--- /dev/null
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * License Terms: GNU General Public License, version 2
+ * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/mfd/stmpe.h>
+#include <linux/seq_file.h>
+
+/*
+ * These registers are modified under the irq bus lock and cached to avoid
+ * unnecessary writes in bus_sync_unlock.
+ */
+enum { REG_RE, REG_FE, REG_IE };
+
+#define CACHE_NR_REGS 3
+/* No variant has more than 24 GPIOs */
+#define CACHE_NR_BANKS (24 / 8)
+
+struct stmpe_gpio {
+ struct gpio_chip chip;
+ struct stmpe *stmpe;
+ struct device *dev;
+ struct mutex irq_lock;
+ u32 norequest_mask;
+ /* Caches of interrupt control registers for bus_lock */
+ u8 regs[CACHE_NR_REGS][CACHE_NR_BANKS];
+ u8 oldregs[CACHE_NR_REGS][CACHE_NR_BANKS];
+};
+
+static inline struct stmpe_gpio *to_stmpe_gpio(struct gpio_chip *chip)
+{
+ return container_of(chip, struct stmpe_gpio, chip);
+}
+
+static int stmpe_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(chip);
+ struct stmpe *stmpe = stmpe_gpio->stmpe;
+ u8 reg = stmpe->regs[STMPE_IDX_GPMR_LSB] - (offset / 8);
+ u8 mask = 1 << (offset % 8);
+ int ret;
+
+ ret = stmpe_reg_read(stmpe, reg);
+ if (ret < 0)
+ return ret;
+
+ return !!(ret & mask);
+}
+
+static void stmpe_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
+{
+ struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(chip);
+ struct stmpe *stmpe = stmpe_gpio->stmpe;
+ int which = val ? STMPE_IDX_GPSR_LSB : STMPE_IDX_GPCR_LSB;
+ u8 reg = stmpe->regs[which] - (offset / 8);
+ u8 mask = 1 << (offset % 8);
+
+ /*
+ * Some variants have single register for gpio set/clear functionality.
+ * For them we need to write 0 to clear and 1 to set.
+ */
+ if (stmpe->regs[STMPE_IDX_GPSR_LSB] == stmpe->regs[STMPE_IDX_GPCR_LSB])
+ stmpe_set_bits(stmpe, reg, mask, val ? mask : 0);
+ else
+ stmpe_reg_write(stmpe, reg, mask);
+}
+
+static int stmpe_gpio_direction_output(struct gpio_chip *chip,
+ unsigned offset, int val)
+{
+ struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(chip);
+ struct stmpe *stmpe = stmpe_gpio->stmpe;
+ u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB] - (offset / 8);
+ u8 mask = 1 << (offset % 8);
+
+ stmpe_gpio_set(chip, offset, val);
+
+ return stmpe_set_bits(stmpe, reg, mask, mask);
+}
+
+static int stmpe_gpio_direction_input(struct gpio_chip *chip,
+ unsigned offset)
+{
+ struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(chip);
+ struct stmpe *stmpe = stmpe_gpio->stmpe;
+ u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB] - (offset / 8);
+ u8 mask = 1 << (offset % 8);
+
+ return stmpe_set_bits(stmpe, reg, mask, 0);
+}
+
+static int stmpe_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+ struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(chip);
+ struct stmpe *stmpe = stmpe_gpio->stmpe;
+
+ if (stmpe_gpio->norequest_mask & (1 << offset))
