root/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2016-2019, The Linux Foundation. All rights reserved.
 * Copyright (c) 2020 Linaro Ltd.
 */

#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/gpio/driver.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/seq_file.h>

#include <linux/pinctrl/pinconf-generic.h>
#include <linux/pinctrl/pinconf.h>
#include <linux/pinctrl/pinmux.h>

#include "../pinctrl-utils.h"

#include "pinctrl-lpass-lpi.h"

#define MAX_NR_GPIO             32
#define GPIO_FUNC               0
#define MAX_LPI_NUM_CLKS        2

struct lpi_pinctrl {
        struct device *dev;
        struct pinctrl_dev *ctrl;
        struct gpio_chip chip;
        struct pinctrl_desc desc;
        char __iomem *tlmm_base;
        char __iomem *slew_base;
        struct clk_bulk_data clks[MAX_LPI_NUM_CLKS];
        /* Protects from concurrent register updates */
        struct mutex lock;
        DECLARE_BITMAP(ever_gpio, MAX_NR_GPIO);
        const struct lpi_pinctrl_variant_data *data;
};

static int lpi_gpio_read(struct lpi_pinctrl *state, unsigned int pin,
                         unsigned int addr)
{
        u32 pin_offset;

        if (state->data->flags & LPI_FLAG_USE_PREDEFINED_PIN_OFFSET)
                pin_offset = state->data->groups[pin].pin_offset;
        else
                pin_offset = LPI_TLMM_REG_OFFSET * pin;

        return ioread32(state->tlmm_base + pin_offset + addr);
}

static int lpi_gpio_write(struct lpi_pinctrl *state, unsigned int pin,
                          unsigned int addr, unsigned int val)
{
        u32 pin_offset;

        if (state->data->flags & LPI_FLAG_USE_PREDEFINED_PIN_OFFSET)
                pin_offset = state->data->groups[pin].pin_offset;
        else
                pin_offset = LPI_TLMM_REG_OFFSET * pin;

        iowrite32(val, state->tlmm_base + pin_offset + addr);

        return 0;
}

static const struct pinctrl_ops lpi_gpio_pinctrl_ops = {
        .get_groups_count       = pinctrl_generic_get_group_count,
        .get_group_name         = pinctrl_generic_get_group_name,
        .get_group_pins         = pinctrl_generic_get_group_pins,
        .dt_node_to_map         = pinconf_generic_dt_node_to_map_group,
        .dt_free_map            = pinctrl_utils_free_map,
};

static int lpi_gpio_get_functions_count(struct pinctrl_dev *pctldev)
{
        struct lpi_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);

        return pctrl->data->nfunctions;
}

static const char *lpi_gpio_get_function_name(struct pinctrl_dev *pctldev,
                                              unsigned int function)
{
        struct lpi_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);

        return pctrl->data->functions[function].name;
}

static int lpi_gpio_get_function_groups(struct pinctrl_dev *pctldev,
                                        unsigned int function,
                                        const char *const **groups,
                                        unsigned *const num_qgroups)
{
        struct lpi_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);

        *groups = pctrl->data->functions[function].groups;
        *num_qgroups = pctrl->data->functions[function].ngroups;

        return 0;
}

static int lpi_gpio_set_mux(struct pinctrl_dev *pctldev, unsigned int function,
                            unsigned int group)
{
        struct lpi_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
        const struct lpi_pingroup *g = &pctrl->data->groups[group];
        u32 val;
        int i, pin = g->pin;

        for (i = 0; i < g->nfuncs; i++) {
                if (g->funcs[i] == function)
                        break;
        }

        if (WARN_ON(i == g->nfuncs))
                return -EINVAL;

        mutex_lock(&pctrl->lock);
        val = lpi_gpio_read(pctrl, pin, LPI_GPIO_CFG_REG);

