John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 1 | /* |
Michal Simek | 74600ee | 2013-06-03 14:31:17 +0200 | [diff] [blame] | 2 | * Xilinx gpio driver for xps/axi_gpio IP. |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 3 | * |
Michal Simek | 74600ee | 2013-06-03 14:31:17 +0200 | [diff] [blame] | 4 | * Copyright 2008 - 2013 Xilinx, Inc. |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 |
| 8 | * as published by the Free Software Foundation. |
| 9 | * |
| 10 | * You should have received a copy of the GNU General Public License |
| 11 | * along with this program; if not, write to the Free Software |
| 12 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 13 | */ |
| 14 | |
Michal Simek | 74600ee | 2013-06-03 14:31:17 +0200 | [diff] [blame] | 15 | #include <linux/bitops.h> |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 16 | #include <linux/init.h> |
| 17 | #include <linux/errno.h> |
Paul Gortmaker | bb207ef | 2011-07-03 13:38:09 -0400 | [diff] [blame] | 18 | #include <linux/module.h> |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 19 | #include <linux/of_device.h> |
| 20 | #include <linux/of_platform.h> |
| 21 | #include <linux/of_gpio.h> |
| 22 | #include <linux/io.h> |
| 23 | #include <linux/gpio.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 24 | #include <linux/slab.h> |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 25 | |
| 26 | /* Register Offset Definitions */ |
| 27 | #define XGPIO_DATA_OFFSET (0x0) /* Data register */ |
| 28 | #define XGPIO_TRI_OFFSET (0x4) /* I/O direction register */ |
| 29 | |
Michal Simek | 74600ee | 2013-06-03 14:31:17 +0200 | [diff] [blame] | 30 | #define XGPIO_CHANNEL_OFFSET 0x8 |
| 31 | |
| 32 | /* Read/Write access to the GPIO registers */ |
Michal Simek | cc090d6 | 2013-06-03 14