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linux/drivers/i2c/busses/i2c-sh_mobile.c
Uwe Kleine-König e190a0c389 i2c: Convert to platform remove callback returning void 
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Alain Volmat <alain.volmat@foss.st.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Acked-by: Jochen Friedrich <jochen@scram.de>
Acked-by: Peter Rosin <peda@axentia.se>
Acked-by: Vadim Pasternak <vadimp@nvidia.com>
Reviewed-by: Asmaa Mnebhi <asnaa@nvidia.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Chris Pringle <chris.pringle@phabrix.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Tali Perry <tali.perry@nuvoton.com>
Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2023-06-05 09:47:37 +02:00

1022 lines
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// SPDX-License-Identifier: GPL-2.0
/*
* SuperH Mobile I2C Controller
*
* Copyright (C) 2014-19 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>
*/
#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_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;
bool atomic_xfer;
struct resource *res;
struct dma_chan *dma_tx;
struct dma_chan *dma_rx;
struct scatterlist sg;
enum dma_data_direction dma_direction;
u8 *dma_buf;
};
struct sh_mobile_dt_config {
int clks_per_count;
int (*setup)(struct sh_mobile_i2c_data *pd);
};
#define IIC_FLAG_HAS_ICIC67 (1 << 0)
/* 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_check_timing(struct sh_mobile_i2c_data *pd)
{
u16 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 int sh_mobile_i2c_init(struct sh_mobile_i2c_data *pd)
{
unsigned long i2c_clk_khz;
u32 tHIGH, tLOW, tf;
i2c_clk_khz = clk_get_rate(pd->clk) / 1000 / pd->clks_per_count;
if (pd->bus_speed == I2C_MAX_STANDARD_MODE_FREQ) {
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 == I2C_MAX_FAST_MODE_FREQ) {
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);
return sh_mobile_i2c_check_timing(pd);
}
static int sh_mobile_i2c_v2_init(struct sh_mobile_i2c_data *pd)
{
unsigned long clks_per_cycle;
/* L = 5, H = 4, L + H = 9 */
clks_per_cycle = clk_get_rate(pd->clk) / pd->bus_speed;
pd->iccl = DIV_ROUND_UP(clks_per_cycle * 5 / 9 - 1, pd->clks_per_count);
pd->icch = DIV_ROUND_UP(clks_per_cycle * 4 / 9 - 5, pd->clks_per_count);
return sh_mobile_i2c_check_timing(pd);
}
static unsigned char i2c_op(struct sh_mobile_i2c_data *pd, enum sh_mobile_i2c_op op)
{
unsigned char ret = 0;
unsigned long flags;
dev_dbg(pd->dev, "op %d\n", op);
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 client address */
iic_wr(pd, ICIC, ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
iic_wr(pd, ICDR, i2c_8bit_addr_from_msg(pd->msg));
break;
case OP_TX: /* write data */
iic_wr(pd, ICDR, pd->msg->buf[pd->pos]);
break;
case OP_TX_STOP: /* issue a stop (or rep_start) */
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 */
if (!pd->atomic_xfer)
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 */
if (!pd->atomic_xfer)
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 int sh_mobile_i2c_isr_tx(struct sh_mobile_i2c_data *pd)
{
if (pd->pos == pd->msg->len) {
i2c_op(pd, OP_TX_STOP);
return 1;
}
if (pd->pos == -1)
i2c_op(pd, OP_TX_FIRST);
else
i2c_op(pd, OP_TX);
pd->pos++;
return 0;
}
static int sh_mobile_i2c_isr_rx(struct sh_mobile_i2c_data *pd)
{
int real_pos;
/* switch from TX (address) to RX (data) adds two interrupts */
real_pos = pd->pos - 2;
if (pd->pos == -1) {
i2c_op(pd, OP_TX_FIRST);
} else if (pd->pos == 0) {
i2c_op(pd, OP_TX_TO_RX);
} else if (pd->pos == pd->msg->len) {
if (pd->stop_after_dma) {
/* Simulate PIO end condition after DMA transfer */
i2c_op(pd, OP_RX_STOP);
pd->pos++;
goto done;
}
if (real_pos < 0)
i2c_op(pd, OP_RX_STOP);
else
