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218 lines
5.6 KiB
218 lines
5.6 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* GPIO driver for EXAR XRA1403 16-bit GPIO expander |
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* |
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* Copyright (c) 2017, General Electric Company |
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*/ |
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#include <linux/bitops.h> |
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#include <linux/gpio/driver.h> |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/mutex.h> |
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#include <linux/of_device.h> |
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#include <linux/of_gpio.h> |
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#include <linux/seq_file.h> |
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#include <linux/spi/spi.h> |
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#include <linux/regmap.h> |
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/* XRA1403 registers */ |
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#define XRA_GSR 0x00 /* GPIO State */ |
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#define XRA_OCR 0x02 /* Output Control */ |
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#define XRA_PIR 0x04 /* Input Polarity Inversion */ |
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#define XRA_GCR 0x06 /* GPIO Configuration */ |
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#define XRA_PUR 0x08 /* Input Internal Pull-up Resistor Enable/Disable */ |
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#define XRA_IER 0x0A /* Input Interrupt Enable */ |
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#define XRA_TSCR 0x0C /* Output Three-State Control */ |
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#define XRA_ISR 0x0E /* Input Interrupt Status */ |
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#define XRA_REIR 0x10 /* Input Rising Edge Interrupt Enable */ |
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#define XRA_FEIR 0x12 /* Input Falling Edge Interrupt Enable */ |
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#define XRA_IFR 0x14 /* Input Filter Enable/Disable */ |
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#define XRA_LAST 0x15 /* Bounds */ |
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struct xra1403 { |
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struct gpio_chip chip; |
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struct regmap *regmap; |
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}; |
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static const struct regmap_config xra1403_regmap_cfg = { |
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.reg_bits = 7, |
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.pad_bits = 1, |
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.val_bits = 8, |
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.max_register = XRA_LAST, |
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}; |
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static unsigned int to_reg(unsigned int reg, unsigned int offset) |
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{ |
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return reg + (offset > 7); |
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} |
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static int xra1403_direction_input(struct gpio_chip *chip, unsigned int offset) |
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{ |
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struct xra1403 *xra = gpiochip_get_data(chip); |
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return regmap_update_bits(xra->regmap, to_reg(XRA_GCR, offset), |
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BIT(offset % 8), BIT(offset % 8)); |
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} |
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static int xra1403_direction_output(struct gpio_chip *chip, unsigned int offset, |
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int value) |
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{ |
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int ret; |
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struct xra1403 *xra = gpiochip_get_data(chip); |
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ret = regmap_update_bits(xra->regmap, to_reg(XRA_GCR, offset), |
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BIT(offset % 8), 0); |
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if (ret) |
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return ret; |
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ret = regmap_update_bits(xra->regmap, to_reg(XRA_OCR, offset), |
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BIT(offset % 8), value ? BIT(offset % 8) : 0); |
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return ret; |
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} |
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static int xra1403_get_direction(struct gpio_chip *chip, unsigned int offset) |
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{ |
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int ret; |
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unsigned int val; |
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struct xra1403 *xra = gpiochip_get_data(chip); |
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ret = regmap_read(xra->regmap, to_reg(XRA_GCR, offset), &val); |
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if (ret) |
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return ret; |
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if (val & BIT(offset % 8)) |
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return GPIO_LINE_DIRECTION_IN; |
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return GPIO_LINE_DIRECTION_OUT; |
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} |
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static int xra1403_get(struct gpio_chip *chip, unsigned int offset) |
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{ |
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int ret; |
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unsigned int val; |
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struct xra1403 *xra = gpiochip_get_data(chip); |
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ret = regmap_read(xra->regmap, to_reg(XRA_GSR, offset), &val); |
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if (ret) |
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return ret; |
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return !!(val & BIT(offset % 8)); |
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} |
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static void xra1403_set(struct gpio_chip *chip, unsigned int offset, int value) |
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{ |
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int ret; |
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struct xra1403 *xra = gpiochip_get_data(chip); |
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ret = regmap_update_bits(xra->regmap, to_reg(XRA_OCR, offset), |
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BIT(offset % 8), value ? BIT(offset % 8) : 0); |
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if (ret) |
