diff options
Diffstat (limited to 'drivers/gpio/gpio-zynq.c')
| -rw-r--r-- | drivers/gpio/gpio-zynq.c | 727 |
1 files changed, 727 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-zynq.c b/drivers/gpio/gpio-zynq.c new file mode 100644 index 000000000..184c4b1b2 --- /dev/null +++ b/drivers/gpio/gpio-zynq.c @@ -0,0 +1,727 @@ +/* + * Xilinx Zynq GPIO device driver + * + * Copyright (C) 2009 - 2014 Xilinx, Inc. + * + * This program is free software; you can redistribute it and/or modify it under + * the terms of the GNU General Public License as published by the Free Software + * Foundation; either version 2 of the License, or (at your option) any later + * version. + */ + +#include <linux/bitops.h> +#include <linux/clk.h> +#include <linux/gpio/driver.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> + +#define DRIVER_NAME "zynq-gpio" + +/* Maximum banks */ +#define ZYNQ_GPIO_MAX_BANK 4 + +#define ZYNQ_GPIO_BANK0_NGPIO 32 +#define ZYNQ_GPIO_BANK1_NGPIO 22 +#define ZYNQ_GPIO_BANK2_NGPIO 32 +#define ZYNQ_GPIO_BANK3_NGPIO 32 + +#define ZYNQ_GPIO_NR_GPIOS (ZYNQ_GPIO_BANK0_NGPIO + \ + ZYNQ_GPIO_BANK1_NGPIO + \ + ZYNQ_GPIO_BANK2_NGPIO + \ + ZYNQ_GPIO_BANK3_NGPIO) + +#define ZYNQ_GPIO_BANK0_PIN_MIN 0 +#define ZYNQ_GPIO_BANK0_PIN_MAX (ZYNQ_GPIO_BANK0_PIN_MIN + \ + ZYNQ_GPIO_BANK0_NGPIO - 1) +#define ZYNQ_GPIO_BANK1_PIN_MIN (ZYNQ_GPIO_BANK0_PIN_MAX + 1) +#define ZYNQ_GPIO_BANK1_PIN_MAX (ZYNQ_GPIO_BANK1_PIN_MIN + \ + ZYNQ_GPIO_BANK1_NGPIO - 1) +#define ZYNQ_GPIO_BANK2_PIN_MIN (ZYNQ_GPIO_BANK1_PIN_MAX + 1) +#define ZYNQ_GPIO_BANK2_PIN_MAX (ZYNQ_GPIO_BANK2_PIN_MIN + \ + ZYNQ_GPIO_BANK2_NGPIO - 1) +#define ZYNQ_GPIO_BANK3_PIN_MIN (ZYNQ_GPIO_BANK2_PIN_MAX + 1) +#define ZYNQ_GPIO_BANK3_PIN_MAX (ZYNQ_GPIO_BANK3_PIN_MIN + \ + ZYNQ_GPIO_BANK3_NGPIO - 1) + + +/* Register offsets for the GPIO device */ +/* LSW Mask & Data -WO */ +#define ZYNQ_GPIO_DATA_LSW_OFFSET(BANK) (0x000 + (8 * BANK)) +/* MSW Mask & Data -WO */ +#define ZYNQ_GPIO_DATA_MSW_OFFSET(BANK) (0x004 + (8 * BANK)) +/* Data Register-RW */ +#define ZYNQ_GPIO_DATA_RO_OFFSET(BANK) (0x060 + (4 * BANK)) +/* Direction mode reg-RW */ +#define ZYNQ_GPIO_DIRM_OFFSET(BANK) (0x204 + (0x40 * BANK)) +/* Output enable reg-RW */ +#define ZYNQ_GPIO_OUTEN_OFFSET(BANK) (0x208 + (0x40 * BANK)) +/* Interrupt mask reg-RO */ +#define ZYNQ_GPIO_INTMASK_OFFSET(BANK) (0x20C + (0x40 * BANK)) +/* Interrupt enable reg-WO */ +#define ZYNQ_GPIO_INTEN_OFFSET(BANK) (0x210 + (0x40 * BANK)) +/* Interrupt disable reg-WO */ +#define ZYNQ_GPIO_INTDIS_OFFSET(BANK) (0x214 + (0x40 * BANK)) +/* Interrupt status reg-RO */ +#define ZYNQ_GPIO_INTSTS_OFFSET(BANK) (0x218 + (0x40 * BANK)) +/* Interrupt type reg-RW */ +#define ZYNQ_GPIO_INTTYPE_OFFSET(BANK) (0x21C + (0x40 * BANK)) +/* Interrupt polarity reg-RW */ +#define ZYNQ_GPIO_INTPOL_OFFSET(BANK) (0x220 + (0x40 * BANK)) +/* Interrupt on any, reg-RW */ +#define ZYNQ_GPIO_INTANY_OFFSET(BANK) (0x224 + (0x40 * BANK)) + +/* Disable all interrupts mask */ +#define ZYNQ_GPIO_IXR_DISABLE_ALL 0xFFFFFFFF + +/* Mid pin number of a bank */ +#define ZYNQ_GPIO_MID_PIN_NUM 16 + +/* GPIO upper 16 bit mask */ +#define ZYNQ_GPIO_UPPER_MASK 0xFFFF0000 + +/** + * struct zynq_gpio - gpio device private data structure + * @chip: instance of the gpio_chip + * @base_addr: