[PATCH RFC v4 0/6] ARM: pxa: GPIO descriptor conversions

[PATCH RFC v4 0/6] ARM: pxa: GPIO descriptor conversions

[Duje Mihanović]

Hello,

Small series to convert some of the board files in the mach-pxa directory
to use the new GPIO descriptor interface.

Most notably, the am200epd, am300epd and Spitz matrix keypad among
others are not converted in this series.

Signed-off-by: Duje Mihanović <duje.mihanovic@skole.hr>
---
Changes in v4:
- Address maintainer comments:
  - Move wait_for_sync() from spitz.c to driver
  - Register LED platform device before getting its gpiod-s
- Add Linus' Reviewed-by
- Link to v3: https://lore.kernel.org/r/20230929-pxa-gpio-v3-0-af8d5e5d1f34@skole.hr

Changes in v3:
- Address maintainer comments:
  - Use GPIO_LOOKUP_IDX for LEDs
  - Drop unnecessary NULL assignments
  - Don't give up on *all* SPI devices if hsync cannot be set up
- Add Linus' Acked-by
- Link to v2: https://lore.kernel.org/r/20230926-pxa-gpio-v2-0-984464d165dd@skole.hr

Changes in v2:
- Address maintainer comments:
  - Change mentions of function to function()
  - Drop cast in OHCI driver dev_warn() call
  - Use %pe in OHCI and reset drivers
  - Use GPIO _optional() API in OHCI driver
  - Drop unnecessary not-null check in OHCI driver
  - Use pr_err() instead of printk() in reset driver
- Rebase on v6.6-rc3
- Link to v1: https://lore.kernel.org/r/20230924-pxa-gpio-v1-0-2805b87d8894@skole.hr

---
Duje Mihanović (6):
      ARM: pxa: Convert Spitz OHCI to GPIO descriptors
      ARM: pxa: Convert Spitz LEDs to GPIO descriptors
      ARM: pxa: Convert Spitz CF power control to GPIO descriptors
      ARM: pxa: Convert reset driver to GPIO descriptors
      ARM: pxa: Convert gumstix Bluetooth to GPIO descriptors
      input: ads7846: Move wait_for_sync() logic to driver

 arch/arm/mach-pxa/gumstix.c         | 24 +++++++------
 arch/arm/mach-pxa/reset.c           | 39 +++++++--------------
 arch/arm/mach-pxa/reset.h           |  3 +-
 arch/arm/mach-pxa/spitz.c           | 69 +++++++++++++++++++++++++------------
 drivers/input/touchscreen/ads7846.c | 22 ++++++++----
 drivers/usb/host/ohci-pxa27x.c      |  7 ++++
 include/linux/spi/ads7846.h         |  1 -
 7 files changed, 96 insertions(+), 69 deletions(-)
---
base-commit: 6465e260f48790807eef06b583b38ca9789b6072
change-id: 20230807-pxa-gpio-3ce25d574814

Best regards,
-- 
Duje Mihanović <duje.mihanovic@skole.hr>

[PATCH RFC v4 1/6] ARM: pxa: Convert Spitz OHCI to GPIO descriptors

[Duje Mihanović]

Sharp's Spitz board still uses the legacy GPIO interface for controlling
a GPIO pin related to the USB host controller.

Convert this function to use the new GPIO descriptor interface.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Duje Mihanović <duje.mihanovic@skole.hr>
---
 arch/arm/mach-pxa/spitz.c      | 13 ++++++-------
 drivers/usb/host/ohci-pxa27x.c |  7 +++++++
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/arch/arm/mach-pxa/spitz.c b/arch/arm/mach-pxa/spitz.c
index cc691b199429..535e2b2e997b 100644
--- a/arch/arm/mach-pxa/spitz.c
+++ b/arch/arm/mach-pxa/spitz.c
@@ -649,23 +649,22 @@ static inline void spitz_mmc_init(void) {}
  * USB Host
  ******************************************************************************/
 #if defined(CONFIG_USB_OHCI_HCD) || defined(CONFIG_USB_OHCI_HCD_MODULE)
+GPIO_LOOKUP_SINGLE(spitz_usb_host_gpio_table, "pxa27x-ohci", "gpio-pxa",
+		SPITZ_GPIO_USB_HOST, "usb-host", GPIO_ACTIVE_LOW);
+
 static int spitz_ohci_init(struct device *dev)
 {
-	int err;
-
-	err = gpio_request(SPITZ_GPIO_USB_HOST, "USB_HOST");
-	if (err)
-		return err;
+	gpiod_add_lookup_table(&spitz_usb_host_gpio_table);
 
