diff options
Diffstat (limited to 'drivers/gpio/gpio-msic.c')
| -rw-r--r-- | drivers/gpio/gpio-msic.c | 314 |
1 files changed, 314 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-msic.c b/drivers/gpio/gpio-msic.c new file mode 100644 index 000000000..7e3c96e4a --- /dev/null +++ b/drivers/gpio/gpio-msic.c @@ -0,0 +1,314 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Intel Medfield MSIC GPIO driver> + * Copyright (c) 2011, Intel Corporation. + * + * Author: Mathias Nyman <mathias.nyman@linux.intel.com> + * Based on intel_pmic_gpio.c + */ + +#include <linux/gpio/driver.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/mfd/intel_msic.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +/* the offset for the mapping of global gpio pin to irq */ +#define MSIC_GPIO_IRQ_OFFSET 0x100 + +#define MSIC_GPIO_DIR_IN 0 +#define MSIC_GPIO_DIR_OUT BIT(5) +#define MSIC_GPIO_TRIG_FALL BIT(1) +#define MSIC_GPIO_TRIG_RISE BIT(2) + +/* masks for msic gpio output GPIOxxxxCTLO registers */ +#define MSIC_GPIO_DIR_MASK BIT(5) +#define MSIC_GPIO_DRV_MASK BIT(4) +#define MSIC_GPIO_REN_MASK BIT(3) +#define MSIC_GPIO_RVAL_MASK (BIT(2) | BIT(1)) +#define MSIC_GPIO_DOUT_MASK BIT(0) + +/* masks for msic gpio input GPIOxxxxCTLI registers */ +#define MSIC_GPIO_GLBYP_MASK BIT(5) +#define MSIC_GPIO_DBNC_MASK (BIT(4) | BIT(3)) +#define MSIC_GPIO_INTCNT_MASK (BIT(2) | BIT(1)) +#define MSIC_GPIO_DIN_MASK BIT(0) + +#define MSIC_NUM_GPIO 24 + +struct msic_gpio { + struct platform_device *pdev; + struct mutex buslock; + struct gpio_chip chip; + int irq; + unsigned irq_base; + unsigned long trig_change_mask; + unsigned trig_type; +}; + +/* + * MSIC has 24 gpios, 16 low voltage (1.2-1.8v) and 8 high voltage (3v). + * Both the high and low voltage gpios are divided in two banks. + * GPIOs are numbered with GPIO0LV0 as gpio_base in the following order: + * GPIO0LV0..GPIO0LV7: low voltage, bank 0, gpio_base + * GPIO1LV0..GPIO1LV7: low voltage, bank 1, gpio_base + 8 + * GPIO0HV0..GPIO0HV3: high voltage, bank 0, gpio_base + 16 + * GPIO1HV0..GPIO1HV3: high voltage, bank 1, gpio_base + 20 + */ + +static int msic_gpio_to_ireg(unsigned offset) +{ + if (offset >= MSIC_NUM_GPIO) + return -EINVAL; + + if (offset < 8) + return INTEL_MSIC_GPIO0LV0CTLI - offset; + if (offset < 16) + return INTEL_MSIC_GPIO1LV0CTLI - offset + 8; + if (offset < 20) + return INTEL_MSIC_GPIO0HV0CTLI - offset + 16; + + return INTEL_MSIC_GPIO1HV0CTLI - offset + 20; +} + +static int msic_gpio_to_oreg(unsigned offset) +{ + if (offset >= MSIC_NUM_GPIO) + return -EINVAL; + + if (offset < 8) + return INTEL_MSIC_GPIO0LV0CTLO - offset; + if (offset < 16) + return INTEL_MSIC_GPIO1LV0CTLO - offset + 8; + if (offset < 20) + return INTEL_MSIC_GPIO0HV0CTLO - offset + 16; + + return INTEL_MSIC_GPIO1HV0CTLO - offset + 20; +} + +static int msic_gpio_direction_input(struct gpio_chip *chip, unsigned offset) +{ + int reg; + + reg = msic_gpio_to_oreg(offset); + if (reg < 0) + return reg; + + return intel_msic_reg_update(reg, MSIC_GPIO_DIR_IN, MSIC_GPIO_DIR_MASK); +} + +static int msic_gpio_direction_output(struct gpio_chip *chip, + unsigned offset, int value) +{ + int reg; + unsigned mask; + + value = (!!value) | MSIC_GPIO_DIR_OUT; + mask = MSIC_GPIO_DIR_MASK | MSIC_GPIO_DOUT_MASK; + + reg = msic_gpio_to_oreg(offset); + if (reg < 0) + return reg; + + return intel_msic_reg_update(reg, value, mask); +} + +static int msic_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + u8 r; + int ret; + int reg; + + reg = msic_gpio_to_ireg(offset); + if (reg < 0) + return reg; + + ret = intel_msic_reg_read(reg, &r); + if (ret < 0) + return ret; + + return !!