[PATCH v5] gpio: add Intel WhiskeyCove GPIO driver
From: Bin Gao
Date: Mon Jul 11 2016 - 20:02:57 EST
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>
---
Changes in v5:
- Revisited the interrupt handler code to iterate until all pending
interrupts are handled. This change is to avoid missing interrupt
when we're inside the interrupt handler.
- Used regmap_bulk_read() to read address adjacent registers.
Changes in v4:
- Converted CTLI_INTCNT_XX macros to less verbose ones INT_DETECT_XX.
- Add comments about why there is no .pm for the driver.
- Header files re-ordered.
- Various coding style change to address Andy's comments.
Changes in v3:
- Fixed the year in copyright line(2015-->2016).
- Removed DRV_NAME macro.
- Added kernel-doc for regmap_irq_chip of the wcove_gpio structure.
- Line length fix.
Changes in v2:
- Typo fix (Whsikey --> Whiskey).
- Included linux/gpio/driver.h instead of linux/gpio.h
- Implemented .set_single_ended().
- Added GPIO register description.
- Replaced container_of() with gpiochip_get_data().
- Removed unnecessary "if (gpio > WCOVE_VGPIO_NUM" check.
- Removed the device id table and added MODULE_ALIAS().
drivers/gpio/Kconfig | 13 ++
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-wcove.c | 444 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 458 insertions(+)
create mode 100644 drivers/gpio/gpio-wcove.c
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
+ 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
+ inside.
+
+ This driver can also be built as a module. If so, the module will be
+ called gpio-wcove.
+
config GPIO_CS5535
tristate "AMD CS5535/CS5536 GPIO support"
depends on MFD_CS5535
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 991598e..fff6914 100644
--- 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-$(CONFIG_GPIO_WHISKEY_COVE) += gpio-wcove.o
obj-$(CONFIG_GPIO_DA9052) += gpio-da9052.o
obj-$(CONFIG_GPIO_DA9055) += gpio-da9055.o
obj-$(CONFIG_GPIO_DAVINCI) += gpio-davinci.o
diff --git a/drivers/gpio/gpio-wcove.c b/drivers/gpio/gpio-wcove.c
new file mode 100644
index 0000000..e29e5a9
--- /dev/null
+++ b/drivers/gpio/gpio-wcove.c
@@ -0,0 +1,444 @@
+/*
+ * gpio-wcove.c - Intel Whiskey Cove GPIO Driver
+ *
+ * This driver is written based on gpio-crystalcove.c
+ *
+ * Copyright (C) 2016 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#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>
+
+/*
+ * 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
+#define UPDATE_IRQ_TYPE BIT(0)
+#define UPDATE_IRQ_MASK BIT(1)
+
+#define CTLI_INTCNT_DIS (0)
+#define CTLI_INTCNT_NE (1 << 1)
+#define CTLI_INTCNT_PE (2 << 1)
+#define CTLI_INTCNT_BE (3 << 1)
+
+#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)
+
+#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;
+
+ 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, mask;
+
+ group = gpio < GROUP0_NR_IRQS ? 0 : 1;
+ reg = IRQ_MASK_BASE + group;
+ mask = (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, mask, mask);
+ else
+ regmap_update_bits(wg->regmap, reg, mask, 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;
+
+ 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);
+}
+
+static void wcove_bus_sync_unlock(struct irq_data *data)
+{
+ struct wcove_gpio *wg = gpiochip_get_data(
+ irq_data_get_irq_chip_data(data));
+ 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,
+};
+
+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");
+ 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;
+ 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");
+ break;
+ }
+ pending = p[0] | (p[1] << 8);
+ }
+
+ 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, ret = 0;
+ unsigned int ctlo, ctli, irq_mask, irq_status;
+
+ 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");
+ 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)
+{
+ 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);
+
+ 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);
+ goto out_remove_gpio;
+ }
+
+ return 0;
+
+out_remove_gpio:
+ gpiochip_remove(&wg->chip);
+ return retval;
+}
+
+static int wcove_gpio_remove(struct platform_device *pdev)
+{
+ struct wcove_gpio *wg = platform_get_drvdata(pdev);
+
+ gpiochip_remove(&wg->chip);
+ return 0;
+}
+
+static struct platform_driver wcove_gpio_driver = {
+ .driver = {
+ .name = "bxt_wcove_gpio",
+ },
+ .probe = wcove_gpio_probe,
+ .remove = wcove_gpio_remove,
+};
+
+module_platform_driver(wcove_gpio_driver);
+
+MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@xxxxxxxxx>");
+MODULE_AUTHOR("Bin Gao <bin.gao@xxxxxxxxx>");
+MODULE_DESCRIPTION("Intel Whiskey Cove GPIO Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:bxt_wcove_gpio");
--
1.9.1