base address of the GPIO device + * @clk: clock resource for this controller + * @irq: interrupt for the GPIO device + */ +struct zynq_gpio { + struct gpio_chip chip; + void __iomem *base_addr; + struct clk *clk; + int irq; +}; + +static struct irq_chip zynq_gpio_level_irqchip; +static struct irq_chip zynq_gpio_edge_irqchip; +/** + * zynq_gpio_get_bank_pin - Get the bank number and pin number within that bank + * for a given pin in the GPIO device + * @pin_num: gpio pin number within the device + * @bank_num: an output parameter used to return the bank number of the gpio + * pin + * @bank_pin_num: an output parameter used to return pin number within a bank + * for the given gpio pin + * + * Returns the bank number and pin offset within the bank. + */ +static inline void zynq_gpio_get_bank_pin(unsigned int pin_num, + unsigned int *bank_num, + unsigned int *bank_pin_num) +{ + switch (pin_num) { + case ZYNQ_GPIO_BANK0_PIN_MIN ... ZYNQ_GPIO_BANK0_PIN_MAX: + *bank_num = 0; + *bank_pin_num = pin_num; + break; + case ZYNQ_GPIO_BANK1_PIN_MIN ... ZYNQ_GPIO_BANK1_PIN_MAX: + *bank_num = 1; + *bank_pin_num = pin_num - ZYNQ_GPIO_BANK1_PIN_MIN; + break; + case ZYNQ_GPIO_BANK2_PIN_MIN ... ZYNQ_GPIO_BANK2_PIN_MAX: + *bank_num = 2; + *bank_pin_num = pin_num - ZYNQ_GPIO_BANK2_PIN_MIN; + break; + case ZYNQ_GPIO_BANK3_PIN_MIN ... ZYNQ_GPIO_BANK3_PIN_MAX: + *bank_num = 3; + *bank_pin_num = pin_num - ZYNQ_GPIO_BANK3_PIN_MIN; + break; + default: + WARN(true, "invalid GPIO pin number: %u", pin_num); + *bank_num = 0; + *bank_pin_num = 0; + break; + } +} + +static const unsigned int zynq_gpio_bank_offset[] = { + ZYNQ_GPIO_BANK0_PIN_MIN, + ZYNQ_GPIO_BANK1_PIN_MIN, + ZYNQ_GPIO_BANK2_PIN_MIN, + ZYNQ_GPIO_BANK3_PIN_MIN, +}; + +/** + * zynq_gpio_get_value - Get the state of the specified pin of GPIO device + * @chip: gpio_chip instance to be worked on + * @pin: gpio pin number within the device + * + * This function reads the state of the specified pin of the GPIO device. + * + * Return: 0 if the pin is low, 1 if pin is high. + */ +static int zynq_gpio_get_value(struct gpio_chip *chip, unsigned int pin) +{ + u32 data; + unsigned int bank_num, bank_pin_num; + struct zynq_gpio *gpio = container_of(chip, struct zynq_gpio, chip); + + zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num); + + data = readl_relaxed(gpio->base_addr + + ZYNQ_GPIO_DATA_RO_OFFSET(bank_num)); + + return (data >> bank_pin_num) & 1; +} + +/** + * zynq_gpio_set_value - Modify the state of the pin with specified value + * @chip: gpio_chip instance to be worked on + * @pin: gpio pin number within the device + * @state: value used to modify the state of the specified pin + * + * This function calculates the register offset (i.e to lower 16 bits or + * upper 16 bits) based on the given pin number and sets the state of a + * gpio pin to the specified value. The state is either 0 or non-zero. + */ +static void zynq_gpio_set_value(struct gpio_chip *chip, unsigned int pin, + int state) +{ + unsigned int reg_offset, bank_num, bank_pin_num; + struct zynq_gpio *gpio = container_of(chip, struct zynq_gpio, chip); + + zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num); + + if (bank_pin_num >= ZYNQ_GPIO_MID_PIN_NUM) { + /* only 16 data bits in bit maskable reg */ + bank_pin_num -= ZYNQ_GPIO_MID_PIN_NUM; + reg_offset = ZYNQ_GPIO_DATA_MSW_OFFSET(bank_num); + } else { + reg_offset = ZYNQ_GPIO_DATA_LSW_OFFSET(bank_num); + } + + /* + * get the 32 bit value to be written to the mask/data register where + * the upper 16 bits is the mask and lower 16 bits is the data + */ + state = !!state; + state = ~(1 << (bank_pin_num + ZYNQ_GPIO_MID_PIN_NUM)) & + ((state << bank_pin_num) | ZYNQ_GPIO_UPPER_MASK); + + writel_relaxed(state, gpio->base_addr + reg_offset); +} + +/** + * zynq_gpio_dir_in - Set the direction of the specified GPIO pin as input + * @chip: gpio_chip instance to be worked on + * @pin: gpio pin number within the device + * + * This function uses the read-modify-write sequence to set the direction of + * the gpio pin as input. + * + * Return: 0 always + */ +static int zynq_gpio_dir_in(struct gpio_chip *chip, unsigned int pin) +{ + u32 reg; + unsigned int bank_num, bank_pin_num; + struct zynq_gpio *gpio = container_of(chip, struct zynq_gpio, chip); + + zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num); + + /* bank 0 pins 7 and 8 are special and cannot be used as inputs */ + if (bank_num == 0 && (bank_pin_num == 7 || bank_pin_num == 8)) + return -EINVAL; + + /* clear the bit in direction mode reg to set the pin as input */ + reg = readl_relaxed(gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num)); + reg &= ~BIT(bank_pin_num); + writel_relaxed(reg, gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num)); + + return 0; +} + +/** + * zynq_gpio_dir_out - Set the direction of the specified GPIO pin as output + * @chip: gpio_chip instance to be worked on + * @pin: gpio pin number within the device + * @state: value to be written to specified pin + * + * This function sets the direction of specified GPIO pin as output, configures + * the Output Enable register for the pin and uses zynq_gpio_set to set + * the state of the pin to the value specified. + * + * Return: 0 always + */ +static int zynq_gpio_dir_out(struct gpio_chip *chip, unsigned int pin, + int state) +{ + u32 reg; + unsigned int bank_num, bank_pin_num; + struct zynq_gpio *gpio = container_of(chip, struct zynq_gpio, chip); + + zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num); + + /* set the GPIO pin as output */ + reg = readl_relaxed(gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num)); + reg |= BIT(bank_pin_num); + writel_relaxed(reg, gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num)); + + /* configure the output enable reg for the pin */ + reg = readl_relaxed(gpio->base_addr + ZYNQ_GPIO_OUTEN_OFFSET(bank_num)); + reg |= BIT(bank_pin_num); + writel_relaxed(reg, gpio->base_addr + ZYNQ_GPIO_OUTEN_OFFSET(bank_num)); + + /* set the state of the pin */ + zynq_gpio_set_value(chip, pin, state); + return 0; +} + +/** + * zynq_gpio_irq_mask - Disable the interrupts for a gpio pin + * @irq_data: per irq and chip data passed down to chip functions + * + * This function calculates gpio pin number from irq number and sets the + * bit in the Interrupt Disable register of the corresponding bank to disable + * interrupts for that pin. + */ +static void zynq_gpio_irq_mask(struct irq_data *irq_data) +{ + unsigned int device_pin_num, bank_num, bank_pin_num; + struct zynq_gpio *gpio = irq_data_get_irq_chip_data(irq_data); + + device_pin_num = irq_data->hwirq; + zynq_gpio_get_bank_pin(device_pin_num, &bank_num, &bank_pin_num); + writel_relaxed(BIT(bank_pin_num), + gpio->base_addr + ZYNQ_GPIO_INTDIS_OFFSET(bank_num)); +} + +/** + * zynq_gpio_irq_unmask - Enable the interrupts for a gpio pin + * @irq_data: irq data containing irq number of gpio pin for the interrupt + * to enable + * + * This function calculates the gpio pin number from irq number and sets the + * bit in the Interrupt Enable register of the corresponding bank to enable + * interrupts for that pin. + */ +static void zynq_gpio_irq_unmask(struct irq_data *irq_data) +{ + unsigned int device_pin_num, bank_num, bank_pin_num; + struct zynq_gpio *gpio = irq_data_get_irq_chip_data(irq_data); + + device_pin_num = irq_data->hwirq; + zynq_gpio_get_bank_pin(device_pin_num, &bank_num, &bank_pin_num); + writel_relaxed(BIT(bank_pin_num), + gpio->base_addr + ZYNQ_GPIO_INTEN_OFFSET(bank_num)); +} + +/** + * zynq_gpio_irq_ack - Acknowledge the interrupt of a gpio pin + * @irq_data: irq data containing irq number of gpio pin for the interrupt + * to ack + * + * This function calculates gpio pin number from irq number and sets the bit + * in the Interrupt Status Register of the corresponding bank, to ACK the irq. + */ +static void zynq_gpio_irq_ack(struct irq_data *irq_data) +{ + unsigned int device_pin_num, bank_num, bank_pin_num; + struct zynq_gpio *gpio = irq_data_get_irq_chip_data(irq_data); + + device_pin_num = irq_data->hwirq; + zynq_gpio_get_bank_pin(device_pin_num, &bank_num, &bank_pin_num); + writel_relaxed(BIT(bank_pin_num), + gpio->base_addr + ZYNQ_GPIO_INTSTS_OFFSET(bank_num)); +} + +/** + * zynq_gpio_irq_enable - Enable the interrupts for a gpio pin + * @irq_data: irq data containing irq number of gpio pin for the interrupt + * to enable + * + * Clears the INTSTS bit and unmasks the given interrrupt. + */ +static void zynq_gpio_irq_enable(struct irq_data *irq_data) +{ + /* + * The Zynq GPIO controller does not disable interrupt detection when + * the interrupt is masked and only disables the propagation of the + * interrupt. This means when the controller detects an interrupt + * condition while the interrupt is logically disabled it will propagate + * that interrupt event once the interrupt is enabled. This will cause + * the interrupt consumer to see spurious interrupts to prevent this + * first make sure that the interrupt is not asserted and then enable + * it. + */ + zynq_gpio_irq_ack(irq_data); + zynq_gpio_irq_unmask(irq_data); +} + +/** + * zynq_gpio_set_irq_type - Set the irq type for a gpio pin + * @irq_data: irq data containing irq number of gpio pin + * @type: interrupt type that is to be set for the gpio pin + * + * This function gets the gpio pin number and its bank from the gpio pin number + * and configures the INT_TYPE, INT_POLARITY and INT_ANY registers. + * + * Return: 0, negative error otherwise. + * TYPE-EDGE_RISING, INT_TYPE - 1, INT_POLARITY - 1, INT_ANY - 0; + * TYPE-EDGE_FALLING, INT_TYPE - 1, INT_POLARITY - 0, INT_ANY - 0; + * TYPE-EDGE_BOTH, INT_TYPE - 1, INT_POLARITY - NA, INT_ANY - 1; + * TYPE-LEVEL_HIGH, INT_TYPE - 0, INT_POLARITY - 1, INT_ANY - NA; + * TYPE-LEVEL_LOW, INT_TYPE - 