pd->msg->buf[real_pos] = i2c_op(pd, OP_RX_STOP_DATA);
} else if (real_pos >= 0) {
pd->msg->buf[real_pos] = i2c_op(pd, OP_RX);
}
done:
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;
if (!pd->atomic_xfer)
wake_up(&pd->wait);
}
/* defeat write posting to avoid spurious WAIT interrupts */
iic_rd(pd, ICSR);
return IRQ_HANDLED;
}
static void sh_mobile_i2c_cleanup_dma(struct sh_mobile_i2c_data *pd, bool terminate)
{
struct dma_chan *chan = pd->dma_direction == DMA_FROM_DEVICE
? pd->dma_rx : pd->dma_tx;
/* only allowed from thread context! */
if (terminate)
dmaengine_terminate_sync(chan);
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_dma_callback(void *data)
{
struct sh_mobile_i2c_data *pd = data;
sh_mobile_i2c_cleanup_dma(pd, false);
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_chan(dev, chan_name);
if (IS_ERR(chan)) {
dev_dbg(dev, "request_channel failed for %s (%ld)\n", chan_name,
PTR_ERR(chan));
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->dma_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, false);
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, false);
return;
}
dma_async_issue_pending(chan);
}
static void start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg,
bool do_init)
{
if (do_init) {
/* Initialize channel registers */
iic_wr(pd, ICCR, ICCR_SCP);
/* Enable channel and configure rx ack */
iic_wr(pd, ICCR, ICCR_ICE | ICCR_SCP);
/* 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->atomic_xfer)
return;
pd->dma_buf = i2c_get_dma_safe_msg_buf(pd->msg, 8);
if (pd->dma_buf)
sh_mobile_i2c_xfer_dma(pd);
/* Enable all interrupts to begin with */
iic_wr(pd, ICIC, ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
}
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_xfer(struct sh_mobile_i2c_data *pd,
struct i2c_msg *msgs, int num)
{
struct i2c_msg *msg;
int err = 0;
int i;
long time_left;
/* Wake up device and enable clock */
pm_runtime_get_sync(pd->dev);
/* 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;
start_ch(pd, msg, do_start);
if (do_start)
i2c_op(pd, OP_START);
if (pd->atomic_xfer) {
unsigned long j = jiffies + pd->adap.timeout;
time_left = time_before_eq(jiffies, j);
while (time_left &&
!(pd->sr & (ICSR_TACK | SW_DONE))) {
unsigned char sr = iic_rd(pd, ICSR);
if (sr & (ICSR_AL | ICSR_TACK |
ICSR_WAIT | ICSR_DTE)) {
sh_mobile_i2c_isr(0, pd);
udelay(150);
} else {
cpu_relax();
}
time_left = time_before_eq(jiffies, j);
}
} else {
/* The interrupt handler takes care of the rest... */
time_left = wait_event_timeout(pd->wait,
pd->sr & (ICSR_TACK | SW_DONE),
pd->adap.timeout);
/* 'stop_after_dma' tells if DMA xfer was complete */
i2c_put_dma_safe_msg_buf(pd->dma_buf, pd->msg,
pd->stop_after_dma);
}
if (!time_left) {
dev_err(pd->dev, "Transfer request timed out\n");
if (pd->dma_direction != DMA_NONE)
sh_mobile_i2c_cleanup_dma(pd, true);
err = -ETIMEDOUT;
break;
}
if (pd->send_stop)
err = poll_busy(pd);
else
err = poll_dte(pd);
if (err < 0)
break;
}
/* Disable channel */
iic_wr(pd, ICCR, ICCR_SCP);
/* Disable clock and mark device as idle */
pm_runtime_put_sync(pd->dev);
return err ?: num;
}
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);
pd->atomic_xfer = false;
return sh_mobile_xfer(pd, msgs, num);
}
static int sh_mobile_i2c_xfer_atomic(struct i2c_adapter *adapter,
struct i2c_msg *msgs,
int num)
{
struct sh_mobile_i2c_data *pd = i2c_get_adapdata(adapter);
pd->atomic_xfer = true;
return sh_mobile_xfer(pd, msgs, num);
}
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,
.master_xfer_atomic = sh_mobile_i2c_xfer_atomic,
};
static const struct i2c_adapter_quirks sh_mobile_i2c_quirks = {
.flags = I2C_AQ_NO_ZERO_LEN_READ,
};
/*
* r8a7740 has an errata regarding I2C I/O pad reset needing this workaround.
