--- /dev/null
+/*
+ * 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_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 = gpiochip_generic_request;
+ chip->free = gpiochip_generic_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 (IS_ERR(pmap->pctl)) {
+ dev_err(&pdev->dev, "pinctrl driver registration failed\n");
+ return PTR_ERR(pmap->pctl);
+ }
+
+ 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);
Code Review / kvmfornfv.git / blobdiff