On Tue, Jun 6, 2017 at 1:55 PM, Rajmohan Mani [off-list ref] wrote:

This patch adds support for TPS68470 GPIOs.
There are 7 GPIOs and a few sensor related GPIOs.
These GPIOs can be requested and configured as
appropriate.

Signed-off-by: Rajmohan Mani <redacted>

Same comments as Andy already sent, plus:

+static inline struct tps68470_gpio_data *to_gpio_data(struct gpio_chip *gpiochp)
+{
+       return container_of(gpiochp, struct tps68470_gpio_data, gc);
+}

Please use the data pointe inside gpio_chip.

struct tps68470_gpio_data *foo = gpiochip_get_data(gc);

+       ret = tps68470_reg_read(tps, reg, &val);

(...)

+       tps68470_update_bits(tps, reg, BIT(offset), value ? BIT(offset) : 0);

(...)

+       return tps68470_update_bits(tps, TPS68470_GPIO_CTL_REG_A(offset),
+                                TPS68470_GPIO_MODE_MASK,
+                                TPS68470_GPIO_MODE_OUT_CMOS);

(...)

+       return tps68470_update_bits(tps, TPS68470_GPIO_CTL_REG_A(offset),
+                                  TPS68470_GPIO_MODE_MASK, 0x00);

This looks like a reimplementation of regmap. Is it not possible
to create a regmap in the MFD driver and pass that around instead?

+struct gpiod_lookup_table gpios_table = {
+       .dev_id = NULL,
+       .table = {
+                 GPIO_LOOKUP("tps68470-gpio", 0, "gpio.0", GPIO_ACTIVE_HIGH),
+                 GPIO_LOOKUP("tps68470-gpio", 1, "gpio.1", GPIO_ACTIVE_HIGH),
+                 GPIO_LOOKUP("tps68470-gpio", 2, "gpio.2", GPIO_ACTIVE_HIGH),
+                 GPIO_LOOKUP("tps68470-gpio", 3, "gpio.3", GPIO_ACTIVE_HIGH),
+                 GPIO_LOOKUP("tps68470-gpio", 4, "gpio.4", GPIO_ACTIVE_HIGH),
+                 GPIO_LOOKUP("tps68470-gpio", 5, "gpio.5", GPIO_ACTIVE_HIGH),
+                 GPIO_LOOKUP("tps68470-gpio", 6, "gpio.6", GPIO_ACTIVE_HIGH),
+                 GPIO_LOOKUP("tps68470-gpio", 7, "s_enable", GPIO_ACTIVE_HIGH),
+                 GPIO_LOOKUP("tps68470-gpio", 8, "s_idle", GPIO_ACTIVE_HIGH),
+                 GPIO_LOOKUP("tps68470-gpio", 9, "s_resetn", GPIO_ACTIVE_HIGH),
+                 {},
+       },
+};

Hm that's why you include <linux/gpio/machine.h> I guess.

This warrants a big comment above it explaining why this is done like
that and what the use is inside any system with this chip mounted.

+       tps68470_gpio->gc.label = "tps68470-gpio";
+       tps68470_gpio->gc.owner = THIS_MODULE;
+       tps68470_gpio->gc.direction_input = tps68470_gpio_input;
+       tps68470_gpio->gc.direction_output = tps68470_gpio_output;

Please implement .get_direction()

+       tps68470_gpio->gc.get = tps68470_gpio_get;
+       tps68470_gpio->gc.set = tps68470_gpio_set;
+       tps68470_gpio->gc.can_sleep = true;
+       tps68470_gpio->gc.ngpio = TPS68470_N_GPIO;
+       tps68470_gpio->gc.base = -1;
+       tps68470_gpio->gc.parent = &pdev->dev;

Consider assigning the .names() array some sensible line names.

+static int tps68470_gpio_remove(struct platform_device *pdev)
+{
+       struct tps68470_gpio_data *tps68470_gpio = platform_get_drvdata(pdev);
+
+       gpiod_remove_lookup_table(&gpios_table);
+       gpiochip_remove(&tps68470_gpio->gc);

You can't use devm_gpiochip_add()?

Yours,
Linus Walleij