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Date: Tue, 21 Jun 2016 02:19:57 +0300
From: Andy Shevchenko <andy.shevchenko@...il.com>
To: Bin Gao <bin.gao@...ux.intel.com>
Cc: Mika Westerberg <mika.westerberg@...ux.intel.com>,
Mathias Nyman <mathias.nyman@...ux.intel.com>,
Linus Walleij <linus.walleij@...aro.org>,
Alexandre Courbot <gnurou@...il.com>,
"linux-gpio@...r.kernel.org" <linux-gpio@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
Ajay Thomas <ajay.thomas.david.rajamanickam@...el.com>,
Yegnesh S Iyer <yegnesh.s.iyer@...el.com>,
Bin Gao <bin.gao@...el.com>
Subject: Re: [PATCH v3] gpio: add Intel WhiskeyCove GPIO driver
On Mon, Jun 20, 2016 at 9:02 PM, Bin Gao <bin.gao@...ux.intel.com> wrote:
> This patch introduces a separate GPIO driver for Intel WhiskeyCove PMIC.
> This driver is based on gpio-crystalcove.c.
My comments below.
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index cebcb40..ac74299 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
> + tristate "GPIO support for Whiskey Cove PMIC"
> + depends on INTEL_SOC_PMIC
> + select GPIOLIB_IRQCHIP
> + help
> + Support for GPIO pins on Whiskey Cove PMIC.
> +
> + Say Yes if you have a Intel SoC based tablet with Whiskey Cove PMIC
What if I have not a tablet with WC PMIC inside?
> + inside.
> +
> + This driver can also be built as a module. If so, the module will be
> + called gpio-wcove.
> +#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>
Alphabetical order?
> +
> +/*
> + * Whiskey Cove PMIC has 13 physical GPIO pins divided into 3 banks:
> + * Bank 0: Pin 0 - 6
> + * Bank 1: Pin 7 - 10
> + * Bank 2: Pin 11 -12
> + * Each pin has one output control register and one input control register.
> + */
> +#define BANK0_NR_PINS 7
> +#define BANK1_NR_PINS 4
> +#define BANK2_NR_PINS 2
> +#define WCOVE_GPIO_NUM (BANK0_NR_PINS + BANK1_NR_PINS + BANK2_NR_PINS)
> +#define WCOVE_VGPIO_NUM 94
> +/* GPIO output control registers(one per pin): 0x4e44 - 0x4e50 */
> +#define GPIO_OUT_CTRL_BASE 0x4e44
> +/* GPIO input control registers(one per pin): 0x4e51 - 0x4e5d */
> +#define GPIO_IN_CTRL_BASE 0x4e51
> +
> +/*
> + * GPIO interrupts are organized in two groups:
> + * Group 0: Bank 0 pins (Pin 0 - 6)
> + * Group 1: Bank 1 and Bank 2 pins (Pin 7 - 12)
> + * Each group has two registers(one bit per pin): status and mask.
> + */
> +#define GROUP0_NR_IRQS 7
> +#define GROUP1_NR_IRQS 6
> +#define IRQ_MASK_BASE 0x4e19
> +#define IRQ_STATUS_BASE 0x4e0b
Can you define all your bases as a) offsets by value, and b) with
_OFFSET suffix instead of _BASE, though second one is up to you.
> +#define UPDATE_IRQ_TYPE BIT(0)
> +#define UPDATE_IRQ_MASK BIT(1)
> +
> +#define CTLI_INTCNT_DIS (0)
(0 << 1) or...
> +#define CTLI_INTCNT_NE (1 << 1)
> +#define CTLI_INTCNT_PE (2 << 1)
> +#define CTLI_INTCNT_BE (3 << 1)
...INTCNT(x) ((x) << 1)
...DIS 0
...NE 1
and so on.
Same for all similar blocks of constants.
> +
> +#define CTLO_DIR_IN (0)
> +#define CTLO_DIR_OUT (1 << 5)
> +
> +#define CTLO_DRV_MASK (1 << 4)
> +#define CTLO_DRV_OD (0)
> +#define CTLO_DRV_CMOS CTLO_DRV_MASK
> +
> +#define CTLO_DRV_REN (1 << 3)
> +
> +#define CTLO_RVAL_2KDW (0)
> +#define CTLO_RVAL_2KUP (1 << 1)
> +#define CTLO_RVAL_50KDW (2 << 1)
> +#define CTLO_RVAL_50KUP (3 << 1)
Wait, are you sure that's is pure gpio and not a full pinctrl (pinconf) + gpio?
> +
> +#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 */
> + struct gpio_chip chip;
> + struct regmap *regmap;
> + struct regmap_irq_chip_data *regmap_irq_chip;
> + int update;
> + int intcnt_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))
> + bank = 1;
> + else
> + bank = 2;
It might be better to use a constant struct to iterate through:
struct gpio_banks {
... bankno;
... start;
... len;
};
Though I have no strong opinion here since it will have only 3 records.
