root/drivers/pinctrl/vt8500/pinctrl-wmt.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Pinctrl driver for the Wondermedia SoC's
 *
 * Copyright (c) 2013 Tony Prisk <linux@prisktech.co.nz>
 */

#include <linux/err.h>
#include <linux/gpio/driver.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/pinctrl/consumer.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 <linux/platform_device.h>
#include <linux/slab.h>

#include "pinctrl-wmt.h"

static inline void wmt_setbits(struct wmt_pinctrl_data *data, u32 reg,
                                 u32 mask)
{
        u32 val;

        val = readl_relaxed(data->base + reg);
        val |= mask;
        writel_relaxed(val, data->base + reg);
}

static inline void wmt_clearbits(struct wmt_pinctrl_data *data, u32 reg,
                                   u32 mask)
{
        u32 val;

        val = readl_relaxed(data->base + reg);
        val &= ~mask;
        writel_relaxed(val, data->base + reg);
}

enum wmt_func_sel {
        WMT_FSEL_GPIO_IN = 0,
        WMT_FSEL_GPIO_OUT = 1,
        WMT_FSEL_ALT = 2,
        WMT_FSEL_COUNT = 3,
};

static const char * const wmt_functions[WMT_FSEL_COUNT] = {
        [WMT_FSEL_GPIO_IN] = "gpio_in",
        [WMT_FSEL_GPIO_OUT] = "gpio_out",
        [WMT_FSEL_ALT] = "alt",
};

static int wmt_pmx_get_functions_count(struct pinctrl_dev *pctldev)
{
        return WMT_FSEL_COUNT;
}

static const char *wmt_pmx_get_function_name(struct pinctrl_dev *pctldev,
                                             unsigned selector)
{
        return wmt_functions[selector];
}

static int wmt_pmx_get_function_groups(struct pinctrl_dev *pctldev,
                                       unsigned selector,
                                       const char * const **groups,
                                       unsigned * const num_groups)
{
        struct wmt_pinctrl_data *data = pinctrl_dev_get_drvdata(pctldev);

        /* every pin does every function */
        *groups = data->groups;
        *num_groups = data->ngroups;

        return 0;
}

static int wmt_set_pinmux(struct wmt_pinctrl_data *data, unsigned func,
                          unsigned pin)
{
        u32 bank = WMT_BANK_FROM_PIN(pin);
        u32 bit = WMT_BIT_FROM_PIN(pin);
        u32 reg_en = data->banks[bank].reg_en;
        u32 reg_dir = data->banks[bank].reg_dir;

        if (reg_dir == NO_REG) {
                dev_err(data->dev, "pin:%d no direction register defined\n",
                        pin);
                return -EINVAL;
        }

        /*
         * If reg_en == NO_REG, we assume it is a dedicated GPIO and cannot be
         * disabled (as on VT8500) and that no alternate function is available.
         */
        switch (func) {
        case WMT_FSEL_GPIO_IN:
                if (reg_en != NO_REG)
                        wmt_setbits(data, reg_en, BIT(bit));
                wmt_clearbits(data, reg_dir, BIT(bit));
                break;
        case WMT_FSEL_GPIO_OUT:
                if (reg_en != NO_REG)
                        wmt_setbits(data, reg_en, BIT(bit));
                wmt_setbits(data, reg_dir, BIT(bit));
                break;
        case WMT_FSEL_ALT:
                if (reg_en == NO_REG) {
                        dev_err(data->dev, "pin:%d no alt function available\n",
                                pin);
                        return -EINVAL;
                }
                wmt_clearbits(data, reg_en, BIT(bit));
        }

        return 0;
}

static int wmt_pmx_set_mux(struct pinctrl_dev *pctldev,
                           unsigned func_selector,
                           unsigned group_selector)
{
        struct wmt_pinctrl_data *data = pinctrl_dev_get_drvdata(pctldev);
        u32 pinnum = data->pins[group_selector].number;

        return wmt_set_pinmux(data, func_selector, pinnum);
}

static void wmt_pmx_gpio_disable_free(struct pinctrl_dev *pctldev,
                                      struct pinctrl_gpio_range *range,
                                      unsigned offset)
{
        struct wmt_pinctrl_data *data = pinctrl_dev_get_drvdata(pctldev);

