Re: [PATCH v4 1/2] mmc: atmel-mci: Convert to gpio descriptors
From: Dmitry Torokhov
Date: Tue Feb 21 2023 - 13:41:41 EST
Hi Balamanikandan,
On Tue, Feb 21, 2023 at 03:12:06PM +0530, Balamanikandan Gunasundar wrote:
> Replace the legacy GPIO APIs with gpio descriptor consumer interface.
> To maintain backward compatibility, we rely on the "cd-inverted"
> property to manage the invertion flag instead of GPIO property.
>
> Signed-off-by: Balamanikandan Gunasundar <balamanikandan.gunasundar@xxxxxxxxxxxxx>
> ---
> drivers/mmc/host/atmel-mci.c | 77 +++++++++++++++++-------------------
> include/linux/atmel-mci.h | 4 +-
> 2 files changed, 39 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
> index dd18440a90c5..ddad5a929634 100644
> --- a/drivers/mmc/host/atmel-mci.c
> +++ b/drivers/mmc/host/atmel-mci.c
> @@ -11,7 +11,6 @@
> #include <linux/dmaengine.h>
> #include <linux/dma-mapping.h>
> #include <linux/err.h>
> -#include <linux/gpio.h>
> #include <linux/init.h>
> #include <linux/interrupt.h>
> #include <linux/io.h>
> @@ -19,7 +18,8 @@
> #include <linux/module.h>
> #include <linux/of.h>
> #include <linux/of_device.h>
> -#include <linux/of_gpio.h>
> +#include <linux/irq.h>
> +#include <linux/gpio/consumer.h>
> #include <linux/platform_device.h>
> #include <linux/scatterlist.h>
> #include <linux/seq_file.h>
> @@ -388,8 +388,8 @@ struct atmel_mci_slot {
> #define ATMCI_CARD_NEED_INIT 1
> #define ATMCI_SHUTDOWN 2
>
> - int detect_pin;
> - int wp_pin;
> + struct gpio_desc *detect_pin;
> + struct gpio_desc *wp_pin;
> bool detect_is_active_high;
>
> struct timer_list detect_timer;
> @@ -637,7 +637,10 @@ atmci_of_init(struct platform_device *pdev)
> pdata->slot[slot_id].bus_width = 1;
>
> pdata->slot[slot_id].detect_pin =
> - of_get_named_gpio(cnp, "cd-gpios", 0);
> + devm_fwnode_gpiod_get(&pdev->dev, of_fwnode_handle(cnp),
> + "cd", GPIOD_IN, "cd-gpios");
> + if (IS_ERR(pdata->slot[slot_id].detect_pin))
> + pdata->slot[slot_id].detect_pin = NULL;
Since we are doing the conversion, may I suggest:
error = PTR_ERR_OR_ZERO(pdata->slot[slot_id].detect_pin);
if (error) {
if (error != -ENOENT)
retrun ERR_PTR(error);
pdata->slot[slot_id].detect_pin = NULL;
}
so that we do not ignore valid errors, and handle deferrals.
I also wonde if it would not be better to move this (acquiring GPIOs)
out of the OF case and into the main probe.
>
> pdata->slot[slot_id].detect_is_active_high =
> of_property_read_bool(cnp, "cd-inverted");
I believe it would be better to have this quirk be handled in
gpiolib-of.c where you would set up polarity of gpiod properly, and then
in this driver you would not need to bother with using raw API and
handle polarity yourself.
> @@ -646,7 +649,10 @@ atmci_of_init(struct platform_device *pdev)
> of_property_read_bool(cnp, "non-removable");
>
> pdata->slot[slot_id].wp_pin =
> - of_get_named_gpio(cnp, "wp-gpios", 0);
> + devm_fwnode_gpiod_get(&pdev->dev, of_fwnode_handle(cnp),
> + "wp", GPIOD_IN, "wp-gpios");
> + if (IS_ERR(pdata->slot[slot_id].wp_pin))
> + pdata->slot[slot_id].wp_pin = NULL;
> }
>
> return pdata;
> @@ -1509,8 +1515,8 @@ static int atmci_get_ro(struct mmc_host *mmc)
> int read_only = -ENOSYS;
> struct atmel_mci_slot *slot = mmc_priv(mmc);
>
> - if (gpio_is_valid(slot->wp_pin)) {
> - read_only = gpio_get_value(slot->wp_pin);
> + if (slot->wp_pin) {
> + read_only = gpiod_get_value(slot->wp_pin);
> dev_dbg(&mmc->class_dev, "card is %s\n",
> read_only ? "read-only" : "read-write");
> }
> @@ -1523,8 +1529,8 @@ static int atmci_get_cd(struct mmc_host *mmc)
> int present = -ENOSYS;
> struct atmel_mci_slot *slot = mmc_priv(mmc);
>
> - if (gpio_is_valid(slot->detect_pin)) {
> - present = !(gpio_get_value(slot->detect_pin) ^
> + if (slot->detect_pin) {
> + present = !(gpiod_get_raw_value(slot->detect_pin) ^
> slot->detect_is_active_high);
> dev_dbg(&mmc->class_dev, "card is %spresent\n",
> present ? "" : "not ");
> @@ -1637,8 +1643,8 @@ static void atmci_detect_change(struct timer_list *t)