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dev_err(chip->parent, "Failed to set pin: %d, ret: %d\n", |
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offset, ret); |
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} |
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#ifdef CONFIG_DEBUG_FS |
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static void xra1403_dbg_show(struct seq_file *s, struct gpio_chip *chip) |
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{ |
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int reg; |
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struct xra1403 *xra = gpiochip_get_data(chip); |
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int value[XRA_LAST]; |
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int i; |
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const char *label; |
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unsigned int gcr; |
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unsigned int gsr; |
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seq_puts(s, "xra reg:"); |
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for (reg = 0; reg <= XRA_LAST; reg++) |
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seq_printf(s, " %2.2x", reg); |
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seq_puts(s, "\n value:"); |
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for (reg = 0; reg < XRA_LAST; reg++) { |
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regmap_read(xra->regmap, reg, &value[reg]); |
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seq_printf(s, " %2.2x", value[reg]); |
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} |
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seq_puts(s, "\n"); |
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gcr = value[XRA_GCR + 1] << 8 | value[XRA_GCR]; |
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gsr = value[XRA_GSR + 1] << 8 | value[XRA_GSR]; |
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for_each_requested_gpio(chip, i, label) { |
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seq_printf(s, " gpio-%-3d (%-12s) %s %s\n", |
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chip->base + i, label, |
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(gcr & BIT(i)) ? "in" : "out", |
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(gsr & BIT(i)) ? "hi" : "lo"); |
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} |
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} |
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#else |
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#define xra1403_dbg_show NULL |
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#endif |
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static int xra1403_probe(struct spi_device *spi) |
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{ |
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struct xra1403 *xra; |
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struct gpio_desc *reset_gpio; |
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int ret; |
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xra = devm_kzalloc(&spi->dev, sizeof(*xra), GFP_KERNEL); |
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if (!xra) |
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return -ENOMEM; |
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/* bring the chip out of reset if reset pin is provided*/ |
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reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset", GPIOD_OUT_LOW); |
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if (IS_ERR(reset_gpio)) |
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dev_warn(&spi->dev, "Could not get reset-gpios\n"); |
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xra->chip.direction_input = xra1403_direction_input; |
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xra->chip.direction_output = xra1403_direction_output; |
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xra->chip.get_direction = xra1403_get_direction; |
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xra->chip.get = xra1403_get; |
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xra->chip.set = xra1403_set; |
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xra->chip.dbg_show = xra1403_dbg_show; |
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xra->chip.ngpio = 16; |
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xra->chip.label = "xra1403"; |
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xra->chip.base = -1; |
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xra->chip.can_sleep = true; |
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xra->chip.parent = &spi->dev; |
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xra->chip.owner = THIS_MODULE; |
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xra->regmap = devm_regmap_init_spi(spi, &xra1403_regmap_cfg); |
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if (IS_ERR(xra->regmap)) { |
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ret = PTR_ERR(xra->regmap); |
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dev_err(&spi->dev, "Failed to allocate regmap: %d\n", ret); |
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return ret; |
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} |
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return devm_gpiochip_add_data(&spi->dev, &xra->chip, xra); |
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} |
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static const struct spi_device_id xra1403_ids[] = { |
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{ "xra1403" }, |
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{}, |
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}; |
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MODULE_DEVICE_TABLE(spi, xra1403_ids); |
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static const struct of_device_id xra1403_spi_of_match[] = { |
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{ .compatible = "exar,xra1403" }, |
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{}, |
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}; |
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MODULE_DEVICE_TABLE(of, xra1403_spi_of_match); |
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static struct spi_driver xra1403_driver = { |
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.probe = xra1403_probe, |
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.id_table = xra1403_ids, |
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.driver = { |
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.name = "xra1403", |
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.of_match_table = of_match_ptr(xra1403_spi_of_match), |
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}, |
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}; |
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module_spi_driver(xra1403_driver); |
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MODULE_AUTHOR("Nandor Han <[email protected]>"); |
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MODULE_AUTHOR("Semi Malinen <[email protected]>"); |
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MODULE_DESCRIPTION("GPIO expander driver for EXAR XRA1403"); |
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MODULE_LICENSE("GPL v2");
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