        /* disable by setting GPIO_IN */
        wmt_set_pinmux(data, WMT_FSEL_GPIO_IN, offset);
}

static int wmt_pmx_gpio_set_direction(struct pinctrl_dev *pctldev,
                                      struct pinctrl_gpio_range *range,
                                      unsigned offset,
                                      bool input)
{
        struct wmt_pinctrl_data *data = pinctrl_dev_get_drvdata(pctldev);

        wmt_set_pinmux(data, (input ? WMT_FSEL_GPIO_IN : WMT_FSEL_GPIO_OUT),
                       offset);

        return 0;
}

static const struct pinmux_ops wmt_pinmux_ops = {
        .get_functions_count = wmt_pmx_get_functions_count,
        .get_function_name = wmt_pmx_get_function_name,
        .get_function_groups = wmt_pmx_get_function_groups,
        .set_mux = wmt_pmx_set_mux,
        .gpio_disable_free = wmt_pmx_gpio_disable_free,
        .gpio_set_direction = wmt_pmx_gpio_set_direction,
};

static int wmt_get_groups_count(struct pinctrl_dev *pctldev)
{
        struct wmt_pinctrl_data *data = pinctrl_dev_get_drvdata(pctldev);

        return data->ngroups;
}

static const char *wmt_get_group_name(struct pinctrl_dev *pctldev,
                                      unsigned selector)
{
        struct wmt_pinctrl_data *data = pinctrl_dev_get_drvdata(pctldev);

        return data->groups[selector];
}

static int wmt_get_group_pins(struct pinctrl_dev *pctldev,
                              unsigned selector,
                              const unsigned **pins,
                              unsigned *num_pins)
{
        struct wmt_pinctrl_data *data = pinctrl_dev_get_drvdata(pctldev);

        *pins = &data->pins[selector].number;
        *num_pins = 1;

        return 0;
}

static int wmt_pctl_find_group_by_pin(struct wmt_pinctrl_data *data, u32 pin)
{
        int i;

        for (i = 0; i < data->npins; i++) {
                if (data->pins[i].number == pin)
                        return i;
        }

        return -EINVAL;
}

static int wmt_pctl_dt_node_to_map_func(struct wmt_pinctrl_data *data,
                                        struct device_node *np,
                                        u32 pin, u32 fnum,
                                        struct pinctrl_map **maps)
{
        int group;
        struct pinctrl_map *map = *maps;

        if (fnum >= ARRAY_SIZE(wmt_functions)) {
                dev_err(data->dev, "invalid wm,function %d\n", fnum);
                return -EINVAL;
        }

        group = wmt_pctl_find_group_by_pin(data, pin);
        if (group < 0) {
                dev_err(data->dev, "unable to match pin %d to group\n", pin);
                return group;
        }

        map->type = PIN_MAP_TYPE_MUX_GROUP;
        map->data.mux.group = data->groups[group];
        map->data.mux.function = wmt_functions[fnum];
        (*maps)++;

        return 0;
}

static int wmt_pctl_dt_node_to_map_pull(struct wmt_pinctrl_data *data,
                                        struct device_node *np,
                                        u32 pin, u32 pull,
                                        struct pinctrl_map **maps)
{
        int group;
        unsigned long *configs;
        struct pinctrl_map *map = *maps;

        if (pull > 2) {
                dev_err(data->dev, "invalid wm,pull %d\n", pull);
                return -EINVAL;
        }

        group = wmt_pctl_find_group_by_pin(data, pin);
        if (group < 0) {
                dev_err(data->dev, "unable to match pin %d to group\n", pin);
                return group;
        }

