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lpi2c: Add bus busy error handling

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When doing "i2c dev 4; i2c probe" with ENET daughter card connected
on iMX8QXP MEK board, we met a i2c bus busy issue, that the BBF of
lpi2c always show busy, but the master is idle, and stop is detected
(SDF set).

This patch addes a handling to re-init the lpi2c master for this
case. Then the issue can be worked around.

Signed-off-by: Ye Li <ye.li@nxp.com>
Acked-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
This commit is contained in:
Ye Li 2018-07-08 11:46:43 +08:00 • committed by Heiko Schocher
parent d144f61ad3
commit 971490c892
1 changed files with 32 additions and 21 deletions
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51
drivers/i2c/imx_lpi2c.c
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@ -18,6 +18,8 @@
#define LPI2C_NACK_TOUT_MS 1 #define LPI2C_NACK_TOUT_MS 1
#define LPI2C_TIMEOUT_MS 100 #define LPI2C_TIMEOUT_MS 100
static int bus_i2c_init(struct udevice *bus, int speed);
/* Weak linked function for overridden by some SoC power function */ /* Weak linked function for overridden by some SoC power function */
int __weak init_i2c_power(unsigned i2c_num) int __weak init_i2c_power(unsigned i2c_num)
{ {
@ -91,8 +93,9 @@ static int bus_i2c_wait_for_tx_ready(struct imx_lpi2c_reg *regs)
return result; return result;
} }
static int bus_i2c_send(struct imx_lpi2c_reg *regs, u8 *txbuf, int len) static int bus_i2c_send(struct udevice *bus, u8 *txbuf, int len)
{ {
struct imx_lpi2c_reg *regs = (struct imx_lpi2c_reg *)devfdt_get_addr(bus);
lpi2c_status_t result = LPI2C_SUCESS; lpi2c_status_t result = LPI2C_SUCESS;
/* empty tx */ /* empty tx */
@ -111,8 +114,9 @@ static int bus_i2c_send(struct imx_lpi2c_reg *regs, u8 *txbuf, int len)
return result; return result;
} }
static int bus_i2c_receive(struct imx_lpi2c_reg *regs, u8 *rxbuf, int len) static int bus_i2c_receive(struct udevice *bus, u8 *rxbuf, int len)
{ {
struct imx_lpi2c_reg *regs = (struct imx_lpi2c_reg *)devfdt_get_addr(bus);
lpi2c_status_t result = LPI2C_SUCESS; lpi2c_status_t result = LPI2C_SUCESS;
u32 val; u32 val;
ulong start_time = get_timer(0); ulong start_time = get_timer(0);
@ -153,16 +157,25 @@ static int bus_i2c_receive(struct imx_lpi2c_reg *regs, u8 *rxbuf, int len)
return result; return result;
} }
static int bus_i2c_start(struct imx_lpi2c_reg *regs, u8 addr, u8 dir) static int bus_i2c_start(struct udevice *bus, u8 addr, u8 dir)
{ {
lpi2c_status_t result; lpi2c_status_t result;
struct imx_lpi2c_reg *regs =
(struct imx_lpi2c_reg *)devfdt_get_addr(bus);
u32 val; u32 val;
result = imx_lpci2c_check_busy_bus(regs); result = imx_lpci2c_check_busy_bus(regs);
if (result) { if (result) {
debug("i2c: start check busy bus: 0x%x\n", result); debug("i2c: start check busy bus: 0x%x\n", result);
/* Try to init the lpi2c then check the bus busy again */
bus_i2c_init(bus, 100000);
result = imx_lpci2c_check_busy_bus(regs);
if (result) {
printf("i2c: Error check busy bus: 0x%x\n", result);
return result; return result;
} }
}
/* clear all status flags */ /* clear all status flags */
writel(0x7f00, &regs->msr); writel(0x7f00, &regs->msr);
/* turn off auto-stop condition */ /* turn off auto-stop condition */
@ -181,9 +194,11 @@ static int bus_i2c_start(struct imx_lpi2c_reg *regs, u8 addr, u8 dir)
