Re: [PATCH v2] regulator:s5m8767: Fully convert to GPIO descriptors

From: Song Chen
Date: Thu Dec 12 2024 - 00:55:56 EST




在 2024/12/11 21:51, Bartosz Golaszewski 写道:
On Wed, Dec 11, 2024 at 6:10 AM Song Chen <chensong_2000@xxxxxx> wrote:

This converts s5m8767 regulator driver to use GPIO descriptors.

---
v1 - v2:
1, reedit commit message.
2, remove development code.
3, print error msg in dev_err_probe.
4, doesn't set gpiod directions until successfully requesting
all gpiods. It's pretty much equivalent with original code.

Signed-off-by: Song Chen <chensong_2000@xxxxxx>
---
drivers/regulator/s5m8767.c | 106 ++++++++++++++-----------------
include/linux/mfd/samsung/core.h | 4 +-
2 files changed, 48 insertions(+), 62 deletions(-)

diff --git a/drivers/regulator/s5m8767.c b/drivers/regulator/s5m8767.c
index d25cd81e3f36..b23df037336b 100644
--- a/drivers/regulator/s5m8767.c
+++ b/drivers/regulator/s5m8767.c
@@ -5,7 +5,7 @@

#include <linux/cleanup.h>
#include <linux/err.h>
-#include <linux/of_gpio.h>
+#include <linux/of.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/platform_device.h>
@@ -35,8 +35,8 @@ struct s5m8767_info {
u8 buck2_vol[8];
u8 buck3_vol[8];
u8 buck4_vol[8];
- int buck_gpios[3];
- int buck_ds[3];
+ struct gpio_desc *buck_gpios[3];
+ struct gpio_desc *buck_ds[3];
int buck_gpioindex;
};

@@ -272,9 +272,9 @@ static inline int s5m8767_set_high(struct s5m8767_info *s5m8767)
{
int temp_index = s5m8767->buck_gpioindex;

- gpio_set_value(s5m8767->buck_gpios[0], (temp_index >> 2) & 0x1);
- gpio_set_value(s5m8767->buck_gpios[1], (temp_index >> 1) & 0x1);
- gpio_set_value(s5m8767->buck_gpios[2], temp_index & 0x1);
+ gpiod_set_value(s5m8767->buck_gpios[0], (temp_index >> 2) & 0x1);
+ gpiod_set_value(s5m8767->buck_gpios[1], (temp_index >> 1) & 0x1);
+ gpiod_set_value(s5m8767->buck_gpios[2], temp_index & 0x1);


It seems to me that these GPIOs are always manipulated at once. Maybe
consider adding fwnode_gpiod_get_index_array() to GPIO core and using
it here to shrink the code a bit more?

Bart


If I understand you correctly, you mean introducing devm_fwnode_gpiod_get_index_array and in s5m8767_set_high calling gpiod_set_array_value to control s5m8767->buck_gpios.

That is a good point and i can give it a try, but i'm not sure if gpio maintainers like it, they are cautious to introduce new helpers.

Or we can use devm_gpiod_get_array, it's pretty much equivalent effect in s5m8767 even without fwnode specified.

Furthermore, speaking of shrinking code, i'm thinking about using a bitmap to replace buck2_gpiodvs, buck3_gpiodvs and buck4_gpiodvs,

below snippet can be optimized by this bitmap and __builtin_popcount.

if (pdata->buck2_gpiodvs) {
if (pdata->buck3_gpiodvs || pdata->buck4_gpiodvs) {
dev_err(&pdev->dev, "S5M8767 GPIO DVS NOT VALID\n");
return -EINVAL;
}
}

if (pdata->buck3_gpiodvs) {
if (pdata->buck2_gpiodvs || pdata->buck4_gpiodvs) {
dev_err(&pdev->dev, "S5M8767 GPIO DVS NOT VALID\n");
return -EINVAL;
}
}

if (pdata->buck4_gpiodvs) {
if (pdata->buck2_gpiodvs || pdata->buck3_gpiodvs) {
dev_err(&pdev->dev, "S5M8767 GPIO DVS NOT VALID\n");
return -EINVAL;
}
}

what do you think?

Best regards,

Song