| /* |
| * 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/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; |
| void (*setup)(struct sh_mobile_i2c_data *pd); |
| }; |
| |
| #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 |
| #define ICSTART 0x70 |
| |
| /* 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 |
| |
| #define ICSTART_ICSTART 0x10 |
| |
| 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 = i2c_8bit_addr_from_msg(pd->msg); |
| 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(chan->device->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; |
| long timeout; |
| |
| 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... */ |
| timeout = wait_event_timeout(pd->wait, |
| pd->sr & (ICSR_TACK | SW_DONE), |
| adapter->timeout); |
| if (!timeout) { |
| 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 const struct i2c_algorithm sh_mobile_i2c_algorithm = { |
| .functionality = sh_mobile_i2c_func, |
| .master_xfer = sh_mobile_i2c_xfer, |
| }; |
| |
| /* |
| * r8a7740 chip has lasting errata on I2C I/O pad reset. |
| * this is work-around for it. |
| */ |
| static void sh_mobile_i2c_r8a7740_workaround(struct sh_mobile_i2c_data *pd) |
| { |
| iic_set_clr(pd, ICCR, ICCR_ICE, 0); |
| iic_rd(pd, ICCR); /* dummy read */ |
| |
| iic_set_clr(pd, ICSTART, ICSTART_ICSTART, 0); |
| iic_rd(pd, ICSTART); /* dummy read */ |
| |
| udelay(10); |
| |
| iic_wr(pd, ICCR, ICCR_SCP); |
| iic_wr(pd, ICSTART, 0); |
| |
| udelay(10); |
| |
| iic_wr(pd, ICCR, ICCR_TRS); |
| udelay(10); |
| iic_wr(pd, ICCR, 0); |
| udelay(10); |
| iic_wr(pd, ICCR, ICCR_TRS); |
| udelay(10); |
| } |
| |
| 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 sh_mobile_dt_config r8a7740_dt_config = { |
| .clks_per_count = 1, |
| .setup = sh_mobile_i2c_r8a7740_workaround, |
| }; |
| |
| static const struct of_device_id sh_mobile_i2c_dt_ids[] = { |
| { .compatible = "renesas,iic-r8a73a4", .data = &fast_clock_dt_config }, |
| { .compatible = "renesas,iic-r8a7740", .data = &r8a7740_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,rcar-gen2-iic", .data = &fast_clock_dt_config }, |
| { .compatible = "renesas,iic-r8a7795", .data = &fast_clock_dt_config }, |
| { .compatible = "renesas,rcar-gen3-iic", .data = &fast_clock_dt_config }, |
| { .compatible = "renesas,iic-sh73a0", .data = &fast_clock_dt_config }, |
| { .compatible = "renesas,rmobile-iic", .data = &default_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 sh_mobile_i2c_data *pd; |
| struct i2c_adapter *adap; |
| struct resource *res; |
| const struct of_device_id *match; |
| 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); |
| |
| 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; |
| |
| match = of_match_device(sh_mobile_i2c_dt_ids, &dev->dev); |
| if (match) { |
| const struct sh_mobile_dt_config *config = match->data; |
| |
| pd->clks_per_count = config->clks_per_count; |
| |
| if (config->setup) |
| config->setup(pd); |
| } |
| |
| /* 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); |
| 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"); |