diff options
Diffstat (limited to 'drivers/gpio/gpio-tz1090-pdc.c')
| -rw-r--r-- | drivers/gpio/gpio-tz1090-pdc.c | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-tz1090-pdc.c b/drivers/gpio/gpio-tz1090-pdc.c new file mode 100644 index 000000000000..f512da299b3d --- /dev/null +++ b/drivers/gpio/gpio-tz1090-pdc.c @@ -0,0 +1,243 @@ +/* + * Toumaz Xenif TZ1090 PDC GPIO handling. + * + * Copyright (C) 2012-2013 Imagination Technologies Ltd. + * + * 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. + */ + +#include <linux/bitops.h> +#include <linux/gpio.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of_irq.h> +#include <linux/pinctrl/consumer.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/syscore_ops.h> +#include <asm/global_lock.h> + +/* Register offsets from SOC_GPIO_CONTROL0 */ +#define REG_SOC_GPIO_CONTROL0 0x00 +#define REG_SOC_GPIO_CONTROL1 0x04 +#define REG_SOC_GPIO_CONTROL2 0x08 +#define REG_SOC_GPIO_CONTROL3 0x0c +#define REG_SOC_GPIO_STATUS 0x80 + +/* PDC GPIOs go after normal GPIOs */ +#define GPIO_PDC_BASE 90 +#define GPIO_PDC_NGPIO 7 + +/* Out of PDC gpios, only syswakes have irqs */ +#define GPIO_PDC_IRQ_FIRST 2 +#define GPIO_PDC_NIRQ 3 + +/** + * struct tz1090_pdc_gpio - GPIO bank private data + * @chip: Generic GPIO chip for GPIO bank + * @reg: Base of registers, offset for this GPIO bank + * @irq: IRQ numbers for Syswake GPIOs + * + * This is the main private data for the PDC GPIO driver. It encapsulates a + * gpio_chip, and the callbacks for the gpio_chip can access the private data + * with the to_pdc() macro below. + */ +struct tz1090_pdc_gpio { + struct gpio_chip chip; + void __iomem *reg; + int irq[GPIO_PDC_NIRQ]; +}; +#define to_pdc(c) container_of(c, struct tz1090_pdc_gpio, chip) + +/* Register accesses into the PDC MMIO area */ + +static inline void pdc_write(struct tz1090_pdc_gpio *priv, unsigned int reg_offs, + unsigned int data) +{ + writel(data, priv->reg + reg_offs); +} + +static inline unsigned int pdc_read(struct tz1090_pdc_gpio *priv, + unsigned int reg_offs) +{ + return readl(priv->reg + reg_offs); +} + +/* Generic GPIO interface */ + +static int tz1090_pdc_gpio_direction_input(struct gpio_chip *chip, + unsigned int offset) +{ + struct tz1090_pdc_gpio *priv = to_pdc(chip); + u32 value; + int lstat; + + __global_lock2(lstat); + value = pdc_read(priv, REG_SOC_GPIO_CONTROL1); + value |= BIT(offset); + pdc_write(priv, REG_SOC_GPIO_CONTROL1, value); + __global_unlock2(lstat); + + return 0; +} + +static int tz1090_pdc_gpio_direction_output(struct gpio_chip *chip, + unsigned int offset, + int output_value) +{ + struct tz1090_pdc_gpio *priv = to_pdc(chip); + u32 value; + int lstat; + + __global_lock2(lstat); + /* EXT_POWER doesn't seem to have an output value bit */ + if (offset < 6) { + value = pdc_read(priv, REG_SOC_GPIO_CONTROL0); + if (output_value) + value |= BIT(offset); + else + value &= ~BIT(offset); + pdc_write(priv, REG_SOC_GPIO_CONTROL0, value); + } + + value = pdc_read(priv, REG_SOC_GPIO_CONTROL1); + value &= ~BIT(offset); + pdc_write(priv, REG_SOC_GPIO_CONTROL1, value); + __global_unlock2(lstat); + + return 0; +} + +static int tz1090_pdc_gpio_get(struct gpio_chip *chip, unsigned int offset) +{ + struct tz1090_pdc_gpio *priv = to_pdc(chip); + return pdc_read(priv, REG_SOC_GPIO_STATUS) & BIT(offset); +} + +static void tz1090_pdc_gpio_set(struct gpio_chip *chip, unsigned int offset, + int output_value) +{ + struct tz1090_pdc_gpio *priv = to_pdc(chip); + u32 value; + int lstat; + + /* EXT_POWER doesn't seem to have an output value bit */ + if (offset >= 6) + return; + + __global_lock2(lstat); + value = pdc_read(priv, REG_SOC_GPIO_CONTROL0); + if (output_value) + value |= BIT(offset); + else + value &= ~BIT(offset); + pdc_write(priv, REG_SOC_GPIO_CONTROL0, value); + __global_unlock2(lstat); +} + +static int tz1090_pdc_gpio_request(struct gpio_chip *chip, unsigned int offset) +{ + return pinctrl_request_gpio(chip->base + offset); +} + +static void tz1090_pdc_gpio_free(struct gpio_chip *chip, unsigned int offset) +{ + pinctrl_free_gpio(chip->base + offset); +} + +static int tz1090_pdc_gpio_to_irq(struct gpio_chip *chip, unsigned int offset) +{ + struct tz1090_pdc_gpio *priv = to_pdc(chip); + unsigned int syswake = offset - GPIO_PDC_IRQ_FIRST; + int irq; + + /* only syswakes have irqs */ + if (syswake >= GPIO_PDC_NIRQ) + return -EINVAL; + + irq = priv->irq[syswake]; + if (!irq) + return -EINVAL; + + return irq; +} + +static int tz1090_pdc_gpio_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct resource *res_regs; + struct tz1090_pdc_gpio *priv; + unsigned int i; + + if (!np) { + dev_err(&pdev->dev, "must be instantiated via devicetree\n"); + return -ENOENT; + } + + res_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res_regs) { + dev_err(&pdev->dev, "cannot find registers resource\n"); + return -ENOENT; + } + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) { + dev_err(&pdev->dev, "unable to allocate driver data\n"); + return -ENOMEM; + } + + /* Ioremap the registers */ + priv->reg = devm_ioremap(&pdev->dev, res_regs->start, + res_regs->end - res_regs->start); + if (!priv->reg) { + dev_err(&pdev->dev, "unable to ioremap registers\n"); + return -ENOMEM; + } + + /* Set up GPIO chip */ + priv->chip.label = "tz1090-pdc-gpio"; + priv->chip.dev = &pdev->dev; + priv->chip.direction_input = tz1090_pdc_gpio_direction_input; + priv->chip.direction_output = tz1090_pdc_gpio_direction_output; + priv->chip.get = tz1090_pdc_gpio_get; + priv->chip.set = tz1090_pdc_gpio_set; + priv->chip.free = tz1090_pdc_gpio_free; + priv->chip.request = tz1090_pdc_gpio_request; + priv->chip.to_irq = tz1090_pdc_gpio_to_irq; + priv->chip.of_node = np; + + /* GPIO numbering */ + priv->chip.base = GPIO_PDC_BASE; + priv->chip.ngpio = GPIO_PDC_NGPIO; + + /* Map the syswake irqs */ + for (i = 0; i < GPIO_PDC_NIRQ; ++i) + priv->irq[i] = irq_of_parse_and_map(np, i); + + /* Add the GPIO bank */ + gpiochip_add(&priv->chip); + + return 0; +} + +static struct of_device_id tz1090_pdc_gpio_of_match[] = { + { .compatible = "img,tz1090-pdc-gpio" }, + { }, +}; + +static struct platform_driver tz1090_pdc_gpio_driver = { + .driver = { + .name = "tz1090-pdc-gpio", + .owner = THIS_MODULE, + .of_match_table = tz1090_pdc_gpio_of_match, + }, + .probe = tz1090_pdc_gpio_probe, +}; + +static int __init tz1090_pdc_gpio_init(void) +{ + return platform_driver_register(&tz1090_pdc_gpio_driver); +} +subsys_initcall(tz1090_pdc_gpio_init); |