[U-Boot] [PATCH v2 07/11] dm: imx: Add error checking to setup_i2c()

[Igor Grinberg]

Hi Simon,

On 09/17/14 06:51, Simon Glass wrote:
> Since this function can fail, check its return value.
> 
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
> 
> Changes in v2:
> - Add new patch to add error checking to setup_i2c()
> 
>  arch/arm/imx-common/i2c-mxv7.c            | 24 ++++++++++++++++-----
>  arch/arm/include/asm/imx-common/mxc_i2c.h |  4 ++--
>  board/compulab/cm_fx6/cm_fx6.c            | 35 +++++++++++++++++++++----------
>  3 files changed, 45 insertions(+), 18 deletions(-)
> 
> diff --git a/arch/arm/imx-common/i2c-mxv7.c b/arch/arm/imx-common/i2c-mxv7.c
> index a580873..70cff5c 100644
> --- a/arch/arm/imx-common/i2c-mxv7.c
> +++ b/arch/arm/imx-common/i2c-mxv7.c
> @@ -69,15 +69,29 @@ static void * const i2c_bases[] = {
>  };
>  
>  /* i2c_index can be from 0 - 2 */
> -void setup_i2c(unsigned i2c_index, int speed, int slave_addr,
> -		struct i2c_pads_info *p)
> +int setup_i2c(unsigned i2c_index, int speed, int slave_addr,
> +	      struct i2c_pads_info *p)
>  {
> +	int ret;
> +
>  	if (i2c_index >= ARRAY_SIZE(i2c_bases))
> -		return;
> +		return -EINVAL;
>  	/* Enable i2c clock */
> -	enable_i2c_clk(1, i2c_index);
> +	ret = enable_i2c_clk(1, i2c_index);
> +	if (ret)
> +		goto err_clk;
> +
>  	/* Make sure bus is idle */
> -	force_idle_bus(p);
> +	ret = force_idle_bus(p);
> +	if (ret)
> +		goto err_idle;
> +
>  	bus_i2c_init(i2c_bases[i2c_index], speed, slave_addr,
>  			force_idle_bus, p);
> +
> +	return 0;
> +
> +err_idle:
> +err_clk:
> +	return ret;
>  }
> diff --git a/arch/arm/include/asm/imx-common/mxc_i2c.h b/arch/arm/include/asm/imx-common/mxc_i2c.h
> index 182c2f3..af86163 100644
> --- a/arch/arm/include/asm/imx-common/mxc_i2c.h
> +++ b/arch/arm/include/asm/imx-common/mxc_i2c.h
> @@ -52,8 +52,8 @@ struct i2c_pads_info {
>  					&mx6q_##name : &mx6s_##name
>  #endif
>  
> -void setup_i2c(unsigned i2c_index, int speed, int slave_addr,
> -		struct i2c_pads_info *p);
> +int setup_i2c(unsigned i2c_index, int speed, int slave_addr,
> +	      struct i2c_pads_info *p);
>  void bus_i2c_init(void *base, int speed, int slave_addr,
>  		int (*idle_bus_fn)(void *p), void *p);
>  int bus_i2c_read(void *base, uchar chip, uint addr, int alen, uchar *buf,
> diff --git a/board/compulab/cm_fx6/cm_fx6.c b/board/compulab/cm_fx6/cm_fx6.c
> index fdb8ebf..62c625a 100644
> --- a/board/compulab/cm_fx6/cm_fx6.c
> +++ b/board/compulab/cm_fx6/cm_fx6.c
> @@ -69,7 +69,7 @@ static iomux_v3_cfg_t const sata_pads[] = {
>  	IOMUX_PADS(PAD_EIM_BCLK__GPIO6_IO31   | MUX_PAD_CTRL(NO_PAD_CTRL)),
>  };
>  
> -static void cm_fx6_setup_issd(void)
> +static int cm_fx6_setup_issd(void)
>  {
>  	SETUP_IOMUX_PADS(sata_pads);
>  	/* Make sure this gpio has logical 0 value */
> @@ -79,14 +79,18 @@ static void cm_fx6_setup_issd(void)
>  	cm_fx6_sata_power(0);
>  	mdelay(250);
>  	cm_fx6_sata_power(1);
> +
> +	return 0;
>  }
>  
>  #define CM_FX6_SATA_INIT_RETRIES	10
>  int sata_initialize(void)
>  {
> -	int err, i;
> +	int err, i, ret;
>  
> -	cm_fx6_setup_issd();
> +	ret = cm_fx6_setup_issd();
> +	if (ret)
> +		return ret;

Hmm.. cm-fx6 may have iSSD not assembled and in this case
it has bypasses for a (m)SATA socket on the baseboard.
The socketed device of course is not controlled by those GPIOs.
Therefore, I think, it would be incorrect to fail the boot process
if there is a problem with an iSSD GPIO...
Instead a warning message will be enough. Something like:

ret = cm_fx6_setup_issd();
if (ret)
	printf("Warning: iSSD setup failed!\n");

and then continue to the rest of SATA init.

>  	for (i = 0; i < CM_FX6_SATA_INIT_RETRIES; i++) {
>  		err = setup_sata();
>  		if (err) {
> @@ -141,14 +145,25 @@ I2C_PADS(i2c2_pads,
>  	 IMX_GPIO_NR(1, 6));
>  
>  
> -static void cm_fx6_setup_i2c(void)
> +static int cm_fx6_setup_i2c(void)
>  {
> -	setup_i2c(0, CONFIG_SYS_I2C_SPEED, 0x7f, I2C_PADS_INFO(i2c0_pads));
> -	setup_i2c(1, CONFIG_SYS_I2C_SPEED, 0x7f, I2C_PADS_INFO(i2c1_pads));
> -	setup_i2c(2, CONFIG_SYS_I2C_SPEED, 0x7f, I2C_PADS_INFO(i2c2_pads));
> +	int ret;
> +
> +	ret = setup_i2c(0, CONFIG_SYS_I2C_SPEED, 0x7f,
> +			I2C_PADS_INFO(i2c0_pads));
> +	if (!ret) {
> +		ret = setup_i2c(1, CONFIG_SYS_I2C_SPEED, 0x7f,
> +				I2C_PADS_INFO(i2c1_pads));
> +	}
> +	if (!ret) {
> +		ret = setup_i2c(2, CONFIG_SYS_I2C_SPEED, 0x7f,
> +				I2C_PADS_INFO(i2c2_pads));
> +	}

Almost same here, the fact that one of the (or even all) i2c buses
fails to initialize, should not lead to hang()...
The decision if this is a critical error or not should be decided
by the board code.
In this case, this is not a critical error and if one of the buses
fails to initialize, the others should still try.
So, here also, a warning message would be appropriate instead of
abort.

> +
> +	return ret;
>  }
>  #else
> -static void cm_fx6_setup_i2c(void) { }
> +static int cm_fx6_setup_i2c(void) { return 0; }
>  #endif
>  
>  #ifdef CONFIG_USB_EHCI_MX6
> @@ -411,9 +426,7 @@ int board_init(void)
>  {
>  	gd->bd->bi_boot_params = PHYS_SDRAM_1 + 0x100;
>  	cm_fx6_setup_gpmi_nand();
> -	cm_fx6_setup_i2c();
> -
> -	return 0;
> +	return cm_fx6_setup_i2c();

Same here, on cm-fx6, i2c is not that critical to U-Boot boot
process, and should not lead to hang().

>  }
>  
>  int checkboard(void)
> 

-- 
Regards,
Igor.