+ return -EINVAL;
+
+ return stmpe_set_altfunc(stmpe, 1 << offset, STMPE_BLOCK_GPIO);
+}
+
+static struct gpio_chip template_chip = {
+ .label = "stmpe",
+ .owner = THIS_MODULE,
+ .direction_input = stmpe_gpio_direction_input,
+ .get = stmpe_gpio_get,
+ .direction_output = stmpe_gpio_direction_output,
+ .set = stmpe_gpio_set,
+ .request = stmpe_gpio_request,
+ .can_sleep = true,
+};
+
+static int stmpe_gpio_irq_set_type(struct irq_data *d, unsigned int type)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(gc);
+ int offset = d->hwirq;
+ int regoffset = offset / 8;
+ int mask = 1 << (offset % 8);
+
+ if (type & IRQ_TYPE_LEVEL_LOW || type & IRQ_TYPE_LEVEL_HIGH)
+ return -EINVAL;
+
+ /* STMPE801 doesn't have RE and FE registers */
+ if (stmpe_gpio->stmpe->partnum == STMPE801)
+ return 0;
+
+ if (type & IRQ_TYPE_EDGE_RISING)
+ stmpe_gpio->regs[REG_RE][regoffset] |= mask;
+ else
+ stmpe_gpio->regs[REG_RE][regoffset] &= ~mask;
+
+ if (type & IRQ_TYPE_EDGE_FALLING)
+ stmpe_gpio->regs[REG_FE][regoffset] |= mask;
+ else
+ stmpe_gpio->regs[REG_FE][regoffset] &= ~mask;
+
+ return 0;
+}
+
+static void stmpe_gpio_irq_lock(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(gc);
+
+ mutex_lock(&stmpe_gpio->irq_lock);
+}
+
+static void stmpe_gpio_irq_sync_unlock(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(gc);
+ struct stmpe *stmpe = stmpe_gpio->stmpe;
+ int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8);
+ static const u8 regmap[] = {
+ [REG_RE] = STMPE_IDX_GPRER_LSB,
+ [REG_FE] = STMPE_IDX_GPFER_LSB,
+ [REG_IE] = STMPE_IDX_IEGPIOR_LSB,
+ };
+ int i, j;
+
+ for (i = 0; i < CACHE_NR_REGS; i++) {
+ /* STMPE801 doesn't have RE and FE registers */
+ if ((stmpe->partnum == STMPE801) &&
+ (i != REG_IE))
+ continue;
+
+ for (j = 0; j < num_banks; j++) {
+ u8 old = stmpe_gpio->oldregs[i][j];
+ u8 new = stmpe_gpio->regs[i][j];
+
+ if (new == old)
+ continue;
+
+ stmpe_gpio->oldregs[i][j] = new;
+ stmpe_reg_write(stmpe, stmpe->regs[regmap[i]] - j, new);
+ }
+ }
+
+ mutex_unlock(&stmpe_gpio->irq_lock);
+}
+
+static void stmpe_gpio_irq_mask(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(gc);
+ int offset = d->hwirq;
+ int regoffset = offset / 8;
+ int mask = 1 << (offset % 8);
+
+ stmpe_gpio->regs[REG_IE][regoffset] &= ~mask;
+}
+
+static void stmpe_gpio_irq_unmask(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(gc);
+ int offset = d->hwirq;
+ int regoffset = offset / 8;
+ int mask = 1 << (offset % 8);
+
+ stmpe_gpio->regs[REG_IE][regoffset] |= mask;
+}
+
+static void stmpe_dbg_show_one(struct seq_file *s,
+ struct gpio_chip *gc,
+ unsigned offset, unsigned gpio)
+{
+ struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(gc);
+ struct stmpe *stmpe = stmpe_gpio->stmpe;
+ const char *label = gpiochip_is_requested(gc, offset);
+ int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8);
+ bool val = !!stmpe_gpio_get(gc, offset);
