diff options
Diffstat (limited to 'drivers/gpio/gpio-vt8500.c')
| -rw-r--r-- | drivers/gpio/gpio-vt8500.c | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-vt8500.c b/drivers/gpio/gpio-vt8500.c new file mode 100644 index 00000000000..bcd8e4aa7c7 --- /dev/null +++ b/drivers/gpio/gpio-vt8500.c @@ -0,0 +1,316 @@ +/* drivers/gpio/gpio-vt8500.c + * + * Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz> + * Based on arch/arm/mach-vt8500/gpio.c: + * - Copyright (C) 2010 Alexey Charkov <alchark@gmail.com> + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * 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/module.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/gpio.h> +#include <linux/platform_device.h> +#include <linux/bitops.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/of_device.h> + +/* + We handle GPIOs by bank, each bank containing up to 32 GPIOs covered + by one set of registers (although not all may be valid). + + Because different SoC's have different register offsets, we pass the + register offsets as data in vt8500_gpio_dt_ids[]. + + A value of NO_REG is used to indicate that this register is not + supported. Only used for ->en at the moment. +*/ + +#define NO_REG 0xFFFF + +/* + * struct vt8500_gpio_bank_regoffsets + * @en: offset to enable register of the bank + * @dir: offset to direction register of the bank + * @data_out: offset to the data out register of the bank + * @data_in: offset to the data in register of the bank + * @ngpio: highest valid pin in this bank + */ + +struct vt8500_gpio_bank_regoffsets { + unsigned int en; + unsigned int dir; + unsigned int data_out; + unsigned int data_in; + unsigned char ngpio; +}; + +struct vt8500_gpio_data { + unsigned int num_banks; + struct vt8500_gpio_bank_regoffsets banks[]; +}; + +#define VT8500_BANK(__en, __dir, __out, __in, __ngpio) \ +{ \ + .en = __en, \ + .dir = __dir, \ + .data_out = __out, \ + .data_in = __in, \ + .ngpio = __ngpio, \ +} + +static struct vt8500_gpio_data vt8500_data = { + .num_banks = 7, + .banks = { + VT8500_BANK(0x00, 0x20, 0x40, 0x60, 26), + VT8500_BANK(0x04, 0x24, 0x44, 0x64, 28), + VT8500_BANK(0x08, 0x28, 0x48, 0x68, 31), + VT8500_BANK(0x0C, 0x2C, 0x4C, 0x6C, 19), + VT8500_BANK(0x10, 0x30, 0x50, 0x70, 19), + VT8500_BANK(0x14, 0x34, 0x54, 0x74, 23), + VT8500_BANK(NO_REG, 0x3C, 0x5C, 0x7C, 9), + }, +}; + +static struct vt8500_gpio_data wm8505_data = { + .num_banks = 10, + .banks = { + VT8500_BANK(0x40, 0x68, 0x90, 0xB8, 8), + VT8500_BANK(0x44, 0x6C, 0x94, 0xBC, 32), + VT8500_BANK(0x48, 0x70, 0x98, 0xC0, 6), + VT8500_BANK(0x4C, 0x74, 0x9C, 0xC4, 16), + VT8500_BANK(0x50, 0x78, 0xA0, 0xC8, 25), + VT8500_BANK(0x54, 0x7C, 0xA4, 0xCC, 5), + VT8500_BANK(0x58, 0x80, 0xA8, 0xD0, 5), + VT8500_BANK(0x5C, 0x84, 0xAC, 0xD4, 12), + VT8500_BANK(0x60, 0x88, 0xB0, 0xD8, 16), + VT8500_BANK(0x64, 0x8C, 0xB4, 0xDC, 22), + }, +}; + +/* + * No information about which bits are valid so we just make + * them all available until its figured out. + */ +static struct vt8500_gpio_data wm8650_data = { + .num_banks = 9, + .banks = { + VT8500_BANK(0x40, 0x80, 0xC0, 0x00, 32), + VT8500_BANK(0x44, 0x84, 0xC4, 0x04, 32), + VT8500_BANK(0x48, 0x88, 0xC8, 0x08, 32), + VT8500_BANK(0x4C, 0x8C, 0xCC, 0x0C, 32), + VT8500_BANK(0x50, 0x90, 0xD0, 0x10, 32), + VT8500_BANK(0x54, 0x94, 0xD4, 0x14, 32), + VT8500_BANK(0x58, 0x98, 0xD8, 0x18, 32), + VT8500_BANK(0x5C, 0x9C, 0xDC, 0x1C, 32), + VT8500_BANK(0x7C, 0xBC, 0xFC, 0x3C, 32), + }, +}; + +struct vt8500_gpio_chip { + struct gpio_chip chip; + + const struct vt8500_gpio_bank_regoffsets *regs; + void __iomem *base; +}; + + +#define to_vt8500(__chip) container_of(__chip, struct vt8500_gpio_chip, chip) + +static int vt8500_gpio_request(struct gpio_chip *chip, unsigned offset) +{ + u32 val; + struct vt8500_gpio_chip *vt8500_chip = to_vt8500(chip); + + if (vt8500_chip->regs->en == NO_REG) + return 0; + + val = readl_relaxed(vt8500_chip->base + vt8500_chip->regs->en); + val |= BIT(offset); + writel_relaxed(val, vt8500_chip->base + vt8500_chip->regs->en); + + return 0; +} + +static void vt8500_gpio_free(struct gpio_chip *chip, unsigned offset) +{ + struct vt8500_gpio_chip *vt8500_chip = to_vt8500(chip); + u32 val; + + if (vt8500_chip->regs->en == NO_REG) + return; + + val = readl_relaxed(vt8500_chip->base + vt8500_chip->regs->en); + val &= ~BIT(offset); + writel_relaxed(val, vt8500_chip->base + vt8500_chip->regs->en); +} + +static int vt8500_gpio_direction_input(struct gpio_chip *chip, unsigned offset) +{ + struct vt8500_gpio_chip *vt8500_chip = to_vt8500(chip); + + u32 val = readl_relaxed(vt8500_chip->base + vt8500_chip->regs->dir); + val &= ~BIT(offset); + writel_relaxed(val, vt8500_chip->base + vt8500_chip->regs->dir); + + return 0; +} + +static int vt8500_gpio_direction_output(struct gpio_chip *chip, unsigned offset, + int value) +{ + struct vt8500_gpio_chip *vt8500_chip = to_vt8500(chip); + + u32 val = readl_relaxed(vt8500_chip->base + vt8500_chip->regs->dir); + val |= BIT(offset); + writel_relaxed(val, vt8500_chip->base + vt8500_chip->regs->dir); + + if (value) { + val = readl_relaxed(vt8500_chip->base + + vt8500_chip->regs->data_out); + val |= BIT(offset); + writel_relaxed(val, vt8500_chip->base + + vt8500_chip->regs->data_out); + } + return 0; +} + +static int vt8500_gpio_get_value(struct gpio_chip *chip, unsigned offset) +{ + struct vt8500_gpio_chip *vt8500_chip = to_vt8500(chip); + + return (readl_relaxed(vt8500_chip->base + vt8500_chip->regs->data_in) >> + offset) & 1; +} + +static void vt8500_gpio_set_value(struct gpio_chip *chip, unsigned offset, + int value) +{ + struct vt8500_gpio_chip *vt8500_chip = to_vt8500(chip); + + u32 val = readl_relaxed(vt8500_chip->base + + vt8500_chip->regs->data_out); + if (value) + val |= BIT(offset); + else + val &= ~BIT(offset); + + writel_relaxed(val, vt8500_chip->base + vt8500_chip->regs->data_out); +} + +static int vt8500_of_xlate(struct gpio_chip *gc, + const struct of_phandle_args *gpiospec, u32 *flags) +{ + /* bank if specificed in gpiospec->args[0] */ + if (flags) + *flags = gpiospec->args[2]; + + return gpiospec->args[1]; +} + +static int vt8500_add_chips(struct platform_device *pdev, void __iomem *base, + const struct vt8500_gpio_data *data) +{ + struct vt8500_gpio_chip *vtchip; + struct gpio_chip *chip; + int i; + int pin_cnt = 0; + + vtchip = devm_kzalloc(&pdev->dev, + sizeof(struct vt8500_gpio_chip) * data->num_banks, + GFP_KERNEL); + if (!vtchip) { + pr_err("%s: failed to allocate chip memory\n", __func__); + return -ENOMEM; + } + + for (i = 0; i < data->num_banks; i++) { + vtchip[i].base = base; + vtchip[i].regs = &data->banks[i]; + + chip = &vtchip[i].chip; + + chip->of_xlate = vt8500_of_xlate; + chip->of_gpio_n_cells = 3; + chip->of_node = pdev->dev.of_node; + + chip->request = vt8500_gpio_request; + chip->free = vt8500_gpio_free; + chip->direction_input = vt8500_gpio_direction_input; + chip->direction_output = vt8500_gpio_direction_output; + chip->get = vt8500_gpio_get_value; + chip->set = vt8500_gpio_set_value; + chip->can_sleep = 0; + chip->base = pin_cnt; + chip->ngpio = data->banks[i].ngpio; + + pin_cnt += data->banks[i].ngpio; + + gpiochip_add(chip); + } + return 0; +} + +static struct of_device_id vt8500_gpio_dt_ids[] = { + { .compatible = "via,vt8500-gpio", .data = &vt8500_data, }, + { .compatible = "wm,wm8505-gpio", .data = &wm8505_data, }, + { .compatible = "wm,wm8650-gpio", .data = &wm8650_data, }, + { /* Sentinel */ }, +}; + +static int __devinit vt8500_gpio_probe(struct platform_device *pdev) +{ + void __iomem *gpio_base; + struct device_node *np; + const struct of_device_id *of_id = + of_match_device(vt8500_gpio_dt_ids, &pdev->dev); + + if (!of_id) { + dev_err(&pdev->dev, "Failed to find gpio controller\n"); + return -ENODEV; + } + + np = pdev->dev.of_node; + if (!np) { + dev_err(&pdev->dev, "Missing GPIO description in devicetree\n"); + return -EFAULT; + } + + gpio_base = of_iomap(np, 0); + if (!gpio_base) { + dev_err(&pdev->dev, "Unable to map GPIO registers\n"); + of_node_put(np); + return -ENOMEM; + } + + vt8500_add_chips(pdev, gpio_base, of_id->data); + + return 0; +} + +static struct platform_driver vt8500_gpio_driver = { + .probe = vt8500_gpio_probe, + .driver = { + .name = "vt8500-gpio", + .owner = THIS_MODULE, + .of_match_table = vt8500_gpio_dt_ids, + }, +}; + +module_platform_driver(vt8500_gpio_driver); + +MODULE_DESCRIPTION("VT8500 GPIO Driver"); +MODULE_AUTHOR("Tony Prisk <linux@prisktech.co.nz>"); +MODULE_LICENSE("GPL v2"); +MODULE_DEVICE_TABLE(of, vt8500_gpio_dt_ids); |