        /*
         * If this is the first time muxing to GPIO and the direction is
         * output, make sure that we're not going to be glitching the pin
         * by reading the current state of the pin and setting it as the
         * output.
         */
        if (i == GPIO_FUNC && (val & LPI_GPIO_OE_MASK) &&
            !test_and_set_bit(group, pctrl->ever_gpio)) {
                u32 io_val = lpi_gpio_read(pctrl, group, LPI_GPIO_VALUE_REG);

                if (io_val & LPI_GPIO_VALUE_IN_MASK) {
                        if (!(io_val & LPI_GPIO_VALUE_OUT_MASK))
                                lpi_gpio_write(pctrl, group, LPI_GPIO_VALUE_REG,
                                               io_val | LPI_GPIO_VALUE_OUT_MASK);
                } else {
                        if (io_val & LPI_GPIO_VALUE_OUT_MASK)
                                lpi_gpio_write(pctrl, group, LPI_GPIO_VALUE_REG,
                                               io_val & ~LPI_GPIO_VALUE_OUT_MASK);
                }
        }

        u32p_replace_bits(&val, i, LPI_GPIO_FUNCTION_MASK);
        lpi_gpio_write(pctrl, pin, LPI_GPIO_CFG_REG, val);
        mutex_unlock(&pctrl->lock);

        return 0;
}

static const struct pinmux_ops lpi_gpio_pinmux_ops = {
        .get_functions_count    = lpi_gpio_get_functions_count,
        .get_function_name      = lpi_gpio_get_function_name,
        .get_function_groups    = lpi_gpio_get_function_groups,
        .set_mux                = lpi_gpio_set_mux,
};

static int lpi_config_get(struct pinctrl_dev *pctldev,
                          unsigned int pin, unsigned long *config)
{
        unsigned int param = pinconf_to_config_param(*config);
        struct lpi_pinctrl *state = dev_get_drvdata(pctldev->dev);
        unsigned int arg = 0;
        int is_out;
        int pull;
        u32 ctl_reg;

        ctl_reg = lpi_gpio_read(state, pin, LPI_GPIO_CFG_REG);
        is_out = ctl_reg & LPI_GPIO_OE_MASK;
        pull = FIELD_GET(LPI_GPIO_PULL_MASK, ctl_reg);

        switch (param) {
        case PIN_CONFIG_BIAS_DISABLE:
                if (pull == LPI_GPIO_BIAS_DISABLE)
                        arg = 1;
                break;
        case PIN_CONFIG_BIAS_PULL_DOWN:
                if (pull == LPI_GPIO_PULL_DOWN)
                        arg = 1;
                break;
        case PIN_CONFIG_BIAS_BUS_HOLD:
                if (pull == LPI_GPIO_KEEPER)
                        arg = 1;
                break;
        case PIN_CONFIG_BIAS_PULL_UP:
                if (pull == LPI_GPIO_PULL_UP)
                        arg = 1;
                break;
        case PIN_CONFIG_INPUT_ENABLE:
        case PIN_CONFIG_LEVEL:
                if (is_out)
                        arg = 1;
                break;
        default:
                return -EINVAL;
        }

        *config = pinconf_to_config_packed(param, arg);
        return 0;
}

static int lpi_config_set_slew_rate(struct lpi_pinctrl *pctrl,
                                    const struct lpi_pingroup *g,
                                    unsigned int group, unsigned int slew)
{
        unsigned long sval;
        void __iomem *reg;
        int slew_offset;

        if (slew > LPI_SLEW_RATE_MAX) {
                dev_err(pctrl->dev, "invalid slew rate %u for pin: %d\n",
                        slew, group);
                return -EINVAL;
        }

        slew_offset = g->slew_offset;
        if (slew_offset == LPI_NO_SLEW)
                return 0;

        if (pctrl->data->flags & LPI_FLAG_SLEW_RATE_SAME_REG)
                reg = pctrl->tlmm_base + LPI_TLMM_REG_OFFSET * group + LPI_GPIO_CFG_REG;
        else
                reg = pctrl->slew_base + LPI_SLEW_RATE_CTL_REG;

        mutex_lock(&pctrl->lock);

        sval = ioread32(reg);
        sval &= ~(LPI_SLEW_RATE_MASK << slew_offset);
        sval |= slew << slew_offset;
        iowrite32(sval, reg);