 	/* Only Port 2 is connected, setup USB Port 2 Output Control Register */
 	UP2OCR = UP2OCR_HXS | UP2OCR_HXOE | UP2OCR_DPPDE | UP2OCR_DMPDE;
 
-	return gpio_direction_output(SPITZ_GPIO_USB_HOST, 1);
+	return 0;
 }
 
 static void spitz_ohci_exit(struct device *dev)
 {
-	gpio_free(SPITZ_GPIO_USB_HOST);
+	gpiod_remove_lookup_table(&spitz_usb_host_gpio_table);
 }
 
 static struct pxaohci_platform_data spitz_ohci_platform_data = {
diff --git a/drivers/usb/host/ohci-pxa27x.c b/drivers/usb/host/ohci-pxa27x.c
index 357d9aee38a3..b70d452ca7c2 100644
--- a/drivers/usb/host/ohci-pxa27x.c
+++ b/drivers/usb/host/ohci-pxa27x.c
@@ -121,6 +121,7 @@ struct pxa27x_ohci {
 	void __iomem	*mmio_base;
 	struct regulator *vbus[3];
 	bool		vbus_enabled[3];
+	struct gpio_desc *usb_host;
 };
 
 #define to_pxa27x_ohci(hcd)	(struct pxa27x_ohci *)(hcd_to_ohci(hcd)->priv)
@@ -447,6 +448,10 @@ static int ohci_hcd_pxa27x_probe(struct platform_device *pdev)
 	pxa_ohci = to_pxa27x_ohci(hcd);
 	pxa_ohci->clk = usb_clk;
 	pxa_ohci->mmio_base = (void __iomem *)hcd->regs;
+	pxa_ohci->usb_host = gpiod_get_optional(&pdev->dev, "usb-host", GPIOD_OUT_LOW);
+	if (IS_ERR(pxa_ohci->usb_host))
+		dev_warn(&pdev->dev, "failed to get USB host GPIO with %pe\n",
+				pxa_ohci->usb_host);
 
 	for (i = 0; i < 3; ++i) {
 		char name[6];
@@ -512,6 +517,8 @@ static void ohci_hcd_pxa27x_remove(struct platform_device *pdev)
 	for (i = 0; i < 3; ++i)
 		pxa27x_ohci_set_vbus_power(pxa_ohci, i, false);
 
+	gpiod_put(pxa_ohci->usb_host);
+
 	usb_put_hcd(hcd);
 }
 

-- 
2.42.0

Re: [PATCH RFC v4 1/6] ARM: pxa: Convert Spitz OHCI to GPIO descriptors

[Andy Shevchenko]

On Sun, Oct 1, 2023 at 5:13 PM Duje Mihanović <duje.mihanovic@skole.hr> wrote:
>
> Sharp's Spitz board still uses the legacy GPIO interface for controlling
> a GPIO pin related to the USB host controller.
>
> Convert this function to use the new GPIO descriptor interface.

...

> +       pxa_ohci->usb_host = gpiod_get_optional(&pdev->dev, "usb-host", GPIOD_OUT_LOW);
> +       if (IS_ERR(pxa_ohci->usb_host))
> +               dev_warn(&pdev->dev, "failed to get USB host GPIO with %pe\n",
> +                               pxa_ohci->usb_host);

Since you are using _optional() API, you need to bail out on the error
case and replace dev_warn() by dev_err(). I guess I already commented
on this. What is the rationale to not follow my comment?

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH RFC v4 1/6] ARM: pxa: Convert Spitz OHCI to GPIO descriptors

[Duje Mihanović]

On 10/1/2023 4:32 PM, Andy Shevchenko wrote:
>> +       pxa_ohci->usb_host = gpiod_get_optional(&pdev->dev, "usb-host", GPIOD_OUT_LOW);
>> +       if (IS_ERR(pxa_ohci->usb_host))
>> +               dev_warn(&pdev->dev, "failed to get USB host GPIO with %pe\n",
>> +                               pxa_ohci->usb_host);
> 
> Since you are using _optional() API, you need to bail out on the error
> case and replace dev_warn() by dev_err(). I guess I already commented
> on this. What is the rationale to not follow my comment?

