Re: [U-Boot] [PATCH 06/10] dm: imx: Use gpio_request() to request GPIOs

Hi Igor,

On 15 September 2014 11:13, Igor Grinberg grinberg@compulab.co.il wrote:

Hi Simon,

On 09/15/14 15:57, Simon Glass wrote:

...

GPIOs should be requested before use. Without this, driver model will not permit the GPIO to be used.

Right. That should have been done from the start... Sorry for that... A question below though..

...

Signed-off-by: Simon Glass sjg@chromium.org

arch/arm/imx-common/i2c-mxv7.c | 14 ++++++++++++++ board/compulab/cm_fx6/cm_fx6.c | 9 +++++++++ board/compulab/cm_fx6/common.c | 3 +++ 3 files changed, 26 insertions(+)

diff --git a/arch/arm/imx-common/i2c-mxv7.c b/arch/arm/imx-common/i2c-mxv7.c index a580873..7cea024 100644 --- a/arch/arm/imx-common/i2c-mxv7.c +++ b/arch/arm/imx-common/i2c-mxv7.c @@ -4,6 +4,7 @@

• SPDX-License-Identifier: GPL-2.0+

*/ #include <common.h> +#include <malloc.h> #include <asm/arch/clock.h> #include <asm/arch/imx-regs.h> #include <asm/errno.h> @@ -72,8 +73,21 @@ static void * const i2c_bases[] = { void setup_i2c(unsigned i2c_index, int speed, int slave_addr, struct i2c_pads_info *p) {

• char *name;
  

• if (i2c_index >= ARRAY_SIZE(i2c_bases))
          return;
  

• name = malloc(9);
  

• assert(name);
  

• sprintf(name, "i2c_sda%d", i2c_index);
  

• gpio_request(p->sda.gp, name);
  

• name = malloc(9);
  

• assert(name);
  

• sprintf(name, "i2c_scl%d", i2c_index);
  

• gpio_request(p->scl.gp, name);
  

• /* Enable i2c clock */
  enable_i2c_clk(1, i2c_index);
  /* Make sure bus is idle */
  

diff --git a/board/compulab/cm_fx6/cm_fx6.c b/board/compulab/cm_fx6/cm_fx6.c index fdb8ebf..80a123d 100644 --- a/board/compulab/cm_fx6/cm_fx6.c +++ b/board/compulab/cm_fx6/cm_fx6.c @@ -71,8 +71,15 @@ static iomux_v3_cfg_t const sata_pads[] = {

static void cm_fx6_setup_issd(void) {

• int i;
  

• SETUP_IOMUX_PADS(sata_pads);
  

• for (i = 0; i < ARRAY_SIZE(cm_fx6_issd_gpios); i++)
  

•         gpio_request(cm_fx6_issd_gpios[i], "sata");
  

• /* Make sure this gpio has logical 0 value */
  

• gpio_request(CM_FX6_SATA_PWLOSS_INT, "sata_pwloss_int");
  gpio_direction_output(CM_FX6_SATA_PWLOSS_INT, 0);
  udelay(100);
  
  

@@ -167,6 +174,7 @@ static int cm_fx6_usb_hub_reset(void) }

  SETUP_IOMUX_PAD(PAD_SD3_RST__GPIO7_IO08 | MUX_PAD_CTRL(NO_PAD_CTRL));

• gpio_request(CM_FX6_USB_HUB_RST, "usb_hub_rst");
  gpio_direction_output(CM_FX6_USB_HUB_RST, 0);
  udelay(10);
  gpio_direction_output(CM_FX6_USB_HUB_RST, 1);
  

@@ -324,6 +332,7 @@ int board_eth_init(bd_t *bis)

  SETUP_IOMUX_PADS(enet_pads);
  /* phy reset */

• gpio_request(CM_FX6_ENET_NRST, "enet_nrst");
  gpio_direction_output(CM_FX6_ENET_NRST, 0);
  udelay(500);
  gpio_set_value(CM_FX6_ENET_NRST, 1);
  

diff --git a/board/compulab/cm_fx6/common.c b/board/compulab/cm_fx6/common.c index 1f39679..562313b 100644 --- a/board/compulab/cm_fx6/common.c +++ b/board/compulab/cm_fx6/common.c @@ -79,6 +79,9 @@ void cm_fx6_set_ecspi_iomux(void)

int board_spi_cs_gpio(unsigned bus, unsigned cs) { +#ifndef CONFIG_SPL_BUILD

• gpio_request(CM_FX6_ECSPI_BUS0_CS0, "ecspi_bus0_cs0");
  

+#endif return (bus == 0 && cs == 0) ? (CM_FX6_ECSPI_BUS0_CS0) : -1; } #endif

In all the above gpio_request() calls, I think we should check for the return value. Because after patch 8 in the series it can fail if if someone double requests the same gpio.

That's true, although for a particular board you presumably know what you are doing. The problem happens more when we move this sort of thing to drivers, and there is a conflict.

In some cases there is not way to report an error (void functions), and in others it needs additional plumbing. But I agree we should start to fix this sort of thing.

Regards, Simon