        configs = kzalloc_obj(*configs);
        if (!configs)
                return -ENOMEM;

        switch (pull) {
        case 0:
                configs[0] = PIN_CONFIG_BIAS_DISABLE;
                break;
        case 1:
                configs[0] = PIN_CONFIG_BIAS_PULL_DOWN;
                break;
        case 2:
                configs[0] = PIN_CONFIG_BIAS_PULL_UP;
                break;
        default:
                configs[0] = PIN_CONFIG_BIAS_DISABLE;
                dev_err(data->dev, "invalid pull state %d - disabling\n", pull);
        }

        map->type = PIN_MAP_TYPE_CONFIGS_PIN;
        map->data.configs.group_or_pin = data->groups[group];
        map->data.configs.configs = configs;
        map->data.configs.num_configs = 1;
        (*maps)++;

        return 0;
}

static void wmt_pctl_dt_free_map(struct pinctrl_dev *pctldev,
                                 struct pinctrl_map *maps,
                                 unsigned num_maps)
{
        int i;

        for (i = 0; i < num_maps; i++)
                if (maps[i].type == PIN_MAP_TYPE_CONFIGS_PIN)
                        kfree(maps[i].data.configs.configs);

        kfree(maps);
}

static int wmt_pctl_dt_node_to_map(struct pinctrl_dev *pctldev,
                                   struct device_node *np,
                                   struct pinctrl_map **map,
                                   unsigned *num_maps)
{
        struct pinctrl_map *maps, *cur_map;
        struct property *pins, *funcs, *pulls;
        u32 pin, func, pull;
        int num_pins, num_funcs, num_pulls, maps_per_pin;
        int i, err;
        struct wmt_pinctrl_data *data = pinctrl_dev_get_drvdata(pctldev);

        pins = of_find_property(np, "wm,pins", NULL);
        if (!pins) {
                dev_err(data->dev, "missing wmt,pins property\n");
                return -EINVAL;
        }

        funcs = of_find_property(np, "wm,function", NULL);
        pulls = of_find_property(np, "wm,pull", NULL);

        if (!funcs && !pulls) {
                dev_err(data->dev, "neither wm,function nor wm,pull specified\n");
                return -EINVAL;
        }

        /*
         * The following lines calculate how many values are defined for each
         * of the properties.
         */
        num_pins = pins->length / sizeof(u32);
        num_funcs = funcs ? (funcs->length / sizeof(u32)) : 0;
        num_pulls = pulls ? (pulls->length / sizeof(u32)) : 0;

        if (num_funcs > 1 && num_funcs != num_pins) {
                dev_err(data->dev, "wm,function must have 1 or %d entries\n",
                        num_pins);
                return -EINVAL;
        }

        if (num_pulls > 1 && num_pulls != num_pins) {
                dev_err(data->dev, "wm,pull must have 1 or %d entries\n",
                        num_pins);
                return -EINVAL;
        }

        maps_per_pin = 0;
        if (num_funcs)
                maps_per_pin++;
        if (num_pulls)
                maps_per_pin++;

        cur_map = maps = kzalloc_objs(*maps, num_pins * maps_per_pin);
        if (!maps)
                return -ENOMEM;

        for (i = 0; i < num_pins; i++) {
                err = of_property_read_u32_index(np, "wm,pins", i, &pin);
                if (err)
                        goto fail;

                if (pin >= (data->nbanks * 32)) {
                        dev_err(data->dev, "invalid wm,pins value\n");
                        err = -EINVAL;
                        goto fail;
                }

                if (num_funcs) {
                        err = of_property_read_u32_index(np, "wm,function",
                                                (num_funcs > 1 ? i : 0), &func);
                        if (err)
                                goto fail;

                        err = wmt_pctl_dt_node_to_map_func(data, np, pin, func,
                                                           &cur_map);
                        if (err)
                                goto fail;
                }

                if (num_pulls) {
                        err = of_property_read_u32_index(np, "wm,pull",
                                                (num_pulls > 1 ? i : 0), &pull);
                        if (err)
                                goto fail;

