Re: [PATCH v6] gpio: add Intel WhiskeyCove PMIC GPIO driver
From: Andy Shevchenko
Date: Mon Jul 25 2016 - 09:31:42 EST
On Tue, Jul 19, 2016 at 9:45 PM, Bin Gao <bin.gao@xxxxxxxxxxxxxxx> wrote:
> This patch introduces a separate GPIO driver for Intel WhiskeyCove PMIC.
> This driver is based on gpio-crystalcove.c.
>
> Signed-off-by: Ajay Thomas <ajay.thomas.david.rajamanickam@xxxxxxxxx>
> Signed-off-by: Bin Gao <bin.gao@xxxxxxxxx>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
There are still (minor) issues, since the patch most likely will not
make v4.8-rc1, my comments below.
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index 536112f..0f33982 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -806,6 +806,19 @@ config GPIO_CRYSTAL_COVE
> This driver can also be built as a module. If so, the module will be
> called gpio-crystalcove.
>
> +config GPIO_WHISKEY_COVE
I think it should follow alphabetical order.
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -34,6 +34,7 @@ obj-$(CONFIG_GPIO_BT8XX) += gpio-bt8xx.o
> obj-$(CONFIG_GPIO_CLPS711X) += gpio-clps711x.o
> obj-$(CONFIG_GPIO_CS5535) += gpio-cs5535.o
> obj-$(CONFIG_GPIO_CRYSTAL_COVE) += gpio-crystalcove.o
> +obj-$(CONFIG_GPIO_WHISKEY_COVE) += gpio-wcove.o
Ditto.
> +++ b/drivers/gpio/gpio-wcove.c
> @@ -0,0 +1,439 @@
> +/*
> + * gpio-wcove.c - Intel Whiskey Cove GPIO Driver
No file name.
> + */
> +
> +#include <linux/seq_file.h>
> +#include <linux/bitops.h>
> +#include <linux/regmap.h>
> +#include <linux/interrupt.h>
> +#include <linux/platform_device.h>
> +#include <linux/gpio/driver.h>
> +#include <linux/mfd/intel_soc_pmic.h>
Perhaps alphabetical order.
> +/* GPIO output control registers(one per pin): 0x4e44 - 0x4e50 */
Space before (.
> +#define GPIO_OUT_CTRL_BASE 0x4e44
> +/* GPIO input control registers(one per pin): 0x4e51 - 0x4e5d */
Ditto.
Needs to be changed in a whole file.
> +#define CTLI_INTCNT_DIS (0)
It seems I commented this.
Please, use
(0 << 1)
> +#define CTLI_INTCNT_NE (1 << 1)
> +#define CTLI_INTCNT_PE (2 << 1)
> +#define CTLI_INTCNT_BE (3 << 1)
> +
> +#define CTLO_DIR_IN (0)
(0 << 5)
> +#define CTLO_DIR_OUT (1 << 5)
> +
> +#define CTLO_DRV_MASK (1 << 4)
I'm not sure it makes sense for 1 bit, perhaps you may use _SHIFT macro instead.
> +#define CTLO_DRV_OD (0)
(0 << 4)
> +#define CTLO_DRV_CMOS CTLO_DRV_MASK
Perhaps
(1 << 4)
> +
> +#define CTLO_DRV_REN (1 << 3)
> +
> +#define CTLO_RVAL_2KDW (0)
(0 << 1)
> +#define CTLO_RVAL_2KUP (1 << 1)
> +#define CTLO_RVAL_50KDW (2 << 1)
Usually DN is used as opposite abbreviation to UP, until else is
mentioned in datasheet.
> +#define CTLO_RVAL_50KUP (3 << 1)
> +
> +#define CTLO_INPUT_SET (CTLO_DRV_CMOS | CTLO_DRV_REN | CTLO_RVAL_2KUP)
> +#define CTLO_OUTPUT_SET (CTLO_DIR_OUT | CTLO_INPUT_SET)
> +
> +enum ctrl_register {
> + CTRL_IN,
> + CTRL_OUT,
> +};
> +
> +/*
> + * struct wcove_gpio - Whiskey Cove GPIO controller
> + * @buslock: for bus lock/sync and unlock.