> if (test_bit(ATMCI_SHUTDOWN, &slot->flags))
> return;
>
> - enable_irq(gpio_to_irq(slot->detect_pin));
> - present = !(gpio_get_value(slot->detect_pin) ^
> + enable_irq(gpiod_to_irq(slot->detect_pin));
> + present = !(gpiod_get_raw_value(slot->detect_pin) ^
> slot->detect_is_active_high);
> present_old = test_bit(ATMCI_CARD_PRESENT, &slot->flags);
>
> @@ -2237,9 +2243,9 @@ static int atmci_init_slot(struct atmel_mci *host,
> dev_dbg(&mmc->class_dev,
> "slot[%u]: bus_width=%u, detect_pin=%d, "
> "detect_is_active_high=%s, wp_pin=%d\n",
> - id, slot_data->bus_width, slot_data->detect_pin,
> + id, slot_data->bus_width, desc_to_gpio(slot_data->detect_pin),
> slot_data->detect_is_active_high ? "true" : "false",
> - slot_data->wp_pin);
> + desc_to_gpio(slot_data->wp_pin));
>
> mmc->ops = &atmci_ops;
> mmc->f_min = DIV_ROUND_UP(host->bus_hz, 512);
> @@ -2275,31 +2281,24 @@ static int atmci_init_slot(struct atmel_mci *host,
>
> /* Assume card is present initially */
> set_bit(ATMCI_CARD_PRESENT, &slot->flags);
> - if (gpio_is_valid(slot->detect_pin)) {
> - if (devm_gpio_request(&host->pdev->dev, slot->detect_pin,
> - "mmc_detect")) {
> - dev_dbg(&mmc->class_dev, "no detect pin available\n");
> - slot->detect_pin = -EBUSY;
> - } else if (gpio_get_value(slot->detect_pin) ^
> - slot->detect_is_active_high) {
> + if (slot->detect_pin) {
> + if (gpiod_get_raw_value(slot->detect_pin) ^
> + slot->detect_is_active_high) {
> clear_bit(ATMCI_CARD_PRESENT, &slot->flags);
> }
> + } else {
> + dev_dbg(&mmc->class_dev, "no detect pin available\n");
> }
>
> - if (!gpio_is_valid(slot->detect_pin)) {
> + if (!slot->detect_pin) {
> if (slot_data->non_removable)
> mmc->caps |= MMC_CAP_NONREMOVABLE;
> else
> mmc->caps |= MMC_CAP_NEEDS_POLL;
> }
>
> - if (gpio_is_valid(slot->wp_pin)) {
> - if (devm_gpio_request(&host->pdev->dev, slot->wp_pin,
> - "mmc_wp")) {
> - dev_dbg(&mmc->class_dev, "no WP pin available\n");
> - slot->wp_pin = -EBUSY;
> - }
> - }
> + if (!slot->wp_pin)
> + dev_dbg(&mmc->class_dev, "no WP pin available\n");
>
> host->slot[id] = slot;
> mmc_regulator_get_supply(mmc);
> @@ -2309,18 +2308,18 @@ static int atmci_init_slot(struct atmel_mci *host,
> return ret;
> }
>
> - if (gpio_is_valid(slot->detect_pin)) {
> + if (slot->detect_pin) {
> timer_setup(&slot->detect_timer, atmci_detect_change, 0);
>
> - ret = request_irq(gpio_to_irq(slot->detect_pin),
> - atmci_detect_interrupt,
> - IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
> - "mmc-detect", slot);
> + ret = request_irq(gpiod_to_irq(slot->detect_pin),
> + atmci_detect_interrupt,
> + IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
> + "mmc-detect", slot);
> if (ret) {
> dev_dbg(&mmc->class_dev,
> "could not request IRQ %d for detect pin\n",
> - gpio_to_irq(slot->detect_pin));
> - slot->detect_pin = -EBUSY;
> + gpiod_to_irq(slot->detect_pin));
> + slot->detect_pin = NULL;
> }
> }
>
> @@ -2339,10 +2338,8 @@ static void atmci_cleanup_slot(struct atmel_mci_slot *slot,
>
> mmc_remove_host(slot->mmc);
>
> - if (gpio_is_valid(slot->detect_pin)) {
> - int pin = slot->detect_pin;
> -
> - free_irq(gpio_to_irq(pin), slot);
> + if (slot->detect_pin) {
> + free_irq(gpiod_to_irq(slot->detect_pin), slot);
> del_timer_sync(&slot->detect_timer);
> }
>
> diff --git a/include/linux/atmel-mci.h b/include/linux/atmel-mci.h
> index 1491af38cc6e..017e7d8f6126 100644
> --- a/include/linux/atmel-mci.h
> +++ b/include/linux/atmel-mci.h
> @@ -26,8 +26,8 @@
> */
> struct mci_slot_pdata {
> unsigned int bus_width;
> - int detect_pin;
> - int wp_pin;
> + struct gpio_desc *detect_pin;
> + struct gpio_desc *wp_pin;
> bool detect_is_active_high;
> bool non_removable;
> };
> --
> 2.25.1
>
Additionally, I think you can remove handling of the static platform
data as I do not believe anyone is using it in the mainline, as well as
switch to generic device properties instead of using of_*() APIs.
Thanks.
--
Dmitry