(r & MSIC_GPIO_DIN_MASK); +} + +static void msic_gpio_set(struct gpio_chip *chip, unsigned offset, int value) +{ + int reg; + + reg = msic_gpio_to_oreg(offset); + if (reg < 0) + return; + + intel_msic_reg_update(reg, !!value , MSIC_GPIO_DOUT_MASK); +} + +/* + * This is called from genirq with mg->buslock locked and + * irq_desc->lock held. We can not access the scu bus here, so we + * store the change and update in the bus_sync_unlock() function below + */ +static int msic_irq_type(struct irq_data *data, unsigned type) +{ + struct msic_gpio *mg = irq_data_get_irq_chip_data(data); + u32 gpio = data->irq - mg->irq_base; + + if (gpio >= mg->chip.ngpio) + return -EINVAL; + + /* mark for which gpio the trigger changed, protected by buslock */ + mg->trig_change_mask |= (1 << gpio); + mg->trig_type = type; + + return 0; +} + +static int msic_gpio_to_irq(struct gpio_chip *chip, unsigned offset) +{ + struct msic_gpio *mg = gpiochip_get_data(chip); + return mg->irq_base + offset; +} + +static void msic_bus_lock(struct irq_data *data) +{ + struct msic_gpio *mg = irq_data_get_irq_chip_data(data); + mutex_lock(&mg->buslock); +} + +static void msic_bus_sync_unlock(struct irq_data *data) +{ + struct msic_gpio *mg = irq_data_get_irq_chip_data(data); + int offset; + int reg; + u8 trig = 0; + + /* We can only get one change at a time as the buslock covers the + entire transaction. The irq_desc->lock is dropped before we are + called but that is fine */ + if (mg->trig_change_mask) { + offset = __ffs(mg->trig_change_mask); + + reg = msic_gpio_to_ireg(offset); + if (reg < 0) + goto out; + + if (mg->trig_type & IRQ_TYPE_EDGE_RISING) + trig |= MSIC_GPIO_TRIG_RISE; + if (mg->trig_type & IRQ_TYPE_EDGE_FALLING) + trig |= MSIC_GPIO_TRIG_FALL; + + intel_msic_reg_update(reg, trig, MSIC_GPIO_INTCNT_MASK); + mg->trig_change_mask = 0; + } +out: + mutex_unlock(&mg->buslock); +} + +/* Firmware does all the masking and unmasking for us, no masking here. */ +static void msic_irq_unmask(struct irq_data *data) { } + +static void msic_irq_mask(struct irq_data *data) { } + +static struct irq_chip msic_irqchip = { + .name = "MSIC-GPIO", + .irq_mask = msic_irq_mask, + .irq_unmask = msic_irq_unmask, + .irq_set_type = msic_irq_type, + .irq_bus_lock = msic_bus_lock, + .irq_bus_sync_unlock = msic_bus_sync_unlock, +}; + +static void msic_gpio_irq_handler(struct irq_desc *desc) +{ + struct irq_data *data = irq_desc_get_irq_data(desc); + struct msic_gpio *mg = irq_data_get_irq_handler_data(data); + struct irq_chip *chip = irq_data_get_irq_chip(data); + struct intel_msic *msic = pdev_to_intel_msic(mg->pdev); + unsigned long pending; + int i; + int bitnr; + u8 pin; + + for (i = 0; i < (mg->chip.ngpio / BITS_PER_BYTE); i++) { + intel_msic_irq_read(msic, INTEL_MSIC_GPIO0LVIRQ + i, &pin); + pending = pin; + + for_each_set_bit(bitnr, &pending, BITS_PER_BYTE) + generic_handle_irq(mg->irq_base + i * BITS_PER_BYTE + bitnr); + } + chip->irq_eoi(data); +} + +static int platform_msic_gpio_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct intel_msic_gpio_pdata *pdata = dev_get_platdata(dev); + struct msic_gpio *mg; + int irq = platform_get_irq(pdev, 0); + int retval; + int i; + + if (irq < 0) { + dev_err(dev, "no IRQ line: %d\n", irq); + return irq; + } + + if (!pdata || !pdata->gpio_base) { + dev_err(dev, "incorrect or missing platform data\n"); + return -EINVAL; + } + + mg = kzalloc(sizeof(*mg), GFP_KERNEL); + if (!mg) + return -ENOMEM; + + dev_set_drvdata(dev, mg); + + mg->pdev = pdev; + mg->irq = irq; + mg->irq_base = pdata->gpio_base + MSIC_GPIO_IRQ_OFFSET; + mg->chip.label = "msic_gpio"; + mg->chip.direction_input = msic_gpio_direction_input; + mg->chip.direction_output = msic_gpio_direction_output; + mg->chip.get = msic_gpio_get; + mg->chip.set = msic_gpio_set; + mg->chip.to_irq = msic_gpio_to_irq; + mg->chip.base = pdata->gpio_base; + mg->chip.ngpio = MSIC_NUM_GPIO; + mg->chip.can_sleep = true; + mg->chip.parent = dev; + + mutex_init(&mg->buslock); + + retval = gpiochip_add_data(&mg->chip, mg); + if (retval) { + dev_err(dev, "Adding MSIC gpio chip failed\n"); + goto err; + } + + for (i = 0; i < mg->chip.ngpio; i++) { + irq_set_chip_data(i + mg->irq_base, mg); + irq_set_chip_and_handler(i + mg->irq_base, + &msic_irqchip, + handle_simple_irq); + } + irq_set_chained_handler_and_data(mg->irq, msic_gpio_irq_handler, mg); + + return 0; +err: + kfree(mg); + return retval; +} + +static struct platform_driver platform_msic_gpio_driver = { + .driver = { + .name = "msic_gpio", + }, + .probe = platform_msic_gpio_probe, +}; + +static int __init platform_msic_gpio_init(void) +{ + return platform_driver_register(&platform_msic_gpio_driver); +} +subsys_initcall(platform_msic_gpio_init); |