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linux-next/drivers/i2c/busses/i2c-jz4780.c
Wolfram Sang caf280800a i2c: jz4780: really prevent potential division by zero 
Make sure we avoid a division-by-zero OOPS in case clock-frequency is
set too low in DT. Add missing '\n' while we are here.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Axel Lin <axel.lin@ingics.com>
2016-04-09 08:36:44 +02:00

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/*
* Ingenic JZ4780 I2C bus driver
*
* Copyright (C) 2006 - 2009 Ingenic Semiconductor Inc.
* Copyright (C) 2015 Imagination Technologies
*
* 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.
*/
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/errno.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/platform_device.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/time.h>
#define JZ4780_I2C_CTRL 0x00
#define JZ4780_I2C_TAR 0x04
#define JZ4780_I2C_SAR 0x08
#define JZ4780_I2C_DC 0x10
#define JZ4780_I2C_SHCNT 0x14
#define JZ4780_I2C_SLCNT 0x18
#define JZ4780_I2C_FHCNT 0x1C
#define JZ4780_I2C_FLCNT 0x20
#define JZ4780_I2C_INTST 0x2C
#define JZ4780_I2C_INTM 0x30
#define JZ4780_I2C_RXTL 0x38
#define JZ4780_I2C_TXTL 0x3C
#define JZ4780_I2C_CINTR 0x40
#define JZ4780_I2C_CRXUF 0x44
#define JZ4780_I2C_CRXOF 0x48
#define JZ4780_I2C_CTXOF 0x4C
#define JZ4780_I2C_CRXREQ 0x50
#define JZ4780_I2C_CTXABRT 0x54
#define JZ4780_I2C_CRXDONE 0x58
#define JZ4780_I2C_CACT 0x5C
#define JZ4780_I2C_CSTP 0x60
#define JZ4780_I2C_CSTT 0x64
#define JZ4780_I2C_CGC 0x68
#define JZ4780_I2C_ENB 0x6C
#define JZ4780_I2C_STA 0x70
#define JZ4780_I2C_TXABRT 0x80
#define JZ4780_I2C_DMACR 0x88
#define JZ4780_I2C_DMATDLR 0x8C
#define JZ4780_I2C_DMARDLR 0x90
#define JZ4780_I2C_SDASU 0x94
#define JZ4780_I2C_ACKGC 0x98
#define JZ4780_I2C_ENSTA 0x9C
#define JZ4780_I2C_SDAHD 0xD0
#define JZ4780_I2C_CTRL_STPHLD BIT(7)
#define JZ4780_I2C_CTRL_SLVDIS BIT(6)
#define JZ4780_I2C_CTRL_REST BIT(5)
#define JZ4780_I2C_CTRL_MATP BIT(4)
#define JZ4780_I2C_CTRL_SATP BIT(3)
#define JZ4780_I2C_CTRL_SPDF BIT(2)
#define JZ4780_I2C_CTRL_SPDS BIT(1)
#define JZ4780_I2C_CTRL_MD BIT(0)
#define JZ4780_I2C_STA_SLVACT BIT(6)
#define JZ4780_I2C_STA_MSTACT BIT(5)
#define JZ4780_I2C_STA_RFF BIT(4)
#define JZ4780_I2C_STA_RFNE BIT(3)
#define JZ4780_I2C_STA_TFE BIT(2)
#define JZ4780_I2C_STA_TFNF BIT(1)
#define JZ4780_I2C_STA_ACT BIT(0)
static const char * const jz4780_i2c_abrt_src[] = {
"ABRT_7B_ADDR_NOACK",
"ABRT_10ADDR1_NOACK",
"ABRT_10ADDR2_NOACK",
"ABRT_XDATA_NOACK",
"ABRT_GCALL_NOACK",
"ABRT_GCALL_READ",
"ABRT_HS_ACKD",
"SBYTE_ACKDET",
"ABRT_HS_NORSTRT",
"SBYTE_NORSTRT",
"ABRT_10B_RD_NORSTRT",
"ABRT_MASTER_DIS",
"ARB_LOST",
"SLVFLUSH_TXFIFO",
"SLV_ARBLOST",
"SLVRD_INTX",
};
#define JZ4780_I2C_INTST_IGC BIT(11)
#define JZ4780_I2C_INTST_ISTT BIT(10)
