diff options
Diffstat (limited to 'drivers/pinctrl/pinctrl-digicolor.c')
| -rw-r--r-- | drivers/pinctrl/pinctrl-digicolor.c | 378 |
1 files changed, 378 insertions, 0 deletions
diff --git a/drivers/pinctrl/pinctrl-digicolor.c b/drivers/pinctrl/pinctrl-digicolor.c new file mode 100644 index 0000000..461fffc --- /dev/null +++ b/drivers/pinctrl/pinctrl-digicolor.c @@ -0,0 +1,378 @@ +/* + * Driver for Conexant Digicolor General Purpose Pin Mapping + * + * Author: Baruch Siach <baruch@tkos.co.il> + * + * Copyright (C) 2015 Paradox Innovation Ltd. + * + * 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. + * + * TODO: + * - GPIO interrupt support + * - Pin pad configuration (pull up/down, strength) + */ + +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/io.h> +#include <linux/gpio.h> +#include <linux/gpio/driver.h> +#include <linux/spinlock.h> +#include <linux/pinctrl/machine.h> +#include <linux/pinctrl/pinconf.h> +#include <linux/pinctrl/pinconf-generic.h> +#include <linux/pinctrl/pinctrl.h> +#include <linux/pinctrl/pinmux.h> +#include "pinctrl-utils.h" + +#define DRIVER_NAME "pinctrl-digicolor" + +#define GP_CLIENTSEL(clct) ((clct)*8 + 0x20) +#define GP_DRIVE0(clct) (GP_CLIENTSEL(clct) + 2) +#define GP_OUTPUT0(clct) (GP_CLIENTSEL(clct) + 3) +#define GP_INPUT(clct) (GP_CLIENTSEL(clct) + 6) + +#define PIN_COLLECTIONS ('R' - 'A' + 1) +#define PINS_PER_COLLECTION 8 +#define PINS_COUNT (PIN_COLLECTIONS * PINS_PER_COLLECTION) + +struct dc_pinmap { + void __iomem *regs; + struct device *dev; + struct pinctrl_dev *pctl; + + struct pinctrl_desc *desc; + const char *pin_names[PINS_COUNT]; + + struct gpio_chip chip; + spinlock_t lock; +}; + +static int dc_get_groups_count(struct pinctrl_dev *pctldev) +{ + return PINS_COUNT; +} + +static const char *dc_get_group_name(struct pinctrl_dev *pctldev, + unsigned selector) +{ + struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pctldev); + + /* Exactly one group per pin */ + return pmap->desc->pins[selector].name; +} + +static int dc_get_group_pins(struct pinctrl_dev *pctldev, unsigned selector, + const unsigned **pins, + unsigned *num_pins) +{ + struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pctldev); + + *pins = &pmap->desc->pins[selector].number; + *num_pins = 1; + + return 0; +} + +static struct pinctrl_ops dc_pinctrl_ops = { + .get_groups_count = dc_get_groups_count, + .get_group_name = dc_get_group_name, + .get_group_pins = dc_get_group_pins, + .dt_node_to_map = pinconf_generic_dt_node_to_map_pin, + .dt_free_map = pinctrl_utils_dt_free_map, +}; + +static const char *const dc_functions[] = { + "gpio", + "client_a", + "client_b", + "client_c", +}; + +static int dc_get_functions_count(struct pinctrl_dev *pctldev) +{ + return ARRAY_SIZE(dc_functions); +} + +static const char *dc_get_fname(struct pinctrl_dev *pctldev, unsigned selector) +{ + return dc_functions[selector]; +} + +static int dc_get_groups(struct pinctrl_dev *pctldev, unsigned selector, + const char * const **groups, + unsigned * const num_groups) +{ + struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pctldev); + + *groups = pmap->pin_names; + *num_groups = PINS_COUNT; + + return 0; +} + +static void dc_client_sel(int pin_num, int *reg, int *bit) +{ + *bit = (pin_num % PINS_PER_COLLECTION) * 