0, INT_POLARITY - 0, INT_ANY - NA + */ +static int zynq_gpio_set_irq_type(struct irq_data *irq_data, unsigned int type) +{ + u32 int_type, int_pol, int_any; + unsigned int device_pin_num, bank_num, bank_pin_num; + struct zynq_gpio *gpio = irq_data_get_irq_chip_data(irq_data); + + device_pin_num = irq_data->hwirq; + zynq_gpio_get_bank_pin(device_pin_num, &bank_num, &bank_pin_num); + + int_type = readl_relaxed(gpio->base_addr + + ZYNQ_GPIO_INTTYPE_OFFSET(bank_num)); + int_pol = readl_relaxed(gpio->base_addr + + ZYNQ_GPIO_INTPOL_OFFSET(bank_num)); + int_any = readl_relaxed(gpio->base_addr + + ZYNQ_GPIO_INTANY_OFFSET(bank_num)); + + /* + * based on the type requested, configure the INT_TYPE, INT_POLARITY + * and INT_ANY registers + */ + switch (type) { + case IRQ_TYPE_EDGE_RISING: + int_type |= BIT(bank_pin_num); + int_pol |= BIT(bank_pin_num); + int_any &= ~BIT(bank_pin_num); + break; + case IRQ_TYPE_EDGE_FALLING: + int_type |= BIT(bank_pin_num); + int_pol &= ~BIT(bank_pin_num); + int_any &= ~BIT(bank_pin_num); + break; + case IRQ_TYPE_EDGE_BOTH: + int_type |= BIT(bank_pin_num); + int_any |= BIT(bank_pin_num); + break; + case IRQ_TYPE_LEVEL_HIGH: + int_type &= ~BIT(bank_pin_num); + int_pol |= BIT(bank_pin_num); + break; + case IRQ_TYPE_LEVEL_LOW: + int_type &= ~BIT(bank_pin_num); + int_pol &= ~BIT(bank_pin_num); + break; + default: + return -EINVAL; + } + + writel_relaxed(int_type, + gpio->base_addr + ZYNQ_GPIO_INTTYPE_OFFSET(bank_num)); + writel_relaxed(int_pol, + gpio->base_addr + ZYNQ_GPIO_INTPOL_OFFSET(bank_num)); + writel_relaxed(int_any, + gpio->base_addr + ZYNQ_GPIO_INTANY_OFFSET(bank_num)); + + if (type & IRQ_TYPE_LEVEL_MASK) { + __irq_set_chip_handler_name_locked(irq_data->irq, + &zynq_gpio_level_irqchip, handle_fasteoi_irq, NULL); + } else { + __irq_set_chip_handler_name_locked(irq_data->irq, + &zynq_gpio_edge_irqchip, handle_level_irq, NULL); + } + + return 0; +} + +static int zynq_gpio_set_wake(struct irq_data *data, unsigned int on) +{ + struct zynq_gpio *gpio = irq_data_get_irq_chip_data(data); + + irq_set_irq_wake(gpio->irq, on); + + return 0; +} + +/* irq chip descriptor */ +static struct irq_chip zynq_gpio_level_irqchip = { + .name = DRIVER_NAME, + .irq_enable = zynq_gpio_irq_enable, + .irq_eoi = zynq_gpio_irq_ack, + .irq_mask = zynq_gpio_irq_mask, + .irq_unmask = zynq_gpio_irq_unmask, + .irq_set_type = zynq_gpio_set_irq_type, + .irq_set_wake = zynq_gpio_set_wake, + .flags = IRQCHIP_EOI_THREADED | IRQCHIP_EOI_IF_HANDLED | + IRQCHIP_MASK_ON_SUSPEND, +}; + +static struct irq_chip zynq_gpio_edge_irqchip = { + .name = DRIVER_NAME, + .irq_enable = zynq_gpio_irq_enable, + .irq_ack = zynq_gpio_irq_ack, + .irq_mask = zynq_gpio_irq_mask, + .irq_unmask = zynq_gpio_irq_unmask, + .irq_set_type = zynq_gpio_set_irq_type, + .irq_set_wake = zynq_gpio_set_wake, + .flags = IRQCHIP_MASK_ON_SUSPEND, +}; + +static void zynq_gpio_handle_bank_irq(struct zynq_gpio *gpio, + unsigned int bank_num, + unsigned long pending) +{ + unsigned int bank_offset = zynq_gpio_bank_offset[bank_num]; + struct irq_domain *irqdomain = gpio->chip.irqdomain; + int offset; + + if (!pending) + return; + + for_each_set_bit(offset, &pending, 32) { + unsigned int gpio_irq; + + gpio_irq = irq_find_mapping(irqdomain, offset + bank_offset); + generic_handle_irq(gpio_irq); + } +} + +/** + * zynq_gpio_irqhandler - IRQ handler for the gpio banks of a gpio device + * @irq: irq number of the gpio bank where interrupt has occurred + * @desc: irq descriptor instance of the 'irq' + * + * This function reads the Interrupt Status Register of each bank to get the + * gpio pin number which has triggered an interrupt. It then acks the triggered + * interrupt and calls the pin specific handler set by the higher layer + * application for that pin. + * Note: A bug is reported if no handler is set for the gpio pin. + */ +static void zynq_gpio_irqhandler(unsigned int irq, struct irq_desc *desc) +{ + u32 int_sts, int_enb; + unsigned int bank_num; + struct zynq_gpio *gpio = irq_get_handler_data(irq); + struct irq_chip *irqchip = irq_desc_get_chip(desc); + + chained_irq_enter(irqchip, desc); + + for (bank_num = 0; bank_num < ZYNQ_GPIO_MAX_BANK; bank_num++) { + int_sts = readl_relaxed(gpio->base_addr + + ZYNQ_GPIO_INTSTS_OFFSET(bank_num)); + int_enb = readl_relaxed(gpio->base_addr + + ZYNQ_GPIO_INTMASK_OFFSET(bank_num)); + zynq_gpio_handle_bank_irq(gpio, bank_num, int_sts & ~int_enb); + } + + chained_irq_exit(irqchip, desc); +} + +static int __maybe_unused zynq_gpio_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + int irq = platform_get_irq(pdev, 0); + struct irq_data *data = irq_get_irq_data(irq); + + if (!irqd_is_wakeup_set(data)) + return pm_runtime_force_suspend(dev); + + return 0; +} + +static int __maybe_unused zynq_gpio_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + int irq = platform_get_irq(pdev, 0); + struct irq_data *data = irq_get_irq_data(irq); + + if (!irqd_is_wakeup_set(data)) + return pm_runtime_force_resume(dev); + + return 0; +} + +static int __maybe_unused zynq_gpio_runtime_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct zynq_gpio *gpio = platform_get_drvdata(pdev); + + clk_disable_unprepare(gpio->clk); + + return 0; +} + +static int __maybe_unused zynq_gpio_runtime_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct zynq_gpio *gpio = platform_get_drvdata(pdev); + + return clk_prepare_enable(gpio->clk); +} + +static int zynq_gpio_request(struct gpio_chip *chip, unsigned offset) +{ + int ret; + + ret = pm_runtime_get_sync(chip->dev); + + /* + * If the device is already active pm_runtime_get() will return 1 on + * success, but gpio_request still needs to return 0. + */ + return ret < 0 ? ret : 0; +} + +static void zynq_gpio_free(struct gpio_chip *chip, unsigned offset) +{ + pm_runtime_put(chip->dev); +} + +static const struct dev_pm_ops zynq_gpio_dev_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(zynq_gpio_suspend, zynq_gpio_resume) + SET_RUNTIME_PM_OPS(zynq_gpio_runtime_suspend, + zynq_gpio_runtime_resume, NULL) +}; + +/** + * zynq_gpio_probe - Initialization method for a zynq_gpio device + * @pdev: platform device instance + * + * This function allocates memory resources for the gpio device and registers + * all the banks of the device. It will also set up interrupts for the gpio + * pins. + * Note: Interrupts are disabled for all the banks during initialization. + * + * Return: 0 on success, negative error otherwise. + */ +static int zynq_gpio_probe(struct platform_device *pdev) +{ + int ret, bank_num; + struct