#define JZ4780_I2C_INTST_ISTP BIT(9)
#define JZ4780_I2C_INTST_IACT BIT(8)
#define JZ4780_I2C_INTST_RXDN BIT(7)
#define JZ4780_I2C_INTST_TXABT BIT(6)
#define JZ4780_I2C_INTST_RDREQ BIT(5)
#define JZ4780_I2C_INTST_TXEMP BIT(4)
#define JZ4780_I2C_INTST_TXOF BIT(3)
#define JZ4780_I2C_INTST_RXFL BIT(2)
#define JZ4780_I2C_INTST_RXOF BIT(1)
#define JZ4780_I2C_INTST_RXUF BIT(0)
#define JZ4780_I2C_INTM_MIGC BIT(11)
#define JZ4780_I2C_INTM_MISTT BIT(10)
#define JZ4780_I2C_INTM_MISTP BIT(9)
#define JZ4780_I2C_INTM_MIACT BIT(8)
#define JZ4780_I2C_INTM_MRXDN BIT(7)
#define JZ4780_I2C_INTM_MTXABT BIT(6)
#define JZ4780_I2C_INTM_MRDREQ BIT(5)
#define JZ4780_I2C_INTM_MTXEMP BIT(4)
#define JZ4780_I2C_INTM_MTXOF BIT(3)
#define JZ4780_I2C_INTM_MRXFL BIT(2)
#define JZ4780_I2C_INTM_MRXOF BIT(1)
#define JZ4780_I2C_INTM_MRXUF BIT(0)
#define JZ4780_I2C_DC_READ BIT(8)
#define JZ4780_I2C_SDAHD_HDENB BIT(8)
#define JZ4780_I2C_ENB_I2C BIT(0)
#define JZ4780_I2CSHCNT_ADJUST(n) (((n) - 8) < 6 ? 6 : ((n) - 8))
#define JZ4780_I2CSLCNT_ADJUST(n) (((n) - 1) < 8 ? 8 : ((n) - 1))
#define JZ4780_I2CFHCNT_ADJUST(n) (((n) - 8) < 6 ? 6 : ((n) - 8))
#define JZ4780_I2CFLCNT_ADJUST(n) (((n) - 1) < 8 ? 8 : ((n) - 1))
#define JZ4780_I2C_FIFO_LEN 16
#define TX_LEVEL 3
#define RX_LEVEL (JZ4780_I2C_FIFO_LEN - TX_LEVEL - 1)
#define JZ4780_I2C_TIMEOUT 300
#define BUFSIZE 200
struct jz4780_i2c {
void __iomem *iomem;
int irq;
struct clk *clk;
struct i2c_adapter adap;
/* lock to protect rbuf and wbuf between xfer_rd/wr and irq handler */
spinlock_t lock;
/* beginning of lock scope */
unsigned char *rbuf;
int rd_total_len;
int rd_data_xfered;
int rd_cmd_xfered;
unsigned char *wbuf;
int wt_len;
int is_write;
int stop_hold;
int speed;
int data_buf[BUFSIZE];
int cmd_buf[BUFSIZE];
int cmd;
/* end of lock scope */
struct completion trans_waitq;
};
static inline unsigned short jz4780_i2c_readw(struct jz4780_i2c *i2c,
unsigned long offset)
{
return readw(i2c->iomem + offset);
}
static inline void jz4780_i2c_writew(struct jz4780_i2c *i2c,
unsigned long offset, unsigned short val)
{
writew(val, i2c->iomem + offset);
}
static int jz4780_i2c_disable(struct jz4780_i2c *i2c)
{
unsigned short regval;
unsigned long loops = 5;
jz4780_i2c_writew(i2c, JZ4780_I2C_ENB, 0);
do {
regval = jz4780_i2c_readw(i2c, JZ4780_I2C_ENSTA);
if (!(regval & JZ4780_I2C_ENB_I2C))
return 0;
usleep_range(5000, 15000);
} while (--loops);
dev_err(&i2c->adap.dev, "disable failed: ENSTA=0x%04x\n", regval);
return -ETIMEDOUT;
}
static int jz4780_i2c_enable(struct jz4780_i2c *i2c)
{
unsigned short regval;
unsigned long loops = 5;
jz4780_i2c_writew(i2c, JZ4780_I2C_ENB, 1);
do {
regval = jz4780_i2c_readw(i2c, JZ4780_I2C_ENSTA);
if (regval & JZ4780_I2C_ENB_I2C)
return 0;
usleep_range(5000, 15000);
} while (--loops);
