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.rajamanic...@intel.com>
Signed-off-by: Bin Gao <bin....@intel.com>
Reviewed-by: Andy Shevchenko <andy.shevche...@gmail.com>
Reviewed-by: Mika Westerberg <mika.westerb...@linux.intel.com>
---
Changes in v6:
 - Removed unnecessary wcove_gpio_remove()
 - Used devm_gpiochip_remove() instead of gpiochip_remove()
 - Various coding style changes per Mika's comment
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 | 439 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 453 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..dc586e5
--- /dev/null
+++ b/drivers/gpio/gpio-wcove.c
@@ -0,0 +1,439 @@
+/*
+ * 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)
+{
+       unsigned int reg, mask;
+       int group;
+
+       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);
+       unsigned int val;
+       int ret;
+
+       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 gpio_chip *chip = irq_data_get_irq_chip_data(data);
+       struct wcove_gpio *wg = gpiochip_get_data(chip);
+
+       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 gpio_chip *chip = irq_data_get_irq_chip_data(data);
+       struct wcove_gpio *wg = gpiochip_get_data(chip);
+
+       mutex_lock(&wg->buslock);
+}
+
+static void wcove_bus_sync_unlock(struct irq_data *data)
+{
+       struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+       struct wcove_gpio *wg = gpiochip_get_data(chip);
+       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 gpio_chip *chip = irq_data_get_irq_chip_data(data);
+       struct wcove_gpio *wg = gpiochip_get_data(chip);
+
+       wg->set_irq_mask = false;
+       wg->update |= UPDATE_IRQ_MASK;
+}
+
+static void wcove_irq_mask(struct irq_data *data)
+{
+       struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+       struct wcove_gpio *wg = gpiochip_get_data(chip);
+
+       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)
+{
+       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");
+                       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);
+       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);
+               goto out_remove_gpio;
+       }
+
+       return 0;
+
+out_remove_gpio:
+       devm_gpiochip_remove(dev, &wg->chip);
+       return retval;
+}
+
+static struct platform_driver wcove_gpio_driver = {
+       .driver = {
+               .name = "bxt_wcove_gpio",
+       },
+       .probe = wcove_gpio_probe,
+};
+
+module_platform_driver(wcove_gpio_driver);
+
+MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanic...@intel.com>");
+MODULE_AUTHOR("Bin Gao <bin....@intel.com>");
+MODULE_DESCRIPTION("Intel Whiskey Cove PMIC GPIO Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:bxt_wcove_gpio");
-- 
1.9.1

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