> +
> + 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)
> +{
> + int group;
> + unsigned int reg, bit;
> +
> + group = gpio < GROUP0_NR_IRQS ? 0 : 1;
> + reg = IRQ_MASK_BASE + group;
> + bit = (group == 0) ? BIT(gpio % GROUP0_NR_IRQS) :
> + BIT((gpio - GROUP0_NR_IRQS) % GROUP1_NR_IRQS);
> +
> + if (wg->set_irq_mask)
> + regmap_update_bits(wg->regmap, reg, bit, 1);
> + else
> + regmap_update_bits(wg->regmap, reg, bit, 0);
> +}
> +
> +static void wcove_update_irq_ctrl(struct wcove_gpio *wg, int gpio)
> +{
> + unsigned int reg = to_reg(gpio, CTRL_IN);
> +
> + regmap_update_bits(wg->regmap, reg, CTLI_INTCNT_BE, wg->intcnt_value);
> +}
> +
> +static int wcove_gpio_dir_in(struct gpio_chip *chip, unsigned int gpio)
> +{
> + struct wcove_gpio *wg = gpiochip_get_data(chip);
> +
> + return regmap_write(wg->regmap, to_reg(gpio, CTRL_OUT),
> + CTLO_INPUT_SET);
> +}
> +
> +static int wcove_gpio_dir_out(struct gpio_chip *chip, unsigned int gpio,
> + int value)
> +{
> + struct wcove_gpio *wg = gpiochip_get_data(chip);
> +
> + return regmap_write(wg->regmap, to_reg(gpio, CTRL_OUT),
> + CTLO_OUTPUT_SET | value);
> +}
> +
> +static int wcove_gpio_get(struct gpio_chip *chip, unsigned int gpio)
> +{
> + struct wcove_gpio *wg = gpiochip_get_data(chip);
> + int ret;
> + unsigned int val;
Reverse xmas tree, please.
> + ret = regmap_read(wg->regmap, to_reg(gpio, CTRL_IN), &val);
> + if (ret)
> + return ret;
> +
> + return val & 0x1;
> +}
> +
> +static void wcove_gpio_set(struct gpio_chip *chip,
> + unsigned int gpio, int value)
> +{
> + struct wcove_gpio *wg = gpiochip_get_data(chip);
> +
> + if (value)
> + regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT), 1, 1);
> + else
> + regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT), 1, 0);
> +}
> +
> +static int wcove_gpio_set_single_ended(struct gpio_chip *chip,
> + unsigned int gpio,
> + enum single_ended_mode mode)
> +{
> + struct wcove_gpio *wg = gpiochip_get_data(chip);
> +
> + switch (mode) {
> + case LINE_MODE_OPEN_DRAIN:
> + return regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT),
> + CTLO_DRV_MASK, CTLO_DRV_OD);
> + case LINE_MODE_PUSH_PULL:
> + return regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT),
> + CTLO_DRV_MASK, CTLO_DRV_CMOS);
> + default:
> + break;
> + }
> +
> + return -ENOTSUPP;
> +}
> +
> +static int wcove_irq_type(struct irq_data *data, unsigned int type)
> +{
> + struct wcove_gpio *wg = gpiochip_get_data(
> + irq_data_get_irq_chip_data(data));
> +
> + switch (type) {
> + case IRQ_TYPE_NONE:
> + wg->intcnt_value = CTLI_INTCNT_DIS;
> + break;
> + case IRQ_TYPE_EDGE_BOTH:
> + wg->intcnt_value = CTLI_INTCNT_BE;
> + break;
> + case IRQ_TYPE_EDGE_RISING:
> + wg->intcnt_value = CTLI_INTCNT_PE;
> + break;
> + case IRQ_TYPE_EDGE_FALLING:
> + wg->intcnt_value = CTLI_INTCNT_NE;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + wg->update |= UPDATE_IRQ_TYPE;
> +
> + return 0;
> +}
> +
> +static void wcove_bus_lock(struct irq_data *data)
> +{
> + struct wcove_gpio *wg = gpiochip_get_data(
> + irq_data_get_irq_chip_data(data));
> +
> + mutex_lock(&wg->buslock);
I suppose you have to add a hint to static analyzer here and below.