> + * @chip: the abstract gpio_chip structure.
> + * @regmap: the regmap from the parent device.
> + * @regmap_irq_chip: the regmap of the gpio irq chip.
> + * @update: pending IRQ setting update, to be written to the chip upon unlock.
> + * @intcnt_value: the Interrupt Detect value to be written.
> + * @set_irq_mask: true if the IRQ mask needs to be set, false to clear.
> + */
> +struct wcove_gpio {
> + struct mutex buslock; /* irq_bus_lock */
Useless comment, use above kernel doc lines.
> + struct gpio_chip chip;
> + struct regmap *regmaop;
> + struct regmap_irq_chip_data *regmap_irq_chip;
> + int update;
> + int intcnt_value;
Does value suffix has a value?
> + bool set_irq_mask;
> +};
> +
> +static inline unsigned int to_reg(int gpio, enum ctrl_register reg_type)
> +{
> + unsigned int reg;
> + int bank;
> +
> + if (gpio < BANK0_NR_PINS)
> + bank = 0;
> + else if (gpio < (BANK0_NR_PINS + BANK1_NR_PINS))
Internal parens are redundant.
> + bank = 1;
> + else
> + bank = 2;
> +
> + if (reg_type == CTRL_IN)
> + reg = GPIO_IN_CTRL_BASE + bank;
> + else
> + reg = GPIO_OUT_CTRL_BASE + bank;
> +
> + return reg;
> +}
> +
> +static void wcove_update_irq_mask(struct wcove_gpio *wg, int gpio)
> +{
> + unsigned int reg, mask;
> + int group;
> +
> + group = gpio < GROUP0_NR_IRQS ? 0 : 1;
Entire line is useless.
> + reg = IRQ_MASK_BASE + group;
> + mask = (group == 0) ? BIT(gpio % GROUP0_NR_IRQS) :
> + BIT((gpio - GROUP0_NR_IRQS) % GROUP1_NR_IRQS);
#define IRQ_MASK_BASE(x) (... + (x))
#define IRQ_MASK_BASE0 ...
#define IRQ_MASK_BASE1 ...
if (gpio < ...) {
reg = IRQ_MASK_BASE0;
mask = BIT(...);
} else {
reg = IRQ_MASK_BASE1;
mask = BIT(...);
}
Above will be more readable.
> +
> + if (wg->set_irq_mask)
> + regmap_update_bits(wg->regmap, reg, mask, mask);
> + else
> + regmap_update_bits(wg->regmap, reg, mask, 0);
> +}
> +static irqreturn_t wcove_gpio_irq_handler(int irq, void *data)
> +{
> + unsigned int pending, virq, gpio, mask, offset;
> + struct wcove_gpio *wg = data;
> + u8 p[2];
> +
> + if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
> + pr_err("Failed to read irq status register\n");
dev_err() ?
> + return IRQ_NONE;
> + }
> +
> + pending = p[0] | (p[1] << 8);
> + if (!pending)
> + return IRQ_NONE;
> +
> + /* Iterate until no interrupt is pending */
> + while (pending) {
> + /* One iteration is for all pending bits */
> + for (gpio = 0; gpio < GROUP0_NR_IRQS; gpio++) {
> + if (!(pending & BIT(gpio)))
> + continue;
for_each_bit() ?
> + offset = (gpio > GROUP0_NR_IRQS) ? 1 : 0;
> + mask = (offset == 1) ? BIT(gpio - GROUP0_NR_IRQS) :
> + BIT(gpio);
> + virq = irq_find_mapping(wg->chip.irqdomain, gpio);
> + handle_nested_irq(virq);
> + regmap_update_bits(wg->regmap, IRQ_STATUS_BASE + offset,
> + mask, mask);
> + }
> + /* Next iteration */
> + if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
> + pr_err("Failed to read irq status register\n");
Ditto.
