AuxXxilium/linux_dsm_epyc7002
1
0
Fork 0
mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2024-12-04 02:26:56 +07:00
Code Issues Actions Packages Projects Releases Wiki Activity

i2c: at91: Fix pinmux after devm_gpiod_get() for bus recovery

Browse Source 
devm_gpiod_get() usually calls gpio_request_enable() for non-strict pinmux
drivers. These puts the pins in GPIO mode, whithout notifying the pinctrl
driver. At this point, the I2C bus no longer owns the pins. To mux the
pins back to the I2C bus, we use the pinctrl driver to change the state
of the pins to GPIO, before using devm_gpiod_get(). After the pins are
received as GPIOs, we switch theer pinctrl state back to the default
one,

Fixes: d3d3fdcc4c ("i2c: at91: implement i2c bus recovery")
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
This commit is contained in:
Codrin Ciubotariu 2020-04-15 10:06:43 +03:00 committed by Wolfram Sang
parent 2f5a55c52c
commit 7d66976fe7
1 changed files with 17 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
drivers/i2c/busses/i2c-at91-master.c
View File

@ -845,6 +845,18 @@ static int at91_init_twi_recovery_info(struct platform_device *pdev,
PINCTRL_STATE_DEFAULT);
dev->pinctrl_pins_gpio = pinctrl_lookup_state(dev->pinctrl,
"gpio");
if (IS_ERR(dev->pinctrl_pins_default) ||
IS_ERR(dev->pinctrl_pins_gpio)) {
dev_info(&pdev->dev, "pinctrl states incomplete for recovery\n");
return -EINVAL;
}
/*
* pins will be taken as GPIO, so we might as well inform pinctrl about
* this and move the state to GPIO
*/
pinctrl_select_state(dev->pinctrl, dev->pinctrl_pins_gpio);
rinfo->sda_gpiod = devm_gpiod_get(&pdev->dev, "sda", GPIOD_IN);
if (PTR_ERR(rinfo->sda_gpiod) == -EPROBE_DEFER)
return -EPROBE_DEFER;
@ -855,9 +867,7 @@ static int at91_init_twi_recovery_info(struct platform_device *pdev,
return -EPROBE_DEFER;
if (IS_ERR(rinfo->sda_gpiod) ||
IS_ERR(rinfo->scl_gpiod) ||
IS_ERR(dev->pinctrl_pins_default) ||
IS_ERR(dev->pinctrl_pins_gpio)) {
IS_ERR(rinfo->scl_gpiod)) {
dev_info(&pdev->dev, "recovery information incomplete\n");
if (!IS_ERR(rinfo->sda_gpiod)) {
gpiod_put(rinfo->sda_gpiod);
@ -867,9 +877,13 @@ static int at91_init_twi_recovery_info(struct platform_device *pdev,
gpiod_put(rinfo->scl_gpiod);
rinfo->scl_gpiod = NULL;
}
pinctrl_select_state(dev->pinctrl, dev->pinctrl_pins_default);
return -EINVAL;
}
/* change the state of the pins back to their default state */
pinctrl_select_state(dev->pinctrl, dev->pinctrl_pins_default);
dev_info(&pdev->dev, "using scl, sda for recovery\n");
rinfo->prepare_recovery = at91_prepare_twi_recovery;