                        err = wmt_pctl_dt_node_to_map_pull(data, np, pin, pull,
                                                           &cur_map);
                        if (err)
                                goto fail;
                }
        }
        *map = maps;
        *num_maps = num_pins * maps_per_pin;
        return 0;

/*
 * The fail path removes any maps that have been allocated. The fail path is
 * only called from code after maps has been kzalloc'd. It is also safe to
 * pass 'num_pins * maps_per_pin' as the map count even though we probably
 * failed before all the mappings were read as all maps are allocated at once,
 * and configs are only allocated for .type = PIN_MAP_TYPE_CONFIGS_PIN - there
 * is no failpath where a config can be allocated without .type being set.
 */
fail:
        wmt_pctl_dt_free_map(pctldev, maps, num_pins * maps_per_pin);
        return err;
}

static const struct pinctrl_ops wmt_pctl_ops = {
        .get_groups_count = wmt_get_groups_count,
        .get_group_name = wmt_get_group_name,
        .get_group_pins = wmt_get_group_pins,
        .dt_node_to_map = wmt_pctl_dt_node_to_map,
        .dt_free_map = wmt_pctl_dt_free_map,
};

static int wmt_pinconf_get(struct pinctrl_dev *pctldev, unsigned pin,
                           unsigned long *config)
{
        return -ENOTSUPP;
}

static int wmt_pinconf_set(struct pinctrl_dev *pctldev, unsigned pin,
                           unsigned long *configs, unsigned num_configs)
{
        struct wmt_pinctrl_data *data = pinctrl_dev_get_drvdata(pctldev);
        enum pin_config_param param;
        u32 arg;
        u32 bank = WMT_BANK_FROM_PIN(pin);
        u32 bit = WMT_BIT_FROM_PIN(pin);
        u32 reg_pull_en = data->banks[bank].reg_pull_en;
        u32 reg_pull_cfg = data->banks[bank].reg_pull_cfg;
        int i;

        if ((reg_pull_en == NO_REG) || (reg_pull_cfg == NO_REG)) {
                dev_err(data->dev, "bias functions not supported on pin %d\n",
                        pin);
                return -EINVAL;
        }

        for (i = 0; i < num_configs; i++) {
                param = pinconf_to_config_param(configs[i]);
                arg = pinconf_to_config_argument(configs[i]);

                if ((param == PIN_CONFIG_BIAS_PULL_DOWN) ||
                    (param == PIN_CONFIG_BIAS_PULL_UP)) {
                        if (arg == 0)
                                param = PIN_CONFIG_BIAS_DISABLE;
                }

                switch (param) {
                case PIN_CONFIG_BIAS_DISABLE:
                        wmt_clearbits(data, reg_pull_en, BIT(bit));
                        break;
                case PIN_CONFIG_BIAS_PULL_DOWN:
                        wmt_clearbits(data, reg_pull_cfg, BIT(bit));
                        wmt_setbits(data, reg_pull_en, BIT(bit));
                        break;
                case PIN_CONFIG_BIAS_PULL_UP:
                        wmt_setbits(data, reg_pull_cfg, BIT(bit));
                        wmt_setbits(data, reg_pull_en, BIT(bit));
                        break;
                default:
                        dev_err(data->dev, "unknown pinconf param\n");
                        return -EINVAL;
                }
        } /* for each config */

        return 0;
}

static const struct pinconf_ops wmt_pinconf_ops = {
        .pin_config_get = wmt_pinconf_get,
        .pin_config_set = wmt_pinconf_set,
};

static struct pinctrl_desc wmt_desc = {
        .owner = THIS_MODULE,
        .name = "pinctrl-wmt",
        .pctlops = &wmt_pctl_ops,
        .pmxops = &wmt_pinmux_ops,
        .confops = &wmt_pinconf_ops,
};