dev_err(&i2c->adap.dev, "enable failed: ENSTA=0x%04x\n", regval);
return -ETIMEDOUT;
}
static int jz4780_i2c_set_target(struct jz4780_i2c *i2c, unsigned char address)
{
unsigned short regval;
unsigned long loops = 5;
do {
regval = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
if ((regval & JZ4780_I2C_STA_TFE) &&
!(regval & JZ4780_I2C_STA_MSTACT))
break;
usleep_range(5000, 15000);
} while (--loops);
if (loops) {
jz4780_i2c_writew(i2c, JZ4780_I2C_TAR, address);
return 0;
}
dev_err(&i2c->adap.dev,
"set device to address 0x%02x failed, STA=0x%04x\n",
address, regval);
return -ENXIO;
}
static int jz4780_i2c_set_speed(struct jz4780_i2c *i2c)
{
int dev_clk_khz = clk_get_rate(i2c->clk) / 1000;
int cnt_high = 0; /* HIGH period count of the SCL clock */
int cnt_low = 0; /* LOW period count of the SCL clock */
int cnt_period = 0; /* period count of the SCL clock */
int setup_time = 0;
int hold_time = 0;
unsigned short tmp = 0;
int i2c_clk = i2c->speed;
if (jz4780_i2c_disable(i2c))
dev_dbg(&i2c->adap.dev, "i2c not disabled\n");
/*
* 1 JZ4780_I2C cycle equals to cnt_period PCLK(i2c_clk)
* standard mode, min LOW and HIGH period are 4700 ns and 4000 ns
* fast mode, min LOW and HIGH period are 1300 ns and 600 ns
*/
cnt_period = dev_clk_khz / i2c_clk;
if (i2c_clk <= 100)
cnt_high = (cnt_period * 4000) / (4700 + 4000);
else
cnt_high = (cnt_period * 600) / (1300 + 600);
cnt_low = cnt_period - cnt_high;
/*
* NOTE: JZ4780_I2C_CTRL_REST can't set when i2c enabled, because
* normal read are 2 messages, we cannot disable i2c controller
* between these two messages, this means that we must always set
* JZ4780_I2C_CTRL_REST when init JZ4780_I2C_CTRL
*
*/
if (i2c_clk <= 100) {
tmp = JZ4780_I2C_CTRL_SPDS | JZ4780_I2C_CTRL_REST
| JZ4780_I2C_CTRL_SLVDIS | JZ4780_I2C_CTRL_MD;
jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
jz4780_i2c_writew(i2c, JZ4780_I2C_SHCNT,
JZ4780_I2CSHCNT_ADJUST(cnt_high));
jz4780_i2c_writew(i2c, JZ4780_I2C_SLCNT,
JZ4780_I2CSLCNT_ADJUST(cnt_low));
} else {
tmp = JZ4780_I2C_CTRL_SPDF | JZ4780_I2C_CTRL_REST
| JZ4780_I2C_CTRL_SLVDIS | JZ4780_I2C_CTRL_MD;
jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
jz4780_i2c_writew(i2c, JZ4780_I2C_FHCNT,
JZ4780_I2CFHCNT_ADJUST(cnt_high));
jz4780_i2c_writew(i2c, JZ4780_I2C_FLCNT,
JZ4780_I2CFLCNT_ADJUST(cnt_low));
}
/*
* a i2c device must internally provide a hold time at least 300ns
* tHD:DAT
* Standard Mode: min=300ns, max=3450ns
* Fast Mode: min=0ns, max=900ns
* tSU:DAT
* Standard Mode: min=250ns, max=infinite
* Fast Mode: min=100(250ns is recommended), max=infinite
*
* 1i2c_clk = 10^6 / dev_clk_khz
* on FPGA, dev_clk_khz = 12000, so 1i2c_clk = 1000/12 = 83ns
* on Pisces(1008M), dev_clk_khz=126000, so 1i2c_clk = 1000 / 126 = 8ns
*
* The actual hold time is (SDAHD + 1) * (i2c_clk period).