> + break;
> + }
> + pending = p[0] | (p[1] << 8);
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +static void wcove_gpio_dbg_show(struct seq_file *s,
> + struct gpio_chip *chip)
> +{
> + unsigned int ctlo, ctli, irq_mask, irq_status;
> + struct wcove_gpio *wg = gpiochip_get_data(chip);
> + int gpio, offset, group, ret = 0;
> +
> + for (gpio = 0; gpio < WCOVE_GPIO_NUM; gpio++) {
> + group = gpio < GROUP0_NR_IRQS ? 0 : 1;
> + ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_OUT), &ctlo);
> + ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_IN), &ctli);
> + ret += regmap_read(wg->regmap, IRQ_MASK_BASE + group,
> + &irq_mask);
> + ret += regmap_read(wg->regmap, IRQ_STATUS_BASE + group,
> + &irq_status);
> + if (ret) {
> + pr_err("Failed to read registers: ctrl out/in or irq status/mask\n");
dev_err() ?
> + break;
> + }
> +
> + offset = gpio % 8;
> + seq_printf(s, " gpio-%-2d %s %s %s %s ctlo=%2x,%s %s\n",
> + gpio, ctlo & CTLO_DIR_OUT ? "out" : "in ",
> + ctli & 0x1 ? "hi" : "lo",
> + ctli & CTLI_INTCNT_NE ? "fall" : " ",
> + ctli & CTLI_INTCNT_PE ? "rise" : " ",
> + ctlo,
> + irq_mask & BIT(offset) ? "mask " : "unmask",
> + irq_status & BIT(offset) ? "pending" : " ");
> + }
> +}
> +
> +static int wcove_gpio_probe(struct platform_device *pdev)
> +{
> + struct intel_soc_pmic *pmic;
> + struct wcove_gpio *wg;
> + int virq, retval, irq;
> + struct device *dev;
> +
> + pmic = dev_get_drvdata(pdev->dev.parent);
I think this line needs a comment to answer to the question "why parent?"
> + if (!pmic)
> + return -ENODEV;
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0)
> + return irq;
> +
> + dev = &pdev->dev;
> +
> + wg = devm_kzalloc(dev, sizeof(*wg), GFP_KERNEL);
> + if (!wg)
> + return -ENOMEM;
> +
> + wg->regmap_irq_chip = pmic->irq_chip_data_level2;
> +
> + platform_set_drvdata(pdev, wg);
> +
> + mutex_init(&wg->buslock);
> + wg->chip.label = KBUILD_MODNAME;
> + wg->chip.direction_input = wcove_gpio_dir_in;
> + wg->chip.direction_output = wcove_gpio_dir_out;
> + wg->chip.get = wcove_gpio_get;
> + wg->chip.set = wcove_gpio_set;
> + wg->chip.set_single_ended = wcove_gpio_set_single_ended,
> + wg->chip.base = -1;
> + wg->chip.ngpio = WCOVE_VGPIO_NUM;
> + wg->chip.can_sleep = true;
> + wg->chip.parent = pdev->dev.parent;
> + wg->chip.dbg_show = wcove_gpio_dbg_show;
> + wg->regmap = pmic->regmap;
> +
> + retval = devm_gpiochip_add_data(dev, &wg->chip, wg);
> + if (retval) {
> + dev_warn(dev, "add gpio chip error: %d\n", retval);
> + return retval;
> + }
> +
> + gpiochip_irqchip_add(&wg->chip, &wcove_irqchip, 0,
> + handle_simple_irq, IRQ_TYPE_NONE);
> +
> + virq = regmap_irq_get_virq(wg->regmap_irq_chip, irq);
> + if (virq < 0) {
> + dev_err(dev, "failed to get virtual irq by irq %d\n", irq);
> + retval = virq;
> + goto out_remove_gpio;
> + }
> +
> + retval = devm_request_threaded_irq(dev, virq, NULL,
> + wcove_gpio_irq_handler, IRQF_ONESHOT, pdev->name, wg);
> +
> + if (retval) {
> + dev_warn(dev, "request irq(%d) failed: %d\n", retval, virq);
It's not a warning as I can see.
Also question if it's useful at all to print anything here?
> + goto out_remove_gpio;
> + }
> +
> + return 0;
> +
> +out_remove_gpio:
> + devm_gpiochip_remove(dev, &wg->chip);
> + return retval;
Useless lines.
--
With Best Regards,
Andy Shevchenko