static int wmt_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
{
        struct wmt_pinctrl_data *data = gpiochip_get_data(chip);
        u32 bank = WMT_BANK_FROM_PIN(offset);
        u32 bit = WMT_BIT_FROM_PIN(offset);
        u32 reg_dir = data->banks[bank].reg_dir;
        u32 val;

        val = readl_relaxed(data->base + reg_dir);
        if (val & BIT(bit))
                return GPIO_LINE_DIRECTION_OUT;

        return GPIO_LINE_DIRECTION_IN;
}

static int wmt_gpio_get_value(struct gpio_chip *chip, unsigned offset)
{
        struct wmt_pinctrl_data *data = gpiochip_get_data(chip);
        u32 bank = WMT_BANK_FROM_PIN(offset);
        u32 bit = WMT_BIT_FROM_PIN(offset);
        u32 reg_data_in = data->banks[bank].reg_data_in;

        if (reg_data_in == NO_REG) {
                dev_err(data->dev, "no data in register defined\n");
                return -EINVAL;
        }

        return !!(readl_relaxed(data->base + reg_data_in) & BIT(bit));
}

static int wmt_gpio_set_value(struct gpio_chip *chip, unsigned int offset,
                              int val)
{
        struct wmt_pinctrl_data *data = gpiochip_get_data(chip);
        u32 bank = WMT_BANK_FROM_PIN(offset);
        u32 bit = WMT_BIT_FROM_PIN(offset);
        u32 reg_data_out = data->banks[bank].reg_data_out;

        if (reg_data_out == NO_REG) {
                dev_err(data->dev, "no data out register defined\n");
                return -EINVAL;
        }

        if (val)
                wmt_setbits(data, reg_data_out, BIT(bit));
        else
                wmt_clearbits(data, reg_data_out, BIT(bit));

        return 0;
}

static int wmt_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
                                     int value)
{
        int ret;

        ret = wmt_gpio_set_value(chip, offset, value);
        if (ret)
                return ret;

        return pinctrl_gpio_direction_output(chip, offset);
}

static const struct gpio_chip wmt_gpio_chip = {
        .label = "gpio-wmt",
        .owner = THIS_MODULE,
        .request = gpiochip_generic_request,
        .free = gpiochip_generic_free,
        .get_direction = wmt_gpio_get_direction,
        .direction_input = pinctrl_gpio_direction_input,
        .direction_output = wmt_gpio_direction_output,
        .get = wmt_gpio_get_value,
        .set = wmt_gpio_set_value,
        .can_sleep = false,
};

int wmt_pinctrl_probe(struct platform_device *pdev,
                      struct wmt_pinctrl_data *data)
{
        int err;

        data->base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(data->base))
                return PTR_ERR(data->base);

        wmt_desc.pins = data->pins;
        wmt_desc.npins = data->npins;

        data->gpio_chip = wmt_gpio_chip;
        data->gpio_chip.parent = &pdev->dev;
        data->gpio_chip.ngpio = data->nbanks * 32;

        platform_set_drvdata(pdev, data);

        data->dev = &pdev->dev;

        data->pctl_dev = devm_pinctrl_register(&pdev->dev, &wmt_desc, data);
        if (IS_ERR(data->pctl_dev)) {
                dev_err(&pdev->dev, "Failed to register pinctrl\n");
                return PTR_ERR(data->pctl_dev);
        }

        err = gpiochip_add_data(&data->gpio_chip, data);
        if (err) {
                dev_err(&pdev->dev, "could not add GPIO chip\n");
                return err;
        }

        err = gpiochip_add_pin_range(&data->gpio_chip, dev_name(data->dev),
                                     0, 0, data->nbanks * 32);
        if (err)
                goto fail_range;

        dev_info(&pdev->dev, "Pin controller initialized\n");

        return 0;

fail_range:
        gpiochip_remove(&data->gpio_chip);
        return err;
}