*
* Length of setup time calculated using (SDASU - 1) * (ic_clk_period)
*
*/
if (i2c_clk <= 100) { /* standard mode */
setup_time = 300;
hold_time = 400;
} else {
setup_time = 450;
hold_time = 450;
}
hold_time = ((hold_time * dev_clk_khz) / 1000000) - 1;
setup_time = ((setup_time * dev_clk_khz) / 1000000) + 1;
if (setup_time > 255)
setup_time = 255;
if (setup_time <= 0)
setup_time = 1;
jz4780_i2c_writew(i2c, JZ4780_I2C_SDASU, setup_time);
if (hold_time > 255)
hold_time = 255;
if (hold_time >= 0) {
/*i2c hold time enable */
hold_time |= JZ4780_I2C_SDAHD_HDENB;
jz4780_i2c_writew(i2c, JZ4780_I2C_SDAHD, hold_time);
} else {
/* disable hold time */
jz4780_i2c_writew(i2c, JZ4780_I2C_SDAHD, 0);
}
return 0;
}
static int jz4780_i2c_cleanup(struct jz4780_i2c *i2c)
{
int ret;
unsigned long flags;
unsigned short tmp;
spin_lock_irqsave(&i2c->lock, flags);
/* can send stop now if need */
tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
tmp &= ~JZ4780_I2C_CTRL_STPHLD;
jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
/* disable all interrupts first */
jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0);
/* then clear all interrupts */
jz4780_i2c_readw(i2c, JZ4780_I2C_CTXABRT);
jz4780_i2c_readw(i2c, JZ4780_I2C_CINTR);
/* then disable the controller */
tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
tmp &= ~JZ4780_I2C_ENB_I2C;
jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
udelay(10);
tmp |= JZ4780_I2C_ENB_I2C;
jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
spin_unlock_irqrestore(&i2c->lock, flags);
ret = jz4780_i2c_disable(i2c);
if (ret)
dev_err(&i2c->adap.dev,
"unable to disable device during cleanup!\n");
if (unlikely(jz4780_i2c_readw(i2c, JZ4780_I2C_INTM)
& jz4780_i2c_readw(i2c, JZ4780_I2C_INTST)))
dev_err(&i2c->adap.dev,
"device has interrupts after a complete cleanup!\n");
return ret;
}
static int jz4780_i2c_prepare(struct jz4780_i2c *i2c)
{
jz4780_i2c_set_speed(i2c);
return jz4780_i2c_enable(i2c);
}
static void jz4780_i2c_send_rcmd(struct jz4780_i2c *i2c, int cmd_count)
{
int i;
for (i = 0; i < cmd_count; i++)
jz4780_i2c_writew(i2c, JZ4780_I2C_DC, JZ4780_I2C_DC_READ);
}
static void jz4780_i2c_trans_done(struct jz4780_i2c *i2c)
{
jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0);
complete(&i2c->trans_waitq);
}
static irqreturn_t jz4780_i2c_irq(int irqno, void *dev_id)
{
unsigned short tmp;
unsigned short intst;
unsigned short intmsk;
struct jz4780_i2c *i2c = dev_id;
unsigned long flags;
spin_lock_irqsave(&i2c->lock, flags);
intmsk = jz4780_i2c_readw(i2c, JZ4780_I2C_INTM);
intst = jz4780_i2c_readw(i2c, JZ4780_I2C_INTST);
intst &= intmsk;
if (intst & JZ4780_I2C_INTST_TXABT) {
jz4780_i2c_trans_done(i2c);
goto done;
}
if (intst & JZ4780_I2C_INTST_RXOF) {
dev_dbg(&i2c->adap.dev, "received fifo overflow!\n");
jz4780_i2c_trans_done(i2c);
goto done;
}
/*
* When reading, always drain RX FIFO before we send more Read
