Re: [PATCH 2/6] Input: ams_delta_serio: use GPIO lookup table

Dmitry Torokhov
2018-05-20T20:17:18Z

Hi Janusz,

On Fri, May 18, 2018 at 11:09:50PM +0200, Janusz Krzysztofik wrote:
> Now as the Amstrad Delta board provides GPIO lookup tables, switch from
> GPIO numbers to GPIO descriptors and use the table to locate required
> GPIO pins.
>
> Declare static variables for storing GPIO descriptors and replace
> gpio_ functions with their gpiod_ equivalents.
>
> Pin naming used by the driver should be followed while respective GPIO
> lookup table is initialized by a board init code.
>
> Created and tested against linux-4.17-rc3, on top of patch 1/6 "ARM:
> OMAP1: ams-delta: add GPIO lookup tables"
>
> Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
> ---
> drivers/input/serio/ams_delta_serio.c | 98 +++++++++++++++++++----------------
> 1 file changed, 53 insertions(+), 45 deletions(-)
>
> diff --git a/drivers/input/serio/ams_delta_serio.c b/drivers/input/serio/ams_delta_serio.c
> index 3df501c3421b..dd1f8f118c08 100644
> --- a/drivers/input/serio/ams_delta_serio.c
> +++ b/drivers/input/serio/ams_delta_serio.c
> @@ -20,14 +20,13 @@
> * However, when used with the E3 mailboard that producecs non-standard
> * scancodes, a custom key table must be prepared and loaded from userspace.
> */
> -#include <linux/gpio.h>
> +#include <linux/gpio/consumer.h>
> #include <linux/irq.h>
> #include <linux/serio.h>
> #include <linux/slab.h>
> #include <linux/module.h>
>
> #include <asm/mach-types.h>
> -#include <mach/board-ams-delta.h>
>
> #include <mach/ams-delta-fiq.h>
>
> @@ -36,6 +35,10 @@ MODULE_DESCRIPTION("AMS Delta (E3) keyboard port driver");
> MODULE_LICENSE("GPL");
>
> static struct serio *ams_delta_serio;
> +static struct gpio_desc *gpiod_data;
> +static struct gpio_desc *gpiod_clock;
> +static struct gpio_desc *gpiod_power;
> +static struct gpio_desc *gpiod_dataout;

Since you are doing the conversion: it does not appear that all these
are necessarily GPIOs; for example should not power be gpio-regulator
and data be simply expressed as IRQ resource? And the driver to be
converted into a platform driver?

I think this needs to be done first, because otherwise you are
committing to a certain binding and will have hard time changing it
later.

Thanks.