I must have missed it, sorry about that. I'll be sure to do so in v5.

Regards,
Duje

[PATCH RFC v4 2/6] ARM: pxa: Convert Spitz LEDs to GPIO descriptors

[Duje Mihanović]

Sharp's Spitz board still uses the legacy GPIO interface for configuring
its two onboard LEDs.

Convert them to use the GPIO descriptor interface.

Signed-off-by: Duje Mihanović <duje.mihanovic@skole.hr>
---
 arch/arm/mach-pxa/spitz.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-pxa/spitz.c b/arch/arm/mach-pxa/spitz.c
index 535e2b2e997b..b6a4085e9fb0 100644
--- a/arch/arm/mach-pxa/spitz.c
+++ b/arch/arm/mach-pxa/spitz.c
@@ -452,16 +452,25 @@ static inline void spitz_keys_init(void) {}
  * LEDs
  ******************************************************************************/
 #if defined(CONFIG_LEDS_GPIO) || defined(CONFIG_LEDS_GPIO_MODULE)
+static struct gpiod_lookup_table spitz_led_gpio_table = {
+	.dev_id = "leds-gpio",
+	.table = {
+		GPIO_LOOKUP_IDX("pxa-gpio", SPITZ_GPIO_LED_ORANGE, NULL, 0,
+				GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP_IDX("pxa-gpio", SPITZ_GPIO_LED_GREEN, NULL, 1,
+				GPIO_ACTIVE_HIGH),
+		{ }
+	}
+};
+
 static struct gpio_led spitz_gpio_leds[] = {
 	{
 		.name			= "spitz:amber:charge",
 		.default_trigger	= "sharpsl-charge",
-		.gpio			= SPITZ_GPIO_LED_ORANGE,
 	},
 	{
 		.name			= "spitz:green:hddactivity",
 		.default_trigger	= "disk-activity",
-		.gpio			= SPITZ_GPIO_LED_GREEN,
 	},
 };
 
@@ -480,7 +489,12 @@ static struct platform_device spitz_led_device = {
 
 static void __init spitz_leds_init(void)
 {
+	gpiod_add_lookup_table(&spitz_led_gpio_table);
 	platform_device_register(&spitz_led_device);
+	spitz_gpio_leds[0].gpiod = gpiod_get_index(&spitz_led_device.dev,
+			NULL, 0, GPIOD_ASIS);
+	spitz_gpio_leds[1].gpiod = gpiod_get_index(&spitz_led_device.dev,
+			NULL, 1, GPIOD_ASIS);
 }
 #else
 static inline void spitz_leds_init(void) {}

-- 
2.42.0

Re: [PATCH RFC v4 2/6] ARM: pxa: Convert Spitz LEDs to GPIO descriptors

[Andy Shevchenko]

On Sun, Oct 1, 2023 at 5:13 PM Duje Mihanović <duje.mihanovic@skole.hr> wrote:
>
> Sharp's Spitz board still uses the legacy GPIO interface for configuring
> its two onboard LEDs.
>
> Convert them to use the GPIO descriptor interface.

...

>  static void __init spitz_leds_init(void)
>  {
> +       gpiod_add_lookup_table(&spitz_led_gpio_table);
>         platform_device_register(&spitz_led_device);
> +       spitz_gpio_leds[0].gpiod = gpiod_get_index(&spitz_led_device.dev,
> +                       NULL, 0, GPIOD_ASIS);
> +       spitz_gpio_leds[1].gpiod = gpiod_get_index(&spitz_led_device.dev,
> +                       NULL, 1, GPIOD_ASIS);
>  }

What's the point of keeping a lookup table after we got descriptors out of it?