+ u8 dir_reg = stmpe->regs[STMPE_IDX_GPDR_LSB] - (offset / 8);
+ u8 mask = 1 << (offset % 8);
+ int ret;
+ u8 dir;
+
+ ret = stmpe_reg_read(stmpe, dir_reg);
+ if (ret < 0)
+ return;
+ dir = !!(ret & mask);
+
+ if (dir) {
+ seq_printf(s, " gpio-%-3d (%-20.20s) out %s",
+ gpio, label ?: "(none)",
+ val ? "hi" : "lo");
+ } else {
+ u8 edge_det_reg = stmpe->regs[STMPE_IDX_GPEDR_MSB] + num_banks - 1 - (offset / 8);
+ u8 rise_reg = stmpe->regs[STMPE_IDX_GPRER_LSB] - (offset / 8);
+ u8 fall_reg = stmpe->regs[STMPE_IDX_GPFER_LSB] - (offset / 8);
+ u8 irqen_reg = stmpe->regs[STMPE_IDX_IEGPIOR_LSB] - (offset / 8);
+ bool edge_det;
+ bool rise;
+ bool fall;
+ bool irqen;
+
+ ret = stmpe_reg_read(stmpe, edge_det_reg);
+ if (ret < 0)
+ return;
+ edge_det = !!(ret & mask);
+ ret = stmpe_reg_read(stmpe, rise_reg);
+ if (ret < 0)
+ return;
+ rise = !!(ret & mask);
+ ret = stmpe_reg_read(stmpe, fall_reg);
+ if (ret < 0)
+ return;
+ fall = !!(ret & mask);
+ ret = stmpe_reg_read(stmpe, irqen_reg);
+ if (ret < 0)
+ return;
+ irqen = !!(ret & mask);
+
+ seq_printf(s, " gpio-%-3d (%-20.20s) in %s %s %s%s%s",
+ gpio, label ?: "(none)",
+ val ? "hi" : "lo",
+ edge_det ? "edge-asserted" : "edge-inactive",
+ irqen ? "IRQ-enabled" : "",
+ rise ? " rising-edge-detection" : "",
+ fall ? " falling-edge-detection" : "");
+ }
+}
+
+static void stmpe_dbg_show(struct seq_file *s, struct gpio_chip *gc)
+{
+ unsigned i;
+ unsigned gpio = gc->base;
+
+ for (i = 0; i < gc->ngpio; i++, gpio++) {
+ stmpe_dbg_show_one(s, gc, i, gpio);
+ seq_printf(s, "\n");
+ }
+}
+
+static struct irq_chip stmpe_gpio_irq_chip = {
+ .name = "stmpe-gpio",
+ .irq_bus_lock = stmpe_gpio_irq_lock,
+ .irq_bus_sync_unlock = stmpe_gpio_irq_sync_unlock,
+ .irq_mask = stmpe_gpio_irq_mask,
+ .irq_unmask = stmpe_gpio_irq_unmask,
+ .irq_set_type = stmpe_gpio_irq_set_type,
+};
+
+static irqreturn_t stmpe_gpio_irq(int irq, void *dev)
+{
+ struct stmpe_gpio *stmpe_gpio = dev;
+ struct stmpe *stmpe = stmpe_gpio->stmpe;
+ u8 statmsbreg = stmpe->regs[STMPE_IDX_ISGPIOR_MSB];
+ int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8);
+ u8 status[num_banks];
+ int ret;
+ int i;
+
+ ret = stmpe_block_read(stmpe, statmsbreg, num_banks, status);
+ if (ret < 0)
+ return IRQ_NONE;
+
+ for (i = 0; i < num_banks; i++) {
+ int bank = num_banks - i - 1;
+ unsigned int enabled = stmpe_gpio->regs[REG_IE][bank];
+ unsigned int stat = status[i];
+
+ stat &= enabled;
+ if (!stat)
+ continue;
+
+ while (stat) {
+ int bit = __ffs(stat);
+ int line = bank * 8 + bit;
+ int child_irq = irq_find_mapping(stmpe_gpio->chip.irqdomain,
+ line);
+
+ handle_nested_irq(child_irq);
+ stat &= ~(1 << bit);
+ }
+
+ stmpe_reg_write(stmpe, statmsbreg + i, status[i]);
+
+ /* Edge detect register is not present on 801 */
+ if (stmpe->partnum != STMPE801)
+ stmpe_reg_write(stmpe, stmpe->regs[STMPE_IDX_GPEDR_MSB]