>
> static int check_data(int data)
> {
> @@ -92,7 +95,7 @@ static irqreturn_t ams_delta_serio_interrupt(int irq, void *dev_id)
> static int ams_delta_serio_open(struct serio *serio)
> {
> /* enable keyboard */
> - gpio_set_value(AMS_DELTA_GPIO_PIN_KEYBRD_PWR, 1);
> + gpiod_set_value(gpiod_power, 1);
>
> return 0;
> }
> @@ -100,32 +103,9 @@ static int ams_delta_serio_open(struct serio *serio)
> static void ams_delta_serio_close(struct serio *serio)
> {
> /* disable keyboard */
> - gpio_set_value(AMS_DELTA_GPIO_PIN_KEYBRD_PWR, 0);
> + gpiod_set_value(gpiod_power, 0);
> }
>
> -static const struct gpio ams_delta_gpios[] __initconst_or_module = {
> - {
> - .gpio = AMS_DELTA_GPIO_PIN_KEYBRD_DATA,
> - .flags = GPIOF_DIR_IN,
> - .label = "serio-data",
> - },
> - {
> - .gpio = AMS_DELTA_GPIO_PIN_KEYBRD_CLK,
> - .flags = GPIOF_DIR_IN,
> - .label = "serio-clock",
> - },
> - {
> - .gpio = AMS_DELTA_GPIO_PIN_KEYBRD_PWR,
> - .flags = GPIOF_OUT_INIT_LOW,
> - .label = "serio-power",
> - },
> - {
> - .gpio = AMS_DELTA_GPIO_PIN_KEYBRD_DATAOUT,
> - .flags = GPIOF_OUT_INIT_LOW,
> - .label = "serio-dataout",
> - },
> -};
> -
> static int __init ams_delta_serio_init(void)
> {
> int err;
> @@ -145,36 +125,62 @@ static int __init ams_delta_serio_init(void)
> strlcpy(ams_delta_serio->phys, "GPIO/serio0",
> sizeof(ams_delta_serio->phys));
>
> - err = gpio_request_array(ams_delta_gpios,
> - ARRAY_SIZE(ams_delta_gpios));
> - if (err) {
> - pr_err("ams_delta_serio: Couldn't request gpio pins\n");
> + gpiod_data = gpiod_get(NULL, "data", GPIOD_IN);
> + if (IS_ERR(gpiod_data)) {
> + err = PTR_ERR(gpiod_data);
> + pr_err("%s: 'data' GPIO request failed (%d)\n", __func__,
> + err);
> goto serio;
> }
> + gpiod_clock = gpiod_get(NULL, "clock", GPIOD_IN);
> + if (IS_ERR(gpiod_clock)) {
> + err = PTR_ERR(gpiod_clock);
> + pr_err("%s: 'clock' GPIO request failed (%d)\n", __func__,
> + err);
> + goto gpio_data;
> + }
> + gpiod_power = gpiod_get(NULL, "power", GPIOD_OUT_LOW);
> + if (IS_ERR(gpiod_power)) {
> + err = PTR_ERR(gpiod_power);
> + pr_err("%s: 'power' GPIO request failed (%d)\n", __func__,
> + err);
> + goto gpio_clock;
> + }
> + gpiod_dataout = gpiod_get(NULL, "dataout", GPIOD_OUT_LOW);
> + if (IS_ERR(gpiod_dataout)) {
> + err = PTR_ERR(gpiod_dataout);
> + pr_err("%s: 'dataout' GPIO request failed (%d)\n",
> + __func__, err);
> + goto gpio_power;
> + }
>
> - err = request_irq(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK),
> - ams_delta_serio_interrupt, IRQ_TYPE_EDGE_RISING,
> - "ams-delta-serio", 0);
> + err = request_irq(gpiod_to_irq(gpiod_clock),
> + ams_delta_serio_interrupt, IRQ_TYPE_EDGE_RISING,
> + "ams-delta-serio", 0);
> if (err < 0) {
> - pr_err("ams_delta_serio: couldn't request gpio interrupt %d\n",
> - gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK));
> - goto gpio;
> + pr_err("%s: 'clock' GPIO interrupt request failed (%d)\n",
> + __func__, err);
> + goto gpio_dataout;
> }
> /*
> * Since GPIO register handling for keyboard clock pin is performed
> * at FIQ level, switch back from edge to simple interrupt handler
> * to avoid bad interaction.
> */
> - irq_set_handler(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK),
> - handle_simple_irq);
> + irq_set_handler(gpiod_to_irq(gpiod_clock), handle_simple_irq);
>
> serio_register_port(ams_delta_serio);
> dev_info(&ams_delta_serio->dev, "%s\n", ams_delta_serio->name);
>
> return 0;
> -gpio:
> - gpio_free_array(ams_delta_gpios,
> - ARRAY_SIZE(ams_delta_gpios));
> +gpio_dataout:
> + gpiod_put(gpiod_dataout);
> +gpio_power:
> + gpiod_put(gpiod_power);
> +gpio_clock:
> + gpiod_put(gpiod_clock);
> +gpio_data:
> + gpiod_put(gpiod_data);
> serio:
> kfree(ams_delta_serio);
> return err;
> @@ -184,8 +190,10 @@ module_init(ams_delta_serio_init);
> static void __exit ams_delta_serio_exit(void)
> {
> serio_unregister_port(ams_delta_serio);
> - free_irq(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK), 0);
> - gpio_free_array(ams_delta_gpios,
> - ARRAY_SIZE(ams_delta_gpios));
> + free_irq(gpiod_to_irq(gpiod_clock), 0);
> + gpiod_put(gpiod_dataout);
> + gpiod_put(gpiod_power);
> + gpiod_put(gpiod_clock);
> + gpiod_put(gpiod_data);
> }
> module_exit(ams_delta_serio_exit);
> --
> 2.16.1
>

--
Dmitry