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH RFC v4 2/6] ARM: pxa: Convert Spitz LEDs to GPIO descriptors

[Bartosz Golaszewski]

On Sun, Oct 1, 2023 at 4:35 PM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
>
> On Sun, Oct 1, 2023 at 5:13 PM Duje Mihanović <duje.mihanovic@skole.hr> wrote:
> >
> > Sharp's Spitz board still uses the legacy GPIO interface for configuring
> > its two onboard LEDs.
> >
> > Convert them to use the GPIO descriptor interface.
>
> ...
>
> >  static void __init spitz_leds_init(void)
> >  {
> > +       gpiod_add_lookup_table(&spitz_led_gpio_table);
> >         platform_device_register(&spitz_led_device);
> > +       spitz_gpio_leds[0].gpiod = gpiod_get_index(&spitz_led_device.dev,
> > +                       NULL, 0, GPIOD_ASIS);
> > +       spitz_gpio_leds[1].gpiod = gpiod_get_index(&spitz_led_device.dev,
> > +                       NULL, 1, GPIOD_ASIS);
> >  }
>
> What's the point of keeping a lookup table after we got descriptors out of it?
>

Normally the descriptors would be retrieved in drivers and so lookup
tables should stay in memory forever as static resources (just like
device-tree). We have recently added some "temporary" lookup tables to
address even worse hacks. The tables would be removed immediately
after the descriptor is retrieved simply because we used that hack in
drivers which may be unbound and re-bound resulting in adding
repeating lookup entries.

Here we're dealing with a board-file so a more classic approach of
having static lookup tables added once and never removed is in order.
So I'd leave it like this.

Bart

Re: [PATCH RFC v4 2/6] ARM: pxa: Convert Spitz LEDs to GPIO descriptors

[Linus Walleij]

On Sun, Oct 1, 2023 at 4:13 PM Duje Mihanović <duje.mihanovic@skole.hr> wrote:

> Sharp's Spitz board still uses the legacy GPIO interface for configuring
> its two onboard LEDs.
>
> Convert them to use the GPIO descriptor interface.
>
> Signed-off-by: Duje Mihanović <duje.mihanovic@skole.hr>

LGTM:
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

[PATCH RFC v4 3/6] ARM: pxa: Convert Spitz CF power control to GPIO descriptors

[Duje Mihanović]

Sharp's Spitz board still uses the legacy GPIO interface for controlling
the power supply to its CF and SD card slots.

Convert it to use the GPIO descriptor interface.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Duje Mihanović <duje.mihanovic@skole.hr>
---
 arch/arm/mach-pxa/spitz.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-pxa/spitz.c b/arch/arm/mach-pxa/spitz.c
index b6a4085e9fb0..965354e64c68 100644
--- a/arch/arm/mach-pxa/spitz.c
+++ b/arch/arm/mach-pxa/spitz.c
@@ -133,6 +133,10 @@ static unsigned long spitz_pin_config[] __initdata = {
  * Scoop GPIO expander
  ******************************************************************************/
 #if defined(CONFIG_SHARP_SCOOP) || defined(CONFIG_SHARP_SCOOP_MODULE)
+GPIO_LOOKUP_SINGLE(spitz_card_pwr_ctrl_gpio_table, "pxa2xx-mci.0",
+		"sharp-scoop", SPITZ_GPIO_CF_POWER, "cf_power",
+		GPIO_ACTIVE_HIGH);
+
 /* SCOOP Device #1 */
 static struct resource spitz_scoop_1_resources[] = {
 	[0] = {
@@ -190,6 +194,7 @@ struct platform_device spitz_scoop_2_device = {
 static void __init spitz_scoop_init(void)
 {
 	platform_device_register(&spitz_scoop_1_device);
+	gpiod_add_lookup_table(&spitz_card_pwr_ctrl_gpio_table);
 
 	/* Akita doesn't have the second SCOOP chip */
 	if (!machine_is_akita())
@@ -201,9 +206,18 @@ static void __maybe_unused spitz_card_pwr_ctrl(uint8_t enable, uint8_t new_cpr)
 {
 	unsigned short cpr;
 	unsigned long flags;
+	struct gpio_desc *cf_power;
+
+	cf_power = gpiod_get(&pxa_device_mci.dev, "cf_power", GPIOD_ASIS);
+	if (IS_ERR(cf_power)) {
+		dev_err(&pxa_device_mci.dev,
+				"failed to get power control GPIO with %ld\n",
+				PTR_ERR(cf_power));
+		return;
+	}
 
 	if (new_cpr & 0x7) {
-		gpio_set_value(SPITZ_GPIO_CF_POWER, 1);
+		gpiod_direction_output(cf_power, 1);
 		mdelay(5);
 	}
 
@@ -222,8 +236,10 @@ static void __maybe_unused spitz_card_pwr_ctrl(uint8_t enable, uint8_t new_cpr)
 
 	if (!(cpr & 0x7)) {
 		mdelay(1);
-		gpio_set_value(SPITZ_GPIO_CF_POWER, 0);
+		gpiod_direction_output(cf_power, 0);
 	}
+
+	gpiod_put(cf_power);
 }
 