        mutex_unlock(&pctrl->lock);

        return 0;
}

static int lpi_config_set(struct pinctrl_dev *pctldev, unsigned int group,
                          unsigned long *configs, unsigned int nconfs)
{
        struct lpi_pinctrl *pctrl = dev_get_drvdata(pctldev->dev);
        unsigned int param, arg, pullup = LPI_GPIO_BIAS_DISABLE, strength = 2;
        bool value, output_enabled = false;
        const struct lpi_pingroup *g;
        int i, ret;
        u32 val;

        g = &pctrl->data->groups[group];
        for (i = 0; i < nconfs; i++) {
                param = pinconf_to_config_param(configs[i]);
                arg = pinconf_to_config_argument(configs[i]);

                switch (param) {
                case PIN_CONFIG_BIAS_DISABLE:
                        pullup = LPI_GPIO_BIAS_DISABLE;
                        break;
                case PIN_CONFIG_BIAS_PULL_DOWN:
                        pullup = LPI_GPIO_PULL_DOWN;
                        break;
                case PIN_CONFIG_BIAS_BUS_HOLD:
                        pullup = LPI_GPIO_KEEPER;
                        break;
                case PIN_CONFIG_BIAS_PULL_UP:
                        pullup = LPI_GPIO_PULL_UP;
                        break;
                case PIN_CONFIG_INPUT_ENABLE:
                        output_enabled = false;
                        break;
                case PIN_CONFIG_LEVEL:
                        output_enabled = true;
                        value = arg;
                        break;
                case PIN_CONFIG_DRIVE_STRENGTH:
                        strength = arg;
                        break;
                case PIN_CONFIG_SLEW_RATE:
                        ret = lpi_config_set_slew_rate(pctrl, g, group, arg);
                        if (ret)
                                return ret;
                        break;
                default:
                        return -EINVAL;
                }
        }

        /*
         * As per Hardware Programming Guide, when configuring pin as output,
         * set the pin value before setting output-enable (OE).
         */
        if (output_enabled) {
                val = u32_encode_bits(value ? 1 : 0, LPI_GPIO_VALUE_OUT_MASK);
                lpi_gpio_write(pctrl, group, LPI_GPIO_VALUE_REG, val);
        }

        mutex_lock(&pctrl->lock);
        val = lpi_gpio_read(pctrl, group, LPI_GPIO_CFG_REG);

        u32p_replace_bits(&val, pullup, LPI_GPIO_PULL_MASK);
        u32p_replace_bits(&val, LPI_GPIO_DS_TO_VAL(strength),
                          LPI_GPIO_OUT_STRENGTH_MASK);
        u32p_replace_bits(&val, output_enabled, LPI_GPIO_OE_MASK);

        lpi_gpio_write(pctrl, group, LPI_GPIO_CFG_REG, val);
        mutex_unlock(&pctrl->lock);

        return 0;
}

static const struct pinconf_ops lpi_gpio_pinconf_ops = {
        .is_generic                     = true,
        .pin_config_group_get           = lpi_config_get,
        .pin_config_group_set           = lpi_config_set,
};

static int lpi_gpio_get_direction(struct gpio_chip *chip, unsigned int pin)
{
        unsigned long config = pinconf_to_config_packed(PIN_CONFIG_LEVEL, 0);
        struct lpi_pinctrl *state = gpiochip_get_data(chip);
        unsigned long arg;
        int ret;

        ret = lpi_config_get(state->ctrl, pin, &config);
        if (ret)
                return ret;

        arg = pinconf_to_config_argument(config);

        return arg ? GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
}

static int lpi_gpio_direction_input(struct gpio_chip *chip, unsigned int pin)
{
        struct lpi_pinctrl *state = gpiochip_get_data(chip);
        unsigned long config;

        config = pinconf_to_config_packed(PIN_CONFIG_INPUT_ENABLE, 1);