* Commands to avoid fifo overrun
*/
if (i2c->is_write == 0) {
int rd_left;
while ((jz4780_i2c_readw(i2c, JZ4780_I2C_STA)
& JZ4780_I2C_STA_RFNE)) {
*(i2c->rbuf++) = jz4780_i2c_readw(i2c, JZ4780_I2C_DC)
& 0xff;
i2c->rd_data_xfered++;
if (i2c->rd_data_xfered == i2c->rd_total_len) {
jz4780_i2c_trans_done(i2c);
goto done;
}
}
rd_left = i2c->rd_total_len - i2c->rd_data_xfered;
if (rd_left <= JZ4780_I2C_FIFO_LEN)
jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, rd_left - 1);
}
if (intst & JZ4780_I2C_INTST_TXEMP) {
if (i2c->is_write == 0) {
int cmd_left = i2c->rd_total_len - i2c->rd_cmd_xfered;
int max_send = (JZ4780_I2C_FIFO_LEN - 1)
- (i2c->rd_cmd_xfered
- i2c->rd_data_xfered);
int cmd_to_send = min(cmd_left, max_send);
if (i2c->rd_cmd_xfered != 0)
cmd_to_send = min(cmd_to_send,
JZ4780_I2C_FIFO_LEN
- TX_LEVEL - 1);
if (cmd_to_send) {
jz4780_i2c_send_rcmd(i2c, cmd_to_send);
i2c->rd_cmd_xfered += cmd_to_send;
}
cmd_left = i2c->rd_total_len - i2c->rd_cmd_xfered;
if (cmd_left == 0) {
intmsk = jz4780_i2c_readw(i2c, JZ4780_I2C_INTM);
intmsk &= ~JZ4780_I2C_INTM_MTXEMP;
jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, intmsk);
tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
tmp &= ~JZ4780_I2C_CTRL_STPHLD;
jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
}
} else {
unsigned short data;
unsigned short i2c_sta;
i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
while ((i2c_sta & JZ4780_I2C_STA_TFNF) &&
(i2c->wt_len > 0)) {
i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
data = *i2c->wbuf;
data &= ~JZ4780_I2C_DC_READ;
jz4780_i2c_writew(i2c, JZ4780_I2C_DC,
data);
i2c->wbuf++;
i2c->wt_len--;
}
if (i2c->wt_len == 0) {
if (!i2c->stop_hold) {
tmp = jz4780_i2c_readw(i2c,
JZ4780_I2C_CTRL);
tmp &= ~JZ4780_I2C_CTRL_STPHLD;
jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL,
tmp);
}
jz4780_i2c_trans_done(i2c);
goto done;
}
}
}
done:
spin_unlock_irqrestore(&i2c->lock, flags);
return IRQ_HANDLED;
}
static void jz4780_i2c_txabrt(struct jz4780_i2c *i2c, int src)
{
int i;
dev_err(&i2c->adap.dev, "txabrt: 0x%08x\n", src);
dev_err(&i2c->adap.dev, "device addr=%x\n",
jz4780_i2c_readw(i2c, JZ4780_I2C_TAR));
dev_err(&i2c->adap.dev, "send cmd count:%d %d\n",
i2c->cmd, i2c->cmd_buf[i2c->cmd]);
dev_err(&i2c->adap.dev, "receive data count:%d %d\n",
i2c->cmd, i2c->data_buf[i2c->cmd]);
for (i = 0; i < 16; i++) {
if (src & BIT(i))
dev_dbg(&i2c->adap.dev, "I2C TXABRT[%d]=%s\n",
i, jz4780_i2c_abrt_src[i]);
}
}
static inline int jz4780_i2c_xfer_read(struct jz4780_i2c *i2c,
unsigned char *buf, int len, int cnt,
int idx)
{
int ret = 0;
long timeout;
int wait_time = JZ4780_I2C_TIMEOUT * (len + 5);
unsigned short tmp;
unsigned long flags;
memset(buf, 0, len);
spin_lock_irqsave(&i2c->lock, flags);
i2c->stop_hold = 0;
i2c->is_write = 0;
i2c->rbuf = buf;
i2c->rd_total_len = len;
i2c->rd_data_xfered = 0;
i2c->rd_cmd_xfered = 0;
if (len <= JZ4780_I2C_FIFO_LEN)
jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, len - 1);
else
jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, RX_LEVEL);
jz4780_i2c_writew(i2c, JZ4780_I2C_TXTL, TX_LEVEL);
jz4780_i2c_writew(i2c, JZ4780_I2C_INTM,
JZ4780_I2C_INTM_MRXFL | JZ4780_I2C_INTM_MTXEMP
| JZ4780_I2C_INTM_MTXABT | JZ4780_I2C_INTM_MRXOF);
tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
tmp |= JZ4780_I2C_CTRL_STPHLD;
jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
spin_unlock_irqrestore(&i2c->lock, flags);
timeout = wait_for_completion_timeout(&i2c->trans_waitq,
msecs_to_jiffies(wait_time));
if (!timeout) {
dev_err(&i2c->adap.dev, "irq read timeout\n");
dev_dbg(&i2c->adap.dev, "send cmd count:%d %d\n",
i2c->cmd, i2c->cmd_buf[i2c->cmd]);
dev_dbg(&i2c->adap.dev, "receive data count:%d %d\n",
i2c->cmd, i2c->data_buf[i2c->cmd]);
ret = -EIO;
}
tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_TXABRT);
if (tmp) {
jz4780_i2c_txabrt(i2c, tmp);
ret = -EIO;
}
return ret;
}
static inline int jz4780_i2c_xfer_write(struct jz4780_i2c *i2c,
unsigned char *buf, int len,
int cnt, int idx)
{
int ret = 0;
int wait_time = JZ4780_I2C_TIMEOUT * (len + 5);
long timeout;
unsigned short tmp;
unsigned long flags;
spin_lock_irqsave(&i2c->lock, flags);
if (idx < (cnt - 1))
i2c->stop_hold = 1;
else
i2c->stop_hold = 0;
i2c->is_write = 1;
i2c->wbuf = buf;
i2c->wt_len = len;
jz4780_i2c_writew(i2c, JZ4780_I2C_TXTL, TX_LEVEL);
jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, JZ4780_I2C_INTM_MTXEMP
| JZ4780_I2C_INTM_MTXABT);
tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
tmp |= JZ4780_I2C_CTRL_STPHLD;
jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
spin_unlock_irqrestore(&i2c->lock, flags);
timeout = wait_for_completion_timeout(&i2c->trans_waitq,
msecs_to_jiffies(wait_time));
if (timeout && !i2c->stop_hold) {
unsigned short i2c_sta;
int write_in_process;
timeout = JZ4780_I2C_TIMEOUT * 100;
for (; timeout > 0; timeout--) {
i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
write_in_process = (i2c_sta & JZ4780_I2C_STA_MSTACT) ||
!(i2c_sta & JZ4780_I2C_STA_TFE);
if (!write_in_process)
break;
udelay(10);
}
}
if (!timeout) {
dev_err(&i2c->adap.dev, "write wait timeout\n");
ret = -EIO;
}
tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_TXABRT);
if (tmp) {
jz4780_i2c_txabrt(i2c, tmp);
ret = -EIO;
}
return ret;
}
static int jz4780_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msg,
int count)
{
int i = -EIO;
int ret = 0;
struct jz4780_i2c *i2c = adap->algo_data;
ret = jz4780_i2c_prepare(i2c);
if (ret) {
dev_err(&i2c->adap.dev, "I2C prepare failed\n");
goto out;
}
if (msg->addr != jz4780_i2c_readw(i2c, JZ4780_I2C_TAR)) {
ret = jz4780_i2c_set_target(i2c, msg->addr);
if (ret)
goto out;
}
for (i = 0; i < count; i++, msg++) {
if (msg->flags & I2C_M_RD)
ret = jz4780_i2c_xfer_read(i2c, msg->buf, msg->len,
count, i);
else
ret = jz4780_i2c_xfer_write(i2c, msg->buf, msg->len,