 #else

-- 
2.42.0

[PATCH RFC v4 4/6] ARM: pxa: Convert reset driver to GPIO descriptors

[Duje Mihanović]

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.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Duje Mihanović <duje.mihanovic@skole.hr>
---
 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..2bfa66f99555 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;
 
-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 965354e64c68..701fba130ac4 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

Re: [PATCH RFC v4 4/6] ARM: pxa: Convert reset driver to GPIO descriptors

[Andy Shevchenko]

On Sun, Oct 1, 2023 at 5:13 PM Duje Mihanović <duje.mihanovic@skole.hr> 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.

> Acked-by: Linus Walleij <linus.walleij@linaro.org>

I dunno how.

...

> +       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);
>         }

Here you asked for the GPIO named as "reset generator-gpio(s)" (The
"(s)" part is for new bindings), but you must not use spaces in the
GPIO names. Moreover the string literal there is for labeling, and not
for matching.

...

> +GPIO_LOOKUP_SINGLE(spitz_reset_gpio_table, NULL, "pxa-gpio",

And here should be gpios. That's what you have to request, but because
of the global (device-less) nature of this, you have to be very
careful to avoid any clashes.

> +               SPITZ_GPIO_ON_RESET, "reset generator", GPIO_ACTIVE_HIGH);

...

TBH, I don't know how it is supposed to work with your current code
and if Linus really was okay with this.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH RFC v4 4/6] ARM: pxa: Convert reset driver to GPIO descriptors

[Andy Shevchenko]

On Sun, Oct 1, 2023 at 5:40 PM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
> On Sun, Oct 1, 2023 at 5:13 PM Duje Mihanović <duje.mihanovic@skole.hr> wrote:

...

> TBH, I don't know how it is supposed to work with your current code
> and if Linus really was okay with this.

Okay, it seems I have to refresh my memories about GPIO lookup tables.
First of all, we indeed require a connection ID just to match and no
matter if it has or hasn't the suffix.Second, the key is a label of
the GPIO controller according to the device driver (device tree?) and
pxa-gpio is that one. Seems it should work.


-- 
With Best Regards,
Andy Shevchenko

[PATCH RFC v4 5/6] ARM: pxa: Convert gumstix Bluetooth to GPIO descriptors

[Duje Mihanović]

Gumstix still uses the legacy GPIO interface for resetting the Bluetooth
device.

Convert it to use the GPIO descriptor interface.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Duje Mihanović <duje.mihanovic@skole.hr>
---
 arch/arm/mach-pxa/gumstix.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/arch/arm/mach-pxa/gumstix.c b/arch/arm/mach-pxa/gumstix.c
index c9f0f62187bd..14e1b9274d7a 100644
--- a/arch/arm/mach-pxa/gumstix.c
+++ b/arch/arm/mach-pxa/gumstix.c
@@ -20,8 +20,8 @@
 #include <linux/delay.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
+#include <linux/gpio/consumer.h>
 #include <linux/gpio/machine.h>
-#include <linux/gpio.h>
 #include <linux/err.h>
 #include <linux/clk.h>
 
@@ -129,6 +129,9 @@ static void gumstix_udc_init(void)
 #endif
 
 #ifdef CONFIG_BT
+GPIO_LOOKUP_SINGLE(gumstix_bt_gpio_table, "pxa2xx-uart.1", "pxa-gpio",
+		GPIO_GUMSTIX_BTRESET, "BTRST", GPIO_ACTIVE_LOW);
+
 /* Normally, the bootloader would have enabled this 32kHz clock but many
 ** boards still have u-boot 1.1.4 so we check if it has been turned on and
 ** if not, we turn it on with a warning message. */
@@ -153,24 +156,23 @@ static void gumstix_setup_bt_clock(void)
 
 static void __init gumstix_bluetooth_init(void)
 {
-	int err;
+	struct gpio_desc *desc;
+
+	gpiod_add_lookup_table(&gumstix_bt_gpio_table);
 
 	gumstix_setup_bt_clock();
 