2; + *reg = GP_CLIENTSEL(pin_num/PINS_PER_COLLECTION); + + if (*bit >= PINS_PER_COLLECTION) { + *bit -= PINS_PER_COLLECTION; + *reg += 1; + } +} + +static int dc_set_mux(struct pinctrl_dev *pctldev, unsigned selector, + unsigned group) +{ + struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pctldev); + int bit_off, reg_off; + u8 reg; + + dc_client_sel(group, ®_off, &bit_off); + + reg = readb_relaxed(pmap->regs + reg_off); + reg &= ~(3 << bit_off); + reg |= (selector << bit_off); + writeb_relaxed(reg, pmap->regs + reg_off); + + return 0; +} + +static int dc_pmx_request_gpio(struct pinctrl_dev *pcdev, + struct pinctrl_gpio_range *range, + unsigned offset) +{ + struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pcdev); + int bit_off, reg_off; + u8 reg; + + dc_client_sel(offset, ®_off, &bit_off); + + reg = readb_relaxed(pmap->regs + reg_off); + if ((reg & (3 << bit_off)) != 0) + return -EBUSY; + + return 0; +} + +static struct pinmux_ops dc_pmxops = { + .get_functions_count = dc_get_functions_count, + .get_function_name = dc_get_fname, + .get_function_groups = dc_get_groups, + .set_mux = dc_set_mux, + .gpio_request_enable = dc_pmx_request_gpio, +}; + +static int dc_gpio_request(struct gpio_chip *chip, unsigned gpio) +{ + return pinctrl_request_gpio(chip->base + gpio); +} + +static void dc_gpio_free(struct gpio_chip *chip, unsigned gpio) +{ + pinctrl_free_gpio(chip->base + gpio); +} + +static int dc_gpio_direction_input(struct gpio_chip *chip, unsigned gpio) +{ + struct dc_pinmap *pmap = container_of(chip, struct dc_pinmap, chip); + int reg_off = GP_DRIVE0(gpio/PINS_PER_COLLECTION); + int bit_off = gpio % PINS_PER_COLLECTION; + u8 drive; + unsigned long flags; + + spin_lock_irqsave(&pmap->lock, flags); + drive = readb_relaxed(pmap->regs + reg_off); + drive &= ~BIT(bit_off); + writeb_relaxed(drive, pmap->regs + reg_off); + spin_unlock_irqrestore(&pmap->lock, flags); + + return 0; +} + +static void dc_gpio_set(struct gpio_chip *chip, unsigned gpio, int value); + +static int dc_gpio_direction_output(struct gpio_chip *chip, unsigned gpio, + int value) +{ + struct dc_pinmap *pmap = container_of(chip, struct dc_pinmap, chip); + int reg_off = GP_DRIVE0(gpio/PINS_PER_COLLECTION); + int bit_off = gpio % PINS_PER_COLLECTION; + u8 drive; + unsigned long flags; + + dc_gpio_set(chip, gpio, value); + + spin_lock_irqsave(&pmap->lock, flags); + drive = readb_relaxed(pmap->regs + reg_off); + drive |= BIT(bit_off); + writeb_relaxed(drive, pmap->regs + reg_off); + spin_unlock_irqrestore(&pmap->lock, flags); + + return 0; +} + +static int dc_gpio_get(struct gpio_chip *chip, unsigned gpio) +{ + struct dc_pinmap *pmap = container_of(chip, struct dc_pinmap, chip); + int reg_off = GP_INPUT(gpio/PINS_PER_COLLECTION); + int bit_off = gpio % PINS_PER_COLLECTION; + u8 input; + + input = readb_relaxed(pmap->regs + reg_off); + + return !!