count, i);
if (ret)
goto out;
}
ret = i;
out:
jz4780_i2c_cleanup(i2c);
return ret;
}
static u32 jz4780_i2c_functionality(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}
static const struct i2c_algorithm jz4780_i2c_algorithm = {
.master_xfer = jz4780_i2c_xfer,
.functionality = jz4780_i2c_functionality,
};
static const struct of_device_id jz4780_i2c_of_matches[] = {
{ .compatible = "ingenic,jz4780-i2c", },
{ /* sentinel */ }
};
static int jz4780_i2c_probe(struct platform_device *pdev)
{
int ret = 0;
unsigned int clk_freq = 0;
unsigned short tmp;
struct resource *r;
struct jz4780_i2c *i2c;
i2c = devm_kzalloc(&pdev->dev, sizeof(struct jz4780_i2c), GFP_KERNEL);
if (!i2c)
return -ENOMEM;
i2c->adap.owner = THIS_MODULE;
i2c->adap.algo = &jz4780_i2c_algorithm;
i2c->adap.algo_data = i2c;
i2c->adap.retries = 5;
i2c->adap.dev.parent = &pdev->dev;
i2c->adap.dev.of_node = pdev->dev.of_node;
sprintf(i2c->adap.name, "%s", pdev->name);
init_completion(&i2c->trans_waitq);
spin_lock_init(&i2c->lock);
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
i2c->iomem = devm_ioremap_resource(&pdev->dev, r);
if (IS_ERR(i2c->iomem))
return PTR_ERR(i2c->iomem);
platform_set_drvdata(pdev, i2c);
i2c->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(i2c->clk))
return PTR_ERR(i2c->clk);
ret = clk_prepare_enable(i2c->clk);
if (ret)
return ret;
ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
&clk_freq);
if (ret) {
dev_err(&pdev->dev, "clock-frequency not specified in DT\n");
goto err;
}
i2c->speed = clk_freq / 1000;
if (i2c->speed == 0) {
ret = -EINVAL;
dev_err(&pdev->dev, "clock-frequency minimum is 1000\n");
goto err;
}
jz4780_i2c_set_speed(i2c);
dev_info(&pdev->dev, "Bus frequency is %d KHz\n", i2c->speed);
tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
tmp &= ~JZ4780_I2C_CTRL_STPHLD;
jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0x0);
i2c->cmd = 0;
memset(i2c->cmd_buf, 0, BUFSIZE);
memset(i2c->data_buf, 0, BUFSIZE);
i2c->irq = platform_get_irq(pdev, 0);
ret = devm_request_irq(&pdev->dev, i2c->irq, jz4780_i2c_irq, 0,
dev_name(&pdev->dev), i2c);
if (ret)
goto err;
ret = i2c_add_adapter(&i2c->adap);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to add bus\n");
goto err;
}
return 0;
err:
clk_disable_unprepare(i2c->clk);
return ret;
}
static int jz4780_i2c_remove(struct platform_device *pdev)
{
struct jz4780_i2c *i2c = platform_get_drvdata(pdev);
clk_disable_unprepare(i2c->clk);
i2c_del_adapter(&i2c->adap);
return 0;
}
static struct platform_driver jz4780_i2c_driver = {
.probe = jz4780_i2c_probe,
.remove = jz4780_i2c_remove,
.driver = {
.name = "jz4780-i2c",
.of_match_table = of_match_ptr(jz4780_i2c_of_matches),
},
};
module_platform_driver(jz4780_i2c_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("ztyan<ztyan@ingenic.cn>");
MODULE_DESCRIPTION("i2c driver for JZ4780 SoCs");
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