return result; return result;
} }
static int bus_i2c_stop(struct imx_lpi2c_reg *regs) static int bus_i2c_stop(struct udevice *bus)
{ {
lpi2c_status_t result; lpi2c_status_t result;
struct imx_lpi2c_reg *regs =
(struct imx_lpi2c_reg *)devfdt_get_addr(bus);
u32 status; u32 status;
ulong start_time; ulong start_time;
@ -217,28 +232,28 @@ static int bus_i2c_stop(struct imx_lpi2c_reg *regs)
return result; return result;
} }
static int bus_i2c_read(struct imx_lpi2c_reg *regs, u32 chip, u8 *buf, int len) static int bus_i2c_read(struct udevice *bus, u32 chip, u8 *buf, int len)
{ {
lpi2c_status_t result; lpi2c_status_t result;
result = bus_i2c_start(regs, chip, 1); result = bus_i2c_start(bus, chip, 1);
if (result) if (result)
return result; return result;
result = bus_i2c_receive(regs, buf, len); result = bus_i2c_receive(bus, buf, len);
if (result) if (result)
return result; return result;
return result; return result;
} }
static int bus_i2c_write(struct imx_lpi2c_reg *regs, u32 chip, u8 *buf, int len) static int bus_i2c_write(struct udevice *bus, u32 chip, u8 *buf, int len)
{ {
lpi2c_status_t result; lpi2c_status_t result;
result = bus_i2c_start(regs, chip, 0); result = bus_i2c_start(bus, chip, 0);
if (result) if (result)
return result; return result;
result = bus_i2c_send(regs, buf, len); result = bus_i2c_send(bus, buf, len);
if (result) if (result)
return result; return result;
@ -353,18 +368,16 @@ static int bus_i2c_init(struct udevice *bus, int speed)
static int imx_lpi2c_probe_chip(struct udevice *bus, u32 chip, static int imx_lpi2c_probe_chip(struct udevice *bus, u32 chip,
u32 chip_flags) u32 chip_flags)
{ {
struct imx_lpi2c_reg *regs;
lpi2c_status_t result; lpi2c_status_t result;
regs = (struct imx_lpi2c_reg *)devfdt_get_addr(bus); result = bus_i2c_start(bus, chip, 0);
result = bus_i2c_start(regs, chip, 0);
if (result) { if (result) {
bus_i2c_stop(regs); bus_i2c_stop(bus);
bus_i2c_init(bus, 100000); bus_i2c_init(bus, 100000);
return result; return result;
} }
result = bus_i2c_stop(regs); result = bus_i2c_stop(bus);
if (result) if (result)
bus_i2c_init(bus, 100000); bus_i2c_init(bus, 100000);
@ -373,16 +386,14 @@ static int imx_lpi2c_probe_chip(struct udevice *bus, u32 chip,
static int imx_lpi2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs) static int imx_lpi2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
{ {
struct imx_lpi2c_reg *regs;
int ret = 0, ret_stop; int ret = 0, ret_stop;
regs = (struct imx_lpi2c_reg *)devfdt_get_addr(bus);
for (; nmsgs > 0; nmsgs--, msg++) { for (; nmsgs > 0; nmsgs--, msg++) {
debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len); debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
if (msg->flags & I2C_M_RD) if (msg->flags & I2C_M_RD)
ret = bus_i2c_read(regs, msg->addr, msg->buf, msg->len); ret = bus_i2c_read(bus, msg->addr, msg->buf, msg->len);
else { else {
ret = bus_i2c_write(regs, msg->addr, msg->buf, ret = bus_i2c_write(bus, msg->addr, msg->buf,
msg->len); msg->len);
if (ret) if (ret)
break; break;
@ -392,7 +403,7 @@ static int imx_lpi2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
if (ret) if (ret)
debug("i2c_write: error sending\n"); debug("i2c_write: error sending\n");
ret_stop = bus_i2c_stop(regs); ret_stop = bus_i2c_stop(bus);
if (ret_stop) if (ret_stop)
debug("i2c_xfer: stop bus error\n"); debug("i2c_xfer: stop bus error\n");