scottk/OpenCellular
1
0
Fork 0
mirror of https://github.com/Telecominfraproject/OpenCellular.git synced 2026-01-09 17:11:42 +00:00
Code Issues Packages Projects Releases Wiki Activity

snow: re-factor i2c init

Browse Source 
This re-factors i2c initialization to simplify it and make it follow
the correct order. This is intended to fix a bug where the I2C lines
could be driven low for no good reason on EC startup, potentially
causing issues with other devices.

The ordering should be:
1. Setup pins as inputs on EC startup.
2. Initialize I2C module(s)
3. Re-configure pins as alternate function.

(Thanks to dianders for pointing out this bug)

Signed-off-by: David Hendricks <dhendrix@chromium.org>
BRANCH=snow
BUG=chrome-os-partner:13443
TEST=Tested by examining scope traces during EC reboot

Change-Id: Ibb845f3fd538da387132b1c822929f8613de077d
Reviewed-on: https://gerrit.chromium.org/gerrit/31647
Commit-Ready: David Hendricks <dhendrix@chromium.org>
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Tested-by: David Hendricks <dhendrix@chromium.org>
Reviewed-by: Doug Anderson <dianders@chromium.org>
This commit is contained in:
David Hendricks
2012-08-28 14:55:42 -07:00
committed by Gerrit
parent 3efa44c57b
commit 7a9dc9c0ec
3 changed files with 43 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

42
board/snow/board.c
View File

@@ -60,7 +60,14 @@ const struct gpio_info gpio_list[GPIO_COUNT] = {
/* Other inputs */
{"AC_PWRBTN_L", GPIO_A, (1<<0), GPIO_INT_BOTH, NULL},
{"SPI1_NSS", GPIO_A, (1<<4), GPIO_DEFAULT, NULL},
/*
* I2C pins should be configured as inputs until I2C module is
* initialized. This will avoid driving the lines unintentionally.
*/
{"I2C1_SCL", GPIO_B, (1<<6), GPIO_INPUT, NULL},
{"I2C1_SDA", GPIO_B, (1<<7), GPIO_INPUT, NULL},
{"I2C2_SCL", GPIO_B, (1<<10), GPIO_INPUT, NULL},
{"I2C2_SDA", GPIO_B, (1<<11), GPIO_INPUT, NULL},
/* Outputs */
{"AC_STATUS", GPIO_A, (1<<5), GPIO_DEFAULT, NULL},
{"SPI1_MISO", GPIO_A, (1<<6), GPIO_DEFAULT, NULL},
@@ -114,20 +121,6 @@ void configure_board(void)
STM32_GPIO_AFIO_MAPR = (STM32_GPIO_AFIO_MAPR & ~(0x3 << 8))
| (1 << 8);
/*
* I2C SCL/SDA on PB10-11 and PB6-7, bi-directional, no pull-up/down,
* initialized as hi-Z until alt. function is set
*/
val = STM32_GPIO_CRH_OFF(GPIO_B) & ~0x0000ff00;
val |= 0x0000dd00;
STM32_GPIO_CRH_OFF(GPIO_B) = val;
val = STM32_GPIO_CRL_OFF(GPIO_B) & ~0xff000000;
val |= 0xdd000000;
STM32_GPIO_CRL_OFF(GPIO_B) = val;
STM32_GPIO_BSRR_OFF(GPIO_B) |= (1<<11) | (1<<10) | (1<<7) | (1<<6);
/*
* Set alternate function for USART1. For alt. function input
* the port is configured in either floating or pull-up/down
@@ -149,6 +142,25 @@ void configure_board(void)
gpio_set_level(GPIO_EC_INT, 1);
}
/* GPIO configuration to be done after I2C module init */
void board_i2c_post_init(int port)
{
uint32_t val;
/* enable alt. function (open-drain) */
if (port == STM32_I2C1_PORT) {
/* I2C1 is on PB6-7 */
val = STM32_GPIO_CRL_OFF(GPIO_B) & ~0xff000000;
val |= 0xdd000000;
STM32_GPIO_CRL_OFF(GPIO_B) = val;
} else if (port == STM32_I2C2_PORT) {
/* I2C2 is on PB10-11 */
val = STM32_GPIO_CRH_OFF(GPIO_B) & ~0x0000ff00;
val |= 0x0000dd00;
STM32_GPIO_CRH_OFF(GPIO_B) = val;
}
}
void configure_board_late(void)
{
#ifdef CONFIG_AC_POWER_STATUS

4
board/snow/board.h
View File

@@ -84,6 +84,10 @@ enum gpio_signal {
/* Other inputs */
GPIO_AC_PWRBTN_L,
GPIO_SPI1_NSS,
GPIO_I2C1_SCL,
GPIO_I2C1_SDA,
GPIO_I2C2_SCL,
GPIO_I2C2_SDA,
/* Outputs */
GPIO_AC_STATUS,
GPIO_SPI1_MISO,

12
chip/stm32/i2c.c
View File

@@ -352,6 +352,14 @@ static void i2c_error_handler(int port)
static void i2c2_error_interrupt(void) { i2c_error_handler(I2C2); }
DECLARE_IRQ(STM32_IRQ_I2C2_ER, i2c2_error_interrupt, 2);
/* board-specific setup for post-I2C module init */
void __board_i2c_post_init(int port)
{
}
void board_i2c_post_init(int port)
__attribute__((weak, alias("__board_i2c_post_init")));
static int i2c_init2(void)
{
/* enable I2C2 clock */
@@ -381,6 +389,8 @@ static int i2c_init2(void)
task_enable_irq(STM32_IRQ_I2C2_EV);
task_enable_irq(STM32_IRQ_I2C2_ER);
board_i2c_post_init(I2C2);
CPUTS("done\n");
return EC_SUCCESS;
}
@@ -411,6 +421,8 @@ static int i2c_init1(void)
task_enable_irq(STM32_IRQ_I2C1_EV);
task_enable_irq(STM32_IRQ_I2C1_ER);
board_i2c_post_init(I2C1);
return EC_SUCCESS;
}