;
+
+ match = of_match_device(sh_mobile_i2c_dt_ids, &dev->dev);
+ if (match) {
+ const struct sh_mobile_dt_config *config;
+
+ config = match->data;
+ pd->clks_per_count = config->clks_per_count;
+ }
+ } else {
+ if (pdata && pdata->bus_speed)
+ pd->bus_speed = pdata->bus_speed;
+ if (pdata && pdata->clks_per_count)
+ pd->clks_per_count = pdata->clks_per_count;
+ }
+
+ /* The IIC blocks on SH-Mobile ARM processors
+ * come with two new bits in ICIC.
+ */
+ if (resource_size(res) > 0x17)
+ pd->flags |= IIC_FLAG_HAS_ICIC67;
+
+ ret = sh_mobile_i2c_init(pd);
+ if (ret)
+ return ret;
+
+ /* Init DMA */
+ sg_init_table(&pd->sg, 1);
+ pd->dma_direction = DMA_NONE;
+ pd->dma_rx = pd->dma_tx = ERR_PTR(-EPROBE_DEFER);
+
+ /* Enable Runtime PM for this device.
+ *
+ * Also tell the Runtime PM core to ignore children
+ * for this device since it is valid for us to suspend
+ * this I2C master driver even though the slave devices
+ * on the I2C bus may not be suspended.
+ *
+ * The state of the I2C hardware bus is unaffected by
+ * the Runtime PM state.
+ */
+ pm_suspend_ignore_children(&dev->dev, true);
+ pm_runtime_enable(&dev->dev);
+
+ /* setup the private data */
+ adap = &pd->adap;
+ i2c_set_adapdata(adap, pd);
+
+ adap->owner = THIS_MODULE;
+ adap->algo = &sh_mobile_i2c_algorithm;
+ adap->dev.parent = &dev->dev;
+ adap->retries = 5;
+ adap->nr = dev->id;
+ adap->dev.of_node = dev->dev.of_node;
+
+ strlcpy(adap->name, dev->name, sizeof(adap->name));
+
+ spin_lock_init(&pd->lock);
+ init_waitqueue_head(&pd->wait);
+
+ ret = i2c_add_numbered_adapter(adap);
+ if (ret < 0) {
+ sh_mobile_i2c_release_dma(pd);
+ dev_err(&dev->dev, "cannot add numbered adapter\n");
+ return ret;
+ }
+
+ dev_info(&dev->dev, "I2C adapter %d, bus speed %lu Hz\n", adap->nr, pd->bus_speed);
+
+ return 0;
+}
+
+static int sh_mobile_i2c_remove(struct platform_device *dev)
+{
+ struct sh_mobile_i2c_data *pd = platform_get_drvdata(dev);
+
+ i2c_del_adapter(&pd->adap);
+ sh_mobile_i2c_release_dma(pd);
+ pm_runtime_disable(&dev->dev);
+ return 0;
+}
+
+static int sh_mobile_i2c_runtime_nop(struct device *dev)
+{
+ /* Runtime PM callback shared between ->runtime_suspend()
+ * and ->runtime_resume(). Simply returns success.
+ *
+ * This driver re-initializes all registers after
+ * pm_runtime_get_sync() anyway so there is no need
+ * to save and restore registers here.
+ */
+ return 0;
+}
+
+static const struct dev_pm_ops sh_mobile_i2c_dev_pm_ops = {
+ .runtime_suspend = sh_mobile_i2c_runtime_nop,
+ .runtime_resume = sh_mobile_i2c_runtime_nop,
+};
+
+static struct platform_driver sh_mobile_i2c_driver = {
+ .driver = {
+ .name = "i2c-sh_mobile",
+ .pm = &sh_mobile_i2c_dev_pm_ops,
+ .of_match_table = sh_mobile_i2c_dt_ids,
+ },
+ .probe = sh_mobile_i2c_probe,
+ .remove = sh_mobile_i2c_remove,
+};
+
+static int __init sh_mobile_i2c_adap_init(void)
+{
+ return platform_driver_register(&sh_mobile_i2c_driver);
+}
+subsys_initcall(sh_mobile_i2c_adap_init);
+
+static void __exit sh_mobile_i2c_adap_exit(void)
+{
+ platform_driver_unregister(&sh_mobile_i2c_driver);
+}
+module_exit(sh_mobile_i2c_adap_exit);
+
+MODULE_DESCRIPTION("SuperH Mobile I2C Bus Controller driver");
+MODULE_AUTHOR("Magnus Damm and Wolfram Sang");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:i2c-sh_mobile");
Code Review / kvmfornfv.git / blobdiff