-	err = gpio_request(GPIO_GUMSTIX_BTRESET, "BTRST");
-	if (err) {
+	desc = gpiod_get(&pxa_device_btuart.dev, "BTRST", GPIOD_OUT_HIGH);
+	if (IS_ERR(desc)) {
 		pr_err("gumstix: failed request gpio for bluetooth reset\n");
 		return;
 	}
 
-	err = gpio_direction_output(GPIO_GUMSTIX_BTRESET, 1);
-	if (err) {
-		pr_err("gumstix: can't reset bluetooth\n");
-		return;
-	}
-	gpio_set_value(GPIO_GUMSTIX_BTRESET, 0);
+	gpiod_set_value(desc, 0);
 	udelay(100);
-	gpio_set_value(GPIO_GUMSTIX_BTRESET, 1);
+	gpiod_set_value(desc, 1);
+
+	gpiod_put(desc);
 }
 #else
 static void gumstix_bluetooth_init(void)

-- 
2.42.0

Re: [PATCH RFC v4 5/6] ARM: pxa: Convert gumstix Bluetooth to GPIO descriptors

[Bartosz Golaszewski]

On Sun, Oct 1, 2023 at 4:13 PM Duje Mihanović <duje.mihanovic@skole.hr> wrote:
>
> Gumstix still uses the legacy GPIO interface for resetting the Bluetooth
> device.
>
> Convert it to use the GPIO descriptor interface.
>
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Duje Mihanović <duje.mihanovic@skole.hr>
> ---
>  arch/arm/mach-pxa/gumstix.c | 24 +++++++++++++-----------
>  1 file changed, 13 insertions(+), 11 deletions(-)
>
> diff --git a/arch/arm/mach-pxa/gumstix.c b/arch/arm/mach-pxa/gumstix.c
> index c9f0f62187bd..14e1b9274d7a 100644
> --- a/arch/arm/mach-pxa/gumstix.c
> +++ b/arch/arm/mach-pxa/gumstix.c
> @@ -20,8 +20,8 @@
>  #include <linux/delay.h>
>  #include <linux/mtd/mtd.h>
>  #include <linux/mtd/partitions.h>
> +#include <linux/gpio/consumer.h>
>  #include <linux/gpio/machine.h>
> -#include <linux/gpio.h>
>  #include <linux/err.h>
>  #include <linux/clk.h>
>
> @@ -129,6 +129,9 @@ static void gumstix_udc_init(void)
>  #endif
>
>  #ifdef CONFIG_BT
> +GPIO_LOOKUP_SINGLE(gumstix_bt_gpio_table, "pxa2xx-uart.1", "pxa-gpio",
> +               GPIO_GUMSTIX_BTRESET, "BTRST", GPIO_ACTIVE_LOW);
> +
>  /* Normally, the bootloader would have enabled this 32kHz clock but many
>  ** boards still have u-boot 1.1.4 so we check if it has been turned on and
>  ** if not, we turn it on with a warning message. */
> @@ -153,24 +156,23 @@ static void gumstix_setup_bt_clock(void)
>
>  static void __init gumstix_bluetooth_init(void)
>  {
> -       int err;
> +       struct gpio_desc *desc;
> +
> +       gpiod_add_lookup_table(&gumstix_bt_gpio_table);
>
>         gumstix_setup_bt_clock();
>
> -       err = gpio_request(GPIO_GUMSTIX_BTRESET, "BTRST");
> -       if (err) {
> +       desc = gpiod_get(&pxa_device_btuart.dev, "BTRST", GPIOD_OUT_HIGH);
> +       if (IS_ERR(desc)) {
>                 pr_err("gumstix: failed request gpio for bluetooth reset\n");
>                 return;
>         }
>
> -       err = gpio_direction_output(GPIO_GUMSTIX_BTRESET, 1);
> -       if (err) {
> -               pr_err("gumstix: can't reset bluetooth\n");
> -               return;
> -       }
> -       gpio_set_value(GPIO_GUMSTIX_BTRESET, 0);
> +       gpiod_set_value(desc, 0);
>         udelay(100);
> -       gpio_set_value(GPIO_GUMSTIX_BTRESET, 1);
> +       gpiod_set_value(desc, 1);
> +
> +       gpiod_put(desc);

This changes the way this code works. You release the descriptor here,
it returns to the driver and can be re-requested by someone else. Its
value is also not guaranteed to remain as "active". Is this what you
want?