> +}
> +
> +static void wcove_bus_sync_unlock(struct irq_data *data)
> +{
> + struct wcove_gpio *wg = gpiochip_get_data(
> + irq_data_get_irq_chip_data(data));
One line
> + int gpio = data->hwirq;
> +
> + if (wg->update & UPDATE_IRQ_TYPE)
> + wcove_update_irq_ctrl(wg, gpio);
> + if (wg->update & UPDATE_IRQ_MASK)
> + wcove_update_irq_mask(wg, gpio);
> + wg->update = 0;
> +
> + mutex_unlock(&wg->buslock);
> +}
> +
> +static void wcove_irq_unmask(struct irq_data *data)
> +{
> + struct wcove_gpio *wg = gpiochip_get_data(
> + irq_data_get_irq_chip_data(data));
> +
> + wg->set_irq_mask = false;
> + wg->update |= UPDATE_IRQ_MASK;
> +}
> +
> +static void wcove_irq_mask(struct irq_data *data)
> +{
> + struct wcove_gpio *wg = gpiochip_get_data(
> + irq_data_get_irq_chip_data(data));
> +
> + wg->set_irq_mask = true;
> + wg->update |= UPDATE_IRQ_MASK;
> +}
> +
> +static struct irq_chip wcove_irqchip = {
> + .name = "Whiskey Cove",
> + .irq_mask = wcove_irq_mask,
> + .irq_unmask = wcove_irq_unmask,
> + .irq_set_type = wcove_irq_type,
> + .irq_bus_lock = wcove_bus_lock,
> + .irq_bus_sync_unlock = wcove_bus_sync_unlock,
Is it my mail client or they are not aligned?
> +};
> +
> +static irqreturn_t wcove_gpio_irq_handler(int irq, void *data)
> +{
> + struct wcove_gpio *wg = data;
> + unsigned int p0, p1, virq;
> + int pending, gpio;
unsigned int gpio;
> +
> + if (regmap_read(wg->regmap, IRQ_STATUS_BASE, &p0) ||
Better to use + 0 here.
> + regmap_read(wg->regmap, IRQ_STATUS_BASE + 1, &p1)) {
> + pr_err("%s(): regmap_read() failed.\n", __func__);
dev_err();
> + return IRQ_NONE;
> + }
> +
> + pending = p0 | (p1 << 8);
> +
> + for (gpio = 0; gpio < WCOVE_GPIO_NUM; gpio++) {
> + if (pending & BIT(gpio)) {
> + virq = irq_find_mapping(wg->chip.irqdomain, gpio);
> + handle_nested_irq(virq);
> + }
> + }
> +
> + regmap_write(wg->regmap, IRQ_STATUS_BASE, p0);
Ditto.
> + regmap_write(wg->regmap, IRQ_STATUS_BASE + 1, p1);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static void wcove_gpio_dbg_show(struct seq_file *s,
> + struct gpio_chip *chip)
> +{
> + struct wcove_gpio *wg = gpiochip_get_data(chip);
> + int gpio, offset, group;
> + unsigned int ctlo, ctli, irq_mask, irq_status;
> +
> + for (gpio = 0; gpio < WCOVE_GPIO_NUM; gpio++) {
> + group = gpio < GROUP0_NR_IRQS ? 0 : 1;
> + regmap_read(wg->regmap, to_reg(gpio, CTRL_OUT), &ctlo);
> + regmap_read(wg->regmap, to_reg(gpio, CTRL_IN), &ctli);
> + regmap_read(wg->regmap, IRQ_MASK_BASE + group, &irq_mask);
> + regmap_read(wg->regmap, IRQ_STATUS_BASE + group, &irq_status);
> +
> + 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)
> +{
> + int virq, retval, irq = platform_get_irq(pdev, 0);
> + struct wcove_gpio *wg;
> + struct device *dev = pdev->dev.parent;
> + struct intel_soc_pmic *pmic = dev_get_drvdata(dev);
> +
Put irq assignment here.
> + if (irq < 0)
> + return irq;
> +
> + wg = devm_kzalloc(&pdev->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 = dev;
> + wg->chip.dbg_show = wcove_gpio_dbg_show;
> + wg->regmap = pmic->regmap;
> +
> + retval = devm_gpiochip_add_data(&pdev->dev, &wg->chip, wg);
> + if (retval) {
> + dev_warn(&pdev->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(&pdev->dev,
> + "failed to get virtual interrupt=%d\n", irq);
> + retval = virq;
> + goto out_remove_gpio;
> + }
> +
> + retval = devm_request_threaded_irq(&pdev->dev, virq,
> + NULL, wcove_gpio_irq_handler,
> + IRQF_ONESHOT, pdev->name, wg);
> +
> + if (retval) {
> + dev_warn(&pdev->dev, "request irq failed: %d, virq: %d\n",
> + retval, virq);
Non fatal? Needs an explanation in the comment.
> + goto out_remove_gpio;
> + }
> +
> + return 0;
> +
> +out_remove_gpio:
> + gpiochip_remove(&wg->chip);
> + return retval;
BLUNDER! You are using devm_*() API.
> +}
> +
> +static int wcove_gpio_remove(struct platform_device *pdev)
> +{
> + struct wcove_gpio *wg = platform_get_drvdata(pdev);
> +
> + gpiochip_remove(&wg->chip);
Ditto.
> + return 0;
> +}
> +
> +static struct platform_driver wcove_gpio_driver = {
> + .driver = {
> + .name = "bxt_wcove_gpio",
No PM?
> + },
> + .probe = wcove_gpio_probe,
> + .remove = wcove_gpio_remove,
> +};
--
With Best Regards,
Andy Shevchenko
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