2023-09-26 15:54:03

by Duje Mihanović

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Subject: [PATCH RFC v2 4/6] ARM: pxa: Convert reset driver to GPIO descriptors

The PXA reset driver still uses the legacy GPIO interface for
configuring and asserting the reset pin.

Convert it to use the GPIO descriptor interface.

Signed-off-by: Duje Mihanović <[email protected]>
---
arch/arm/mach-pxa/reset.c | 39 +++++++++++++--------------------------
arch/arm/mach-pxa/reset.h | 3 +--
arch/arm/mach-pxa/spitz.c | 6 +++++-
3 files changed, 19 insertions(+), 29 deletions(-)

diff --git a/arch/arm/mach-pxa/reset.c b/arch/arm/mach-pxa/reset.c
index 27293549f8ad..dfcd6c45398d 100644
--- a/arch/arm/mach-pxa/reset.c
+++ b/arch/arm/mach-pxa/reset.c
@@ -2,7 +2,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
#include <linux/io.h>
#include <asm/proc-fns.h>
#include <asm/system_misc.h>
@@ -14,33 +14,20 @@

static void do_hw_reset(void);

-static int reset_gpio = -1;
+static struct gpio_desc *reset_gpio = NULL;

-int init_gpio_reset(int gpio, int output, int level)
+int init_gpio_reset(int output, int level)
{
- int rc;
-
- rc = gpio_request(gpio, "reset generator");
- if (rc) {
- printk(KERN_ERR "Can't request reset_gpio\n");
- goto out;
+ reset_gpio = gpiod_get(NULL, "reset generator", GPIOD_ASIS);
+ if (IS_ERR(reset_gpio)) {
+ pr_err("Can't request reset_gpio: %pe\n", reset_gpio);
+ return PTR_ERR(reset_gpio);
}

if (output)
- rc = gpio_direction_output(gpio, level);
+ return gpiod_direction_output(reset_gpio, level);
else
- rc = gpio_direction_input(gpio);
- if (rc) {
- printk(KERN_ERR "Can't configure reset_gpio\n");
- gpio_free(gpio);
- goto out;
- }
-
-out:
- if (!rc)
- reset_gpio = gpio;
-
- return rc;
+ return gpiod_direction_input(reset_gpio);
}

/*
@@ -50,16 +37,16 @@ int init_gpio_reset(int gpio, int output, int level)
*/
static void do_gpio_reset(void)
{
- BUG_ON(reset_gpio == -1);
+ BUG_ON(IS_ERR(reset_gpio));

/* drive it low */
- gpio_direction_output(reset_gpio, 0);
+ gpiod_direction_output(reset_gpio, 0);
mdelay(2);
/* rising edge or drive high */
- gpio_set_value(reset_gpio, 1);
+ gpiod_set_value(reset_gpio, 1);
mdelay(2);
/* falling edge */
- gpio_set_value(reset_gpio, 0);
+ gpiod_set_value(reset_gpio, 0);

/* give it some time */
mdelay(10);
diff --git a/arch/arm/mach-pxa/reset.h b/arch/arm/mach-pxa/reset.h
index 963dd190bc13..5864f61a0e94 100644
--- a/arch/arm/mach-pxa/reset.h
+++ b/arch/arm/mach-pxa/reset.h
@@ -13,10 +13,9 @@ extern void pxa_register_wdt(unsigned int reset_status);

/**
* init_gpio_reset() - register GPIO as reset generator
- * @gpio: gpio nr
* @output: set gpio as output instead of input during normal work
* @level: output level
*/
-extern int init_gpio_reset(int gpio, int output, int level);
+extern int init_gpio_reset(int output, int level);

#endif /* __ASM_ARCH_RESET_H */
diff --git a/arch/arm/mach-pxa/spitz.c b/arch/arm/mach-pxa/spitz.c
index 616305978727..94bcb187713b 100644
--- a/arch/arm/mach-pxa/spitz.c
+++ b/arch/arm/mach-pxa/spitz.c
@@ -1024,9 +1024,13 @@ static void spitz_restart(enum reboot_mode mode, const char *cmd)
spitz_poweroff();
}

+GPIO_LOOKUP_SINGLE(spitz_reset_gpio_table, NULL, "pxa-gpio",
+ SPITZ_GPIO_ON_RESET, "reset generator", GPIO_ACTIVE_HIGH);
+
static void __init spitz_init(void)
{
- init_gpio_reset(SPITZ_GPIO_ON_RESET, 1, 0);
+ gpiod_add_lookup_table(&spitz_reset_gpio_table);
+ init_gpio_reset(1, 0);
pm_power_off = spitz_poweroff;

PMCR = 0x00;

--
2.42.0



2023-09-26 16:24:27

by Andy Shevchenko

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Subject: Re: [PATCH RFC v2 4/6] ARM: pxa: Convert reset driver to GPIO descriptors

On Tue, Sep 26, 2023 at 05:46:25PM +0200, Duje Mihanović wrote:
> The PXA reset driver still uses the legacy GPIO interface for
> configuring and asserting the reset pin.
>
> Convert it to use the GPIO descriptor interface.

...

> +static struct gpio_desc *reset_gpio = NULL;

Assignment is not needed, it's guaranteed to be NULL by the C standard.

--
With Best Regards,
Andy Shevchenko


2023-09-27 01:20:08

by Linus Walleij

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Subject: Re: [PATCH RFC v2 4/6] ARM: pxa: Convert reset driver to GPIO descriptors

On Tue, Sep 26, 2023 at 5:46 PM Duje Mihanović <[email protected]> wrote:

> The PXA reset driver still uses the legacy GPIO interface for
> configuring and asserting the reset pin.
>
> Convert it to use the GPIO descriptor interface.
>
> Signed-off-by: Duje Mihanović <[email protected]>

Looks OK to me, there are details I would do differently,
but hey: I'm just happy this gets done.
Acked-by: Linus Walleij <[email protected]>

Yours,
Linus Walleij