Bart

>  }
>  #else
>  static void gumstix_bluetooth_init(void)
>
> --
> 2.42.0
>
>

Re: [PATCH RFC v4 5/6] ARM: pxa: Convert gumstix Bluetooth to GPIO descriptors

[Duje Mihanović]

On Monday, October 2, 2023 9:42:52 AM CEST Bartosz Golaszewski wrote:
> This changes the way this code works. You release the descriptor here,
> it returns to the driver and can be re-requested by someone else. Its
> value is also not guaranteed to remain as "active". Is this what you
> want?

Good point. Is it enough to not call gpiod_put() at the end or is it necessary 
to use a static gpio_desc instead of a local one?

Regards,
Duje

Re: [PATCH RFC v4 5/6] ARM: pxa: Convert gumstix Bluetooth to GPIO descriptors

[Bartosz Golaszewski]

On Mon, Oct 2, 2023 at 4:53 PM Duje Mihanović <duje.mihanovic@skole.hr> wrote:
>
> On Monday, October 2, 2023 9:42:52 AM CEST Bartosz Golaszewski wrote:
> > This changes the way this code works. You release the descriptor here,
> > it returns to the driver and can be re-requested by someone else. Its
> > value is also not guaranteed to remain as "active". Is this what you
> > want?
>
> Good point. Is it enough to not call gpiod_put() at the end or is it necessary
> to use a static gpio_desc instead of a local one?
>

Technically it's enough to not put it. It will live on but the
reference will be leaked and most likely this will be reported by
kmemleak. So static desc would make more sense.

Bart

[PATCH RFC v4 6/6] input: ads7846: Move wait_for_sync() logic to driver

[Duje Mihanović]

If this code is left in the board file, the sync GPIO would have to be
separated into another lookup table during conversion to the GPIO
descriptor API (which is also done in this patch).

The only user of this code (Sharp Spitz) is also converted in this
patch.

Signed-off-by: Duje Mihanović <duje.mihanovic@skole.hr>
---
 arch/arm/mach-pxa/spitz.c           | 12 ++----------
 drivers/input/touchscreen/ads7846.c | 22 +++++++++++++++-------
 include/linux/spi/ads7846.h         |  1 -
 3 files changed, 17 insertions(+), 18 deletions(-)

diff --git a/arch/arm/mach-pxa/spitz.c b/arch/arm/mach-pxa/spitz.c
index 701fba130ac4..22d5c5645b8f 100644
--- a/arch/arm/mach-pxa/spitz.c
+++ b/arch/arm/mach-pxa/spitz.c
@@ -520,22 +520,12 @@ static inline void spitz_leds_init(void) {}
  * SSP Devices
  ******************************************************************************/
 #if defined(CONFIG_SPI_PXA2XX) || defined(CONFIG_SPI_PXA2XX_MODULE)
-static void spitz_ads7846_wait_for_hsync(void)
-{
-	while (gpio_get_value(SPITZ_GPIO_HSYNC))
-		cpu_relax();
-
-	while (!gpio_get_value(SPITZ_GPIO_HSYNC))
-		cpu_relax();
-}
-
 static struct ads7846_platform_data spitz_ads7846_info = {
 	.model			= 7846,
 	.vref_delay_usecs	= 100,
 	.x_plate_ohms		= 419,
 	.y_plate_ohms		= 486,
 	.pressure_max		= 1024,
-	.wait_for_sync		= spitz_ads7846_wait_for_hsync,
 };
 
 static struct gpiod_lookup_table spitz_ads7846_gpio_table = {
@@ -543,6 +533,8 @@ static struct gpiod_lookup_table spitz_ads7846_gpio_table = {
 	.table = {
 		GPIO_LOOKUP("gpio-pxa", SPITZ_GPIO_TP_INT,
 			    "pendown", GPIO_ACTIVE_LOW),
+		GPIO_LOOKUP("gpio-pxa", SPITZ_GPIO_HSYNC,
+			    "sync", GPIO_ACTIVE_LOW),
 		{ }
 	},
 };
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index faea40dd66d0..894f179bfa8d 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -138,8 +138,7 @@ struct ads7846 {
 	void			*filter_data;
 	int			(*get_pendown_state)(void);
 	struct gpio_desc	*gpio_pendown;
-
-	void			(*wait_for_sync)(void);
+	struct gpio_desc	*sync;
 };
 
 enum ads7846_filter {
@@ -636,9 +635,14 @@ static const struct attribute_group ads784x_attr_group = {
 };
 