(input & BIT(bit_off)); +} + +static void dc_gpio_set(struct gpio_chip *chip, unsigned gpio, int value) +{ + struct dc_pinmap *pmap = container_of(chip, struct dc_pinmap, chip); + int reg_off = GP_OUTPUT0(gpio/PINS_PER_COLLECTION); + int bit_off = gpio % PINS_PER_COLLECTION; + u8 output; + unsigned long flags; + + spin_lock_irqsave(&pmap->lock, flags); + output = readb_relaxed(pmap->regs + reg_off); + if (value) + output |= BIT(bit_off); + else + output &= ~BIT(bit_off); + writeb_relaxed(output, pmap->regs + reg_off); + spin_unlock_irqrestore(&pmap->lock, flags); +} + +static int dc_gpiochip_add(struct dc_pinmap *pmap, struct device_node *np) +{ + struct gpio_chip *chip = &pmap->chip; + int ret; + + chip->label = DRIVER_NAME; + chip->dev = pmap->dev; + chip->request = dc_gpio_request; + chip->free = dc_gpio_free; + chip->direction_input = dc_gpio_direction_input; + chip->direction_output = dc_gpio_direction_output; + chip->get = dc_gpio_get; + chip->set = dc_gpio_set; + chip->base = -1; + chip->ngpio = PINS_COUNT; + chip->of_node = np; + chip->of_gpio_n_cells = 2; + + spin_lock_init(&pmap->lock); + + ret = gpiochip_add(chip); + if (ret < 0) + return ret; + + ret = gpiochip_add_pin_range(chip, dev_name(pmap->dev), 0, 0, + PINS_COUNT); + if (ret < 0) { + gpiochip_remove(chip); + return ret; + } + + return 0; +} + +static int dc_pinctrl_probe(struct platform_device *pdev) +{ + struct dc_pinmap *pmap; + struct resource *r; + struct pinctrl_pin_desc *pins; + struct pinctrl_desc *pctl_desc; + char *pin_names; + int name_len = strlen("GP_xx") + 1; + int i, j, ret; + + pmap = devm_kzalloc(&pdev->dev, sizeof(*pmap), GFP_KERNEL); + if (!pmap) + return -ENOMEM; + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + pmap->regs = devm_ioremap_resource(&pdev->dev, r); + if (IS_ERR(pmap->regs)) + return PTR_ERR(pmap->regs); + + pins = devm_kzalloc(&pdev->dev, sizeof(*pins)*PINS_COUNT, GFP_KERNEL); + if (!pins) + return -ENOMEM; + pin_names = devm_kzalloc(&pdev->dev, name_len * PINS_COUNT, + GFP_KERNEL); + if (!pin_names) + return -ENOMEM; + + for (i = 0; i < PIN_COLLECTIONS; i++) { + for (j = 0; j < PINS_PER_COLLECTION; j++) { + int pin_id = i*PINS_PER_COLLECTION + j; + char *name = &pin_names[pin_id * name_len]; + + snprintf(name, name_len, "GP_%c%c", 'A'+i, '0'+j); + + pins[pin_id].number = pin_id; + pins[pin_id].name = name; + pmap->pin_names[pin_id] = name; + } + } + + pctl_desc = devm_kzalloc(&pdev->dev, sizeof(*pctl_desc), GFP_KERNEL); + if (!pctl_desc) + return -ENOMEM; + + pctl_desc->name = DRIVER_NAME, + pctl_desc->owner = THIS_MODULE, + pctl_desc->pctlops = &dc_pinctrl_ops, + pctl_desc->pmxops = &dc_pmxops, + pctl_desc->npins = PINS_COUNT; + pctl_desc->pins = pins; + pmap->desc = pctl_desc; + + pmap->dev = &pdev->dev; + + pmap->pctl = pinctrl_register(pctl_desc, &pdev->dev, pmap); + if (!pmap->pctl) { + dev_err(&pdev->dev, "pinctrl driver registration failed\n"); + return -EINVAL; + } + + ret = dc_gpiochip_add(pmap, pdev->dev.of_node); + if (ret < 0) { + pinctrl_unregister(pmap->pctl); + return ret; + } + + return 0; +} + +static int dc_pinctrl_remove(struct platform_device *pdev) +{ + struct dc_pinmap *pmap = platform_get_drvdata(pdev); + + pinctrl_unregister(pmap->pctl); + gpiochip_remove(&pmap->chip); + + return 0; +} + +static const struct of_device_id dc_pinctrl_ids[] = { + { .compatible = "cnxt,cx92755-pinctrl" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, dc_pinctrl_ids); + +static struct platform_driver dc_pinctrl_driver = { + .driver = { + .name = DRIVER_NAME, + .of_match_table = dc_pinctrl_ids, + }, + .probe = dc_pinctrl_probe, + .remove = dc_pinctrl_remove, +}; +module_platform_driver(dc_pinctrl_driver); |