*/
static int 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);
return sh_mobile_i2c_init(pd);
}
static const struct sh_mobile_dt_config default_dt_config = {
.clks_per_count = 1,
.setup = sh_mobile_i2c_init,
};
static const struct sh_mobile_dt_config fast_clock_dt_config = {
.clks_per_count = 2,
.setup = sh_mobile_i2c_init,
};
static const struct sh_mobile_dt_config v2_freq_calc_dt_config = {
.clks_per_count = 2,
.setup = sh_mobile_i2c_v2_init,
};
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-r8a774c0", .data = &v2_freq_calc_dt_config },
{ .compatible = "renesas,iic-r8a7790", .data = &v2_freq_calc_dt_config },
{ .compatible = "renesas,iic-r8a7791", .data = &v2_freq_calc_dt_config },
{ .compatible = "renesas,iic-r8a7792", .data = &v2_freq_calc_dt_config },
{ .compatible = "renesas,iic-r8a7793", .data = &v2_freq_calc_dt_config },
{ .compatible = "renesas,iic-r8a7794", .data = &v2_freq_calc_dt_config },
{ .compatible = "renesas,iic-r8a7795", .data = &v2_freq_calc_dt_config },
{ .compatible = "renesas,iic-r8a77990", .data = &v2_freq_calc_dt_config },
{ .compatible = "renesas,iic-sh73a0", .data = &fast_clock_dt_config },
{ .compatible = "renesas,rcar-gen2-iic", .data = &v2_freq_calc_dt_config },
{ .compatible = "renesas,rcar-gen3-iic", .data = &v2_freq_calc_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 device_node *np = dev_of_node(&dev->dev);
int k = 0, ret;
if (np) {
int irq;
while ((irq = platform_get_irq_optional(dev, k)) != -ENXIO) {
if (irq < 0)
return irq;
ret = devm_request_irq(&dev->dev, irq, sh_mobile_i2c_isr,
0, dev_name(&dev->dev), pd);
if (ret) {
dev_err(&dev->dev, "cannot request IRQ %d\n", irq);
return ret;
}
k++;
}
} else {
struct resource *res;
resource_size_t n;
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 sh_mobile_dt_config *config;
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 || !bus_speed) ? I2C_MAX_STANDARD_MODE_FREQ : bus_speed;
pd->clks_per_count = 1;
/* Newer variants come with two new bits in ICIC */
if (resource_size(res) > 0x17)
pd->flags |= IIC_FLAG_HAS_ICIC67;
pm_runtime_enable(&dev->dev);
pm_runtime_get_sync(&dev->dev);
config = of_device_get_match_data(&dev->dev);
if (config) {
pd->clks_per_count = config->clks_per_count;
ret = config->setup(pd);
} else {
ret = sh_mobile_i2c_init(pd);
}
pm_runtime_put_sync(&dev->dev);
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);
/* setup the private data */
adap = &pd->adap;
i2c_set_adapdata(adap, pd);
adap->owner = THIS_MODULE;
adap->algo = &sh_mobile_i2c_algorithm;
adap->quirks = &sh_mobile_i2c_quirks;
adap->dev.parent = &dev->dev;
adap->retries = 5;
adap->nr = dev->id;
adap->dev.of_node = dev->dev.of_node;
strscpy(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 void 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);
}
#ifdef CONFIG_PM_SLEEP
static int sh_mobile_i2c_suspend(struct device *dev)
{
struct sh_mobile_i2c_data *pd = dev_get_drvdata(dev);
i2c_mark_adapter_suspended(&pd->adap);
return 0;
}
static int sh_mobile_i2c_resume(struct device *dev)
{
struct sh_mobile_i2c_data *pd = dev_get_drvdata(dev);
i2c_mark_adapter_resumed(&pd->adap);
return 0;
}
static const struct dev_pm_ops sh_mobile_i2c_pm_ops = {
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(sh_mobile_i2c_suspend,
sh_mobile_i2c_resume)
};
#define DEV_PM_OPS (&sh_mobile_i2c_pm_ops)
#else
#define DEV_PM_OPS NULL
#endif /* CONFIG_PM_SLEEP */
static struct platform_driver sh_mobile_i2c_driver = {
.driver = {
.name = "i2c-sh_mobile",
.of_match_table = sh_mobile_i2c_dt_ids,
.pm = DEV_PM_OPS,
},
.probe = sh_mobile_i2c_probe,
.remove_new = 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");
MODULE_AUTHOR("Wolfram Sang");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:i2c-sh_mobile");
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