        return lpi_config_set(state->ctrl, pin, &config, 1);
}

static int lpi_gpio_direction_output(struct gpio_chip *chip,
                                     unsigned int pin, int val)
{
        struct lpi_pinctrl *state = gpiochip_get_data(chip);
        unsigned long config;

        config = pinconf_to_config_packed(PIN_CONFIG_LEVEL, val);

        return lpi_config_set(state->ctrl, pin, &config, 1);
}

static int lpi_gpio_get(struct gpio_chip *chip, unsigned int pin)
{
        struct lpi_pinctrl *state = gpiochip_get_data(chip);

        return lpi_gpio_read(state, pin, LPI_GPIO_VALUE_REG) &
                LPI_GPIO_VALUE_IN_MASK;
}

static int lpi_gpio_set(struct gpio_chip *chip, unsigned int pin, int value)
{
        struct lpi_pinctrl *state = gpiochip_get_data(chip);
        unsigned long config;

        config = pinconf_to_config_packed(PIN_CONFIG_LEVEL, value);

        return lpi_config_set(state->ctrl, pin, &config, 1);
}

#ifdef CONFIG_DEBUG_FS

static unsigned int lpi_regval_to_drive(u32 val)
{
        return (val + 1) * 2;
}

static void lpi_gpio_dbg_show_one(struct seq_file *s,
                                  struct pinctrl_dev *pctldev,
                                  struct gpio_chip *chip,
                                  unsigned int offset,
                                  unsigned int gpio)
{
        struct lpi_pinctrl *state = gpiochip_get_data(chip);
        struct pinctrl_pin_desc pindesc;
        unsigned int func;
        int is_out;
        int drive;
        int pull;
        u32 ctl_reg;

        static const char * const pulls[] = {
                "no pull",
                "pull down",
                "keeper",
                "pull up"
        };

        pctldev = pctldev ? : state->ctrl;
        pindesc = pctldev->desc->pins[offset];
        ctl_reg = lpi_gpio_read(state, offset, LPI_GPIO_CFG_REG);
        is_out = ctl_reg & LPI_GPIO_OE_MASK;

        func = FIELD_GET(LPI_GPIO_FUNCTION_MASK, ctl_reg);
        drive = FIELD_GET(LPI_GPIO_OUT_STRENGTH_MASK, ctl_reg);
        pull = FIELD_GET(LPI_GPIO_PULL_MASK, ctl_reg);

        seq_printf(s, " %-8s: %-3s %d", pindesc.name, is_out ? "out" : "in", func);
        seq_printf(s, " %dmA", lpi_regval_to_drive(drive));
        seq_printf(s, " %s", pulls[pull]);
}

static void lpi_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
{
        unsigned int gpio = chip->base;
        unsigned int i;

        for (i = 0; i < chip->ngpio; i++, gpio++) {
                lpi_gpio_dbg_show_one(s, NULL, chip, i, gpio);
                seq_puts(s, "\n");
        }
}

#else
#define lpi_gpio_dbg_show NULL
#endif

static const struct gpio_chip lpi_gpio_template = {
        .get_direction          = lpi_gpio_get_direction,
        .direction_input        = lpi_gpio_direction_input,
        .direction_output       = lpi_gpio_direction_output,
        .get                    = lpi_gpio_get,
        .set                    = lpi_gpio_set,
        .request                = gpiochip_generic_request,
        .free                   = gpiochip_generic_free,
        .dbg_show               = lpi_gpio_dbg_show,
};

static int lpi_build_pin_desc_groups(struct lpi_pinctrl *pctrl)
{
        int i, ret;

        for (i = 0; i < pctrl->data->npins; i++) {
                const struct pinctrl_pin_desc *pin_info = pctrl->desc.pins + i;

                ret = pinctrl_generic_add_group(pctrl->ctrl, pin_info->name,
                                                  (int *)&pin_info->number, 1, NULL);
                if (ret < 0)
                        goto err_pinctrl;
        }

        return 0;

err_pinctrl:
        for (; i > 0; i--)
                pinctrl_generic_remove_group(pctrl->ctrl, i - 1);