zynq_gpio *gpio; + struct gpio_chip *chip; + struct resource *res; + + gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL); + if (!gpio) + return -ENOMEM; + + platform_set_drvdata(pdev, gpio); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + gpio->base_addr = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(gpio->base_addr)) + return PTR_ERR(gpio->base_addr); + + gpio->irq = platform_get_irq(pdev, 0); + if (gpio->irq < 0) { + dev_err(&pdev->dev, "invalid IRQ\n"); + return gpio->irq; + } + + /* configure the gpio chip */ + chip = &gpio->chip; + chip->label = "zynq_gpio"; + chip->owner = THIS_MODULE; + chip->dev = &pdev->dev; + chip->get = zynq_gpio_get_value; + chip->set = zynq_gpio_set_value; + chip->request = zynq_gpio_request; + chip->free = zynq_gpio_free; + chip->direction_input = zynq_gpio_dir_in; + chip->direction_output = zynq_gpio_dir_out; + chip->base = -1; + chip->ngpio = ZYNQ_GPIO_NR_GPIOS; + + /* Enable GPIO clock */ + gpio->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(gpio->clk)) { + dev_err(&pdev->dev, "input clock not found.\n"); + return PTR_ERR(gpio->clk); + } + ret = clk_prepare_enable(gpio->clk); + if (ret) { + dev_err(&pdev->dev, "Unable to enable clock.\n"); + return ret; + } + + /* report a bug if gpio chip registration fails */ + ret = gpiochip_add(chip); + if (ret) { + dev_err(&pdev->dev, "Failed to add gpio chip\n"); + goto err_disable_clk; + } + + /* disable interrupts for all banks */ + for (bank_num = 0; bank_num < ZYNQ_GPIO_MAX_BANK; bank_num++) + writel_relaxed(ZYNQ_GPIO_IXR_DISABLE_ALL, gpio->base_addr + + ZYNQ_GPIO_INTDIS_OFFSET(bank_num)); + + ret = gpiochip_irqchip_add(chip, &zynq_gpio_edge_irqchip, 0, + handle_level_irq, IRQ_TYPE_NONE); + if (ret) { + dev_err(&pdev->dev, "Failed to add irq chip\n"); + goto err_rm_gpiochip; + } + + gpiochip_set_chained_irqchip(chip, &zynq_gpio_edge_irqchip, gpio->irq, + zynq_gpio_irqhandler); + + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + + return 0; + +err_rm_gpiochip: + gpiochip_remove(chip); +err_disable_clk: + clk_disable_unprepare(gpio->clk); + + return ret; +} + +/** + * zynq_gpio_remove - Driver removal function + * @pdev: platform device instance + * + * Return: 0 always + */ +static int zynq_gpio_remove(struct platform_device *pdev) +{ + struct zynq_gpio *gpio = platform_get_drvdata(pdev); + + pm_runtime_get_sync(&pdev->dev); + gpiochip_remove(&gpio->chip); + clk_disable_unprepare(gpio->clk); + device_set_wakeup_capable(&pdev->dev, 0); + return 0; +} + +static struct of_device_id zynq_gpio_of_match[] = { + { .compatible = "xlnx,zynq-gpio-1.0", }, + { /* end of table */ } +}; +MODULE_DEVICE_TABLE(of, zynq_gpio_of_match); + +static struct platform_driver zynq_gpio_driver = { + .driver = { + .name = DRIVER_NAME, + .pm = &zynq_gpio_dev_pm_ops, + .of_match_table = zynq_gpio_of_match, + }, + .probe = zynq_gpio_probe, + .remove = zynq_gpio_remove, +}; + +/** + * zynq_gpio_init - Initial driver registration call + * + * Return: value from platform_driver_register + */ +static int __init zynq_gpio_init(void) +{ + return platform_driver_register(&zynq_gpio_driver); +} +postcore_initcall(zynq_gpio_init); + +MODULE_AUTHOR("Xilinx Inc."); +MODULE_DESCRIPTION("Zynq GPIO driver"); +MODULE_LICENSE("GPL"); |