 /*--------------------------------------------------------------------------*/
-
-static void null_wait_for_sync(void)
+static void ads7846_wait_for_sync(struct ads7846 *ts)
 {
+	if (!ts->sync) return;
+	while (!gpiod_get_value(ts->sync))
+		cpu_relax();
+
+	while (gpiod_get_value(ts->sync))
+		cpu_relax();
 }
 
 static int ads7846_debounce_filter(void *ads, int data_idx, int *val)
@@ -803,7 +807,7 @@ static void ads7846_read_state(struct ads7846 *ts)
 	packet->last_cmd_idx = 0;
 
 	while (true) {
-		ts->wait_for_sync();
+		ads7846_wait_for_sync(ts);
 
 		m = &ts->msg[msg_idx];
 		error = spi_sync(ts->spi, m);
@@ -1261,8 +1265,6 @@ static int ads7846_probe(struct spi_device *spi)
 		ts->penirq_recheck_delay_usecs =
 				pdata->penirq_recheck_delay_usecs;
 
-	ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync;
-
 	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
 	snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model);
 
@@ -1361,6 +1363,12 @@ static int ads7846_probe(struct spi_device *spi)
 	if (err)
 		return err;
 
+	ts->sync = devm_gpiod_get_optional(dev, "sync", GPIOD_IN);
+	if (IS_ERR(ts->sync)) {
+		dev_err(dev, "Failed to get sync GPIO: %pe\n", ts->sync);
+		return PTR_ERR(ts->sync);
+	}
+
 	err = input_register_device(input_dev);
 	if (err)
 		return err;
diff --git a/include/linux/spi/ads7846.h b/include/linux/spi/ads7846.h
index a04c1c34c344..fa7c4f119023 100644
--- a/include/linux/spi/ads7846.h
+++ b/include/linux/spi/ads7846.h
@@ -38,7 +38,6 @@ struct ads7846_platform_data {
 	int	gpio_pendown_debounce;	/* platform specific debounce time for
 					 * the gpio_pendown */
 	int	(*get_pendown_state)(void);
-	void	(*wait_for_sync)(void);
 	bool	wakeup;
 	unsigned long irq_flags;
 };

-- 
2.42.0

Re: [PATCH RFC v4 6/6] input: ads7846: Move wait_for_sync() logic to driver

[Andy Shevchenko]

On Sun, Oct 1, 2023 at 5:13 PM Duje Mihanović <duje.mihanovic@skole.hr> wrote:
>
> If this code is left in the board file, the sync GPIO would have to be
> separated into another lookup table during conversion to the GPIO
> descriptor API (which is also done in this patch).
>
> The only user of this code (Sharp Spitz) is also converted in this
> patch.

Suggested-by: Linus... ?

...

> +static void ads7846_wait_for_sync(struct ads7846 *ts)

I would name it ..._wait_for_sync_gpio.

...

> +       ts->sync = devm_gpiod_get_optional(dev, "sync", GPIOD_IN);
> +       if (IS_ERR(ts->sync)) {

> +               dev_err(dev, "Failed to get sync GPIO: %pe\n", ts->sync);
> +               return PTR_ERR(ts->sync);

return dev_err_probe(...); ?

> +       }

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH RFC v4 6/6] input: ads7846: Move wait_for_sync() logic to driver

[Linus Walleij]

On Sun, Oct 1, 2023 at 4:13 PM Duje Mihanović <duje.mihanovic@skole.hr> wrote:

> If this code is left in the board file, the sync GPIO would have to be
> separated into another lookup table during conversion to the GPIO
> descriptor API (which is also done in this patch).
>
> The only user of this code (Sharp Spitz) is also converted in this
> patch.
>
> Signed-off-by: Duje Mihanović <duje.mihanovic@skole.hr>

Looking good!
With Andy's nits fixed:
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

Re: [PATCH RFC v4 6/6] input: ads7846: Move wait_for_sync() logic to driver

[Mark Brown]

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On Sun, Oct 01, 2023 at 04:12:57PM +0200, Duje Mihanović wrote:
> If this code is left in the board file, the sync GPIO would have to be
> separated into another lookup table during conversion to the GPIO
> descriptor API (which is also done in this patch).

Acked-by: Mark Brown <broonie@kernel.org>

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