        return ret;
}

int lpi_pinctrl_probe(struct platform_device *pdev)
{
        const struct lpi_pinctrl_variant_data *data;
        struct device *dev = &pdev->dev;
        struct lpi_pinctrl *pctrl;
        int ret;

        pctrl = devm_kzalloc(dev, sizeof(*pctrl), GFP_KERNEL);
        if (!pctrl)
                return -ENOMEM;

        platform_set_drvdata(pdev, pctrl);

        data = of_device_get_match_data(dev);
        if (!data)
                return -EINVAL;

        if (WARN_ON(data->npins > MAX_NR_GPIO))
                return -EINVAL;

        pctrl->data = data;
        pctrl->dev = &pdev->dev;

        pctrl->clks[0].id = "core";
        pctrl->clks[1].id = "audio";

        pctrl->tlmm_base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(pctrl->tlmm_base))
                return dev_err_probe(dev, PTR_ERR(pctrl->tlmm_base),
                                     "TLMM resource not provided\n");

        if (!(data->flags & LPI_FLAG_SLEW_RATE_SAME_REG)) {
                pctrl->slew_base = devm_platform_ioremap_resource(pdev, 1);
                if (IS_ERR(pctrl->slew_base))
                        return dev_err_probe(dev, PTR_ERR(pctrl->slew_base),
                                             "Slew resource not provided\n");
        }

        ret = devm_clk_bulk_get_optional(dev, MAX_LPI_NUM_CLKS, pctrl->clks);
        if (ret)
                return ret;

        ret = clk_bulk_prepare_enable(MAX_LPI_NUM_CLKS, pctrl->clks);
        if (ret)
                return dev_err_probe(dev, ret, "Can't enable clocks\n");

        pctrl->desc.pctlops = &lpi_gpio_pinctrl_ops;
        pctrl->desc.pmxops = &lpi_gpio_pinmux_ops;
        pctrl->desc.confops = &lpi_gpio_pinconf_ops;
        pctrl->desc.owner = THIS_MODULE;
        pctrl->desc.name = dev_name(dev);
        pctrl->desc.pins = data->pins;
        pctrl->desc.npins = data->npins;
        pctrl->chip = lpi_gpio_template;
        pctrl->chip.parent = dev;
        pctrl->chip.base = -1;
        pctrl->chip.ngpio = data->npins;
        pctrl->chip.label = dev_name(dev);
        pctrl->chip.can_sleep = true;

        mutex_init(&pctrl->lock);

        pctrl->ctrl = devm_pinctrl_register(dev, &pctrl->desc, pctrl);
        if (IS_ERR(pctrl->ctrl)) {
                ret = PTR_ERR(pctrl->ctrl);
                dev_err(dev, "failed to add pin controller\n");
                goto err_pinctrl;
        }

        ret = lpi_build_pin_desc_groups(pctrl);
        if (ret)
                goto err_pinctrl;

        ret = devm_gpiochip_add_data(dev, &pctrl->chip, pctrl);
        if (ret) {
                dev_err(pctrl->dev, "can't add gpio chip\n");
                goto err_pinctrl;
        }

        return 0;

err_pinctrl:
        mutex_destroy(&pctrl->lock);
        clk_bulk_disable_unprepare(MAX_LPI_NUM_CLKS, pctrl->clks);

        return ret;
}
EXPORT_SYMBOL_GPL(lpi_pinctrl_probe);

void lpi_pinctrl_remove(struct platform_device *pdev)
{
        struct lpi_pinctrl *pctrl = platform_get_drvdata(pdev);
        int i;

        mutex_destroy(&pctrl->lock);
        clk_bulk_disable_unprepare(MAX_LPI_NUM_CLKS, pctrl->clks);

        for (i = 0; i < pctrl->data->npins; i++)
                pinctrl_generic_remove_group(pctrl->ctrl, i);
}
EXPORT_SYMBOL_GPL(lpi_pinctrl_remove);

MODULE_DESCRIPTION("QTI LPI GPIO pin control driver");
MODULE_LICENSE("GPL");