+ + i, status[i]);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int stmpe_gpio_probe(struct platform_device *pdev)
+{
+ struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
+ struct device_node *np = pdev->dev.of_node;
+ struct stmpe_gpio *stmpe_gpio;
+ int ret;
+ int irq = 0;
+
+ irq = platform_get_irq(pdev, 0);
+
+ stmpe_gpio = kzalloc(sizeof(struct stmpe_gpio), GFP_KERNEL);
+ if (!stmpe_gpio)
+ return -ENOMEM;
+
+ mutex_init(&stmpe_gpio->irq_lock);
+
+ stmpe_gpio->dev = &pdev->dev;
+ stmpe_gpio->stmpe = stmpe;
+ stmpe_gpio->chip = template_chip;
+ stmpe_gpio->chip.ngpio = stmpe->num_gpios;
+ stmpe_gpio->chip.dev = &pdev->dev;
+ stmpe_gpio->chip.of_node = np;
+ stmpe_gpio->chip.base = -1;
+
+ if (IS_ENABLED(CONFIG_DEBUG_FS))
+ stmpe_gpio->chip.dbg_show = stmpe_dbg_show;
+
+ of_property_read_u32(np, "st,norequest-mask",
+ &stmpe_gpio->norequest_mask);
+
+ if (irq < 0)
+ dev_info(&pdev->dev,
+ "device configured in no-irq mode: "
+ "irqs are not available\n");
+
+ ret = stmpe_enable(stmpe, STMPE_BLOCK_GPIO);
+ if (ret)
+ goto out_free;
+
+ ret = gpiochip_add(&stmpe_gpio->chip);
+ if (ret) {
+ dev_err(&pdev->dev, "unable to add gpiochip: %d\n", ret);
+ goto out_disable;
+ }
+
+ if (irq > 0) {
+ ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+ stmpe_gpio_irq, IRQF_ONESHOT,
+ "stmpe-gpio", stmpe_gpio);
+ if (ret) {
+ dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
+ goto out_disable;
+ }
+ ret = gpiochip_irqchip_add(&stmpe_gpio->chip,
+ &stmpe_gpio_irq_chip,
+ 0,
+ handle_simple_irq,
+ IRQ_TYPE_NONE);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "could not connect irqchip to gpiochip\n");
+ goto out_disable;
+ }
+
+ gpiochip_set_chained_irqchip(&stmpe_gpio->chip,
+ &stmpe_gpio_irq_chip,
+ irq,
+ NULL);
+ }
+
+ platform_set_drvdata(pdev, stmpe_gpio);
+
+ return 0;
+
+out_disable:
+ stmpe_disable(stmpe, STMPE_BLOCK_GPIO);
+ gpiochip_remove(&stmpe_gpio->chip);
+out_free:
+ kfree(stmpe_gpio);
+ return ret;
+}
+
+static int stmpe_gpio_remove(struct platform_device *pdev)
+{
+ struct stmpe_gpio *stmpe_gpio = platform_get_drvdata(pdev);
+ struct stmpe *stmpe = stmpe_gpio->stmpe;
+
+ gpiochip_remove(&stmpe_gpio->chip);
+ stmpe_disable(stmpe, STMPE_BLOCK_GPIO);
+ kfree(stmpe_gpio);
+
+ return 0;
+}
+
+static struct platform_driver stmpe_gpio_driver = {
+ .driver.name = "stmpe-gpio",
+ .driver.owner = THIS_MODULE,
+ .probe = stmpe_gpio_probe,
+ .remove = stmpe_gpio_remove,
+};
+
+static int __init stmpe_gpio_init(void)
+{
+ return platform_driver_register(&stmpe_gpio_driver);
+}
+subsys_initcall(stmpe_gpio_init);
+
+static void __exit stmpe_gpio_exit(void)
+{
+ platform_driver_unregister(&stmpe_gpio_driver);
+}
+module_exit(stmpe_gpio_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("STMPExxxx GPIO driver");
+MODULE_AUTHOR("Rabin Vincent <rabin.vincent@stericsson.com>");
Code Review / kvmfornfv.git / blobdiff