Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 1 | /* |
| 2 | * 74Hx164 - Generic serial-in/parallel-out 8-bits shift register GPIO driver |
| 3 | * |
| 4 | * Copyright (C) 2010 Gabor Juhos <juhosg@openwrt.org> |
| 5 | * Copyright (C) 2010 Miguel Gaio <miguel.gaio@efixo.com> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | */ |
| 11 | |
| 12 | #include <linux/init.h> |
| 13 | #include <linux/mutex.h> |
| 14 | #include <linux/spi/spi.h> |
| 15 | #include <linux/spi/74x164.h> |
| 16 | #include <linux/gpio.h> |
| 17 | #include <linux/slab.h> |
Paul Gortmaker | bb207ef | 2011-07-03 13:38:09 -0400 | [diff] [blame] | 18 | #include <linux/module.h> |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 19 | |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 20 | struct gen_74x164_chip { |
| 21 | struct spi_device *spi; |
| 22 | struct gpio_chip gpio_chip; |
| 23 | struct mutex lock; |
| 24 | u8 port_config; |
| 25 | }; |
| 26 | |
Linus Walleij | 12610be | 2011-06-13 10:47:15 +0200 | [diff] [blame] | 27 | static struct gen_74x164_chip *gpio_to_74x164_chip(struct gpio_chip *gc) |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 28 | { |
| 29 | return container_of(gc, struct gen_74x164_chip, gpio_chip); |
| 30 | } |
| 31 | |
| 32 | static int __gen_74x164_write_config(struct gen_74x164_chip *chip) |
| 33 | { |
| 34 | return spi_write(chip->spi, |
| 35 | &chip->port_config, sizeof(chip->port_config)); |
| 36 | } |
| 37 | |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 38 | static int gen_74x164_get_value(struct gpio_chip *gc, unsigned offset) |
| 39 | { |
Linus Walleij | 12610be | 2011-06-13 10:47:15 +0200 | [diff] [blame] | 40 | struct gen_74x164_chip *chip = gpio_to_74x164_chip(gc); |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 41 | int ret; |
| 42 | |
| 43 | mutex_lock(&chip->lock); |
| 44 | ret = (chip->port_config >> offset) & 0x1; |
| 45 | mutex_unlock(&chip->lock); |
| 46 | |
| 47 | return ret; |
| 48 | } |
| 49 | |
| 50 | static void gen_74x164_set_value(struct gpio_chip *gc, |
| 51 | unsigned offset, int val) |
| 52 | { |
Linus Walleij | 12610be | 2011-06-13 10:47:15 +0200 | [diff] [blame] | 53 | struct gen_74x164_chip *chip = gpio_to_74x164_chip(gc); |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 54 | |
| 55 | mutex_lock(&chip->lock); |
| 56 | if (val) |
| 57 | chip->port_config |= (1 << offset); |
| 58 | else |
| 59 | chip->port_config &= ~(1 << offset); |
| 60 | |
| 61 | __gen_74x164_write_config(chip); |
| 62 | mutex_unlock(&chip->lock); |
| 63 | } |
| 64 | |
H Hartley Sweeten | a3cc68c | 2011-05-27 16:35:59 -0700 | [diff] [blame] | 65 | static int gen_74x164_direction_output(struct gpio_chip *gc, |
| 66 | unsigned offset, int val) |
| 67 | { |
| 68 | gen_74x164_set_value(gc, offset, val); |
| 69 | return 0; |
| 70 | } |
| 71 | |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 72 | static int __devinit gen_74x164_probe(struct spi_device *spi) |
| 73 | { |
| 74 | struct gen_74x164_chip *chip; |
| 75 | struct gen_74x164_chip_platform_data *pdata; |
| 76 | int ret; |
| 77 | |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 78 | /* |
| 79 | * bits_per_word cannot be configured in platform data |
| 80 | */ |
| 81 | spi->bits_per_word = 8; |
| 82 | |
| 83 | ret = spi_setup(spi); |
| 84 | if (ret < 0) |
| 85 | return ret; |
| 86 | |
Maxime Ripard | 72eac30 | 2012-09-05 10:40:51 +0200 | [diff] [blame] | 87 | chip = devm_kzalloc(&spi->dev, sizeof(*chip), GFP_KERNEL); |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 88 | if (!chip) |
| 89 | return -ENOMEM; |
| 90 | |
Maxime Ripard | 061505f | 2012-09-07 14:18:12 +0200 | [diff] [blame] | 91 | pdata = spi->dev.platform_data; |
| 92 | if (pdata && pdata->base) |
| 93 | chip->gpio_chip.base = pdata->base; |
| 94 | else |
| 95 | chip->gpio_chip.base = -1; |
| 96 | |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 97 | mutex_init(&chip->lock); |
| 98 | |
| 99 | dev_set_drvdata(&spi->dev, chip); |
| 100 | |
| 101 | chip->spi = spi; |
| 102 | |
H Hartley Sweeten | a3cc68c | 2011-05-27 16:35:59 -0700 | [diff] [blame] | 103 | chip->gpio_chip.label = spi->modalias; |
| 104 | chip->gpio_chip.direction_output = gen_74x164_direction_output; |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 105 | chip->gpio_chip.get = gen_74x164_get_value; |
| 106 | chip->gpio_chip.set = gen_74x164_set_value; |
H Hartley Sweeten | a3cc68c | 2011-05-27 16:35:59 -0700 | [diff] [blame] | 107 | chip->gpio_chip.ngpio = 8; |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 108 | chip->gpio_chip.can_sleep = 1; |
| 109 | chip->gpio_chip.dev = &spi->dev; |
| 110 | chip->gpio_chip.owner = THIS_MODULE; |
| 111 | |
| 112 | ret = __gen_74x164_write_config(chip); |
| 113 | if (ret) { |
| 114 | dev_err(&spi->dev, "Failed writing: %d\n", ret); |
| 115 | goto exit_destroy; |
| 116 | } |
| 117 | |
| 118 | ret = gpiochip_add(&chip->gpio_chip); |
| 119 | if (ret) |
| 120 | goto exit_destroy; |
| 121 | |
| 122 | return ret; |
| 123 | |
| 124 | exit_destroy: |
| 125 | dev_set_drvdata(&spi->dev, NULL); |
| 126 | mutex_destroy(&chip->lock); |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 127 | return ret; |
| 128 | } |
| 129 | |
Axel Lin | fc1599f | 2011-03-10 17:10:45 +0800 | [diff] [blame] | 130 | static int __devexit gen_74x164_remove(struct spi_device *spi) |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 131 | { |
| 132 | struct gen_74x164_chip *chip; |
| 133 | int ret; |
| 134 | |
| 135 | chip = dev_get_drvdata(&spi->dev); |
| 136 | if (chip == NULL) |
| 137 | return -ENODEV; |
| 138 | |
| 139 | dev_set_drvdata(&spi->dev, NULL); |
| 140 | |
| 141 | ret = gpiochip_remove(&chip->gpio_chip); |
Maxime Ripard | 72eac30 | 2012-09-05 10:40:51 +0200 | [diff] [blame] | 142 | if (!ret) |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 143 | mutex_destroy(&chip->lock); |
Maxime Ripard | 72eac30 | 2012-09-05 10:40:51 +0200 | [diff] [blame] | 144 | else |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 145 | dev_err(&spi->dev, "Failed to remove the GPIO controller: %d\n", |
| 146 | ret); |
| 147 | |
| 148 | return ret; |
| 149 | } |
| 150 | |
Maxime Ripard | 0a90a9f | 2012-09-07 14:18:13 +0200 | [diff] [blame^] | 151 | static const struct of_device_id gen_74x164_dt_ids[] = { |
| 152 | { .compatible = "fairchild,74hc595" }, |
| 153 | {}, |
| 154 | }; |
| 155 | MODULE_DEVICE_TABLE(of, gen_74x164_dt_ids); |
| 156 | |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 157 | static struct spi_driver gen_74x164_driver = { |
| 158 | .driver = { |
H Hartley Sweeten | a3cc68c | 2011-05-27 16:35:59 -0700 | [diff] [blame] | 159 | .name = "74x164", |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 160 | .owner = THIS_MODULE, |
Maxime Ripard | 0a90a9f | 2012-09-07 14:18:13 +0200 | [diff] [blame^] | 161 | .of_match_table = of_match_ptr(gen_74x164_dt_ids), |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 162 | }, |
| 163 | .probe = gen_74x164_probe, |
| 164 | .remove = __devexit_p(gen_74x164_remove), |
| 165 | }; |
Maxime Ripard | ab3b878 | 2012-09-05 10:40:50 +0200 | [diff] [blame] | 166 | module_spi_driver(gen_74x164_driver); |
Miguel Gaio | ead6db08 | 2010-10-27 15:33:18 -0700 | [diff] [blame] | 167 | |
| 168 | MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>"); |
| 169 | MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>"); |
| 170 | MODULE_DESCRIPTION("GPIO expander driver for 74X164 8-bits shift register"); |
| 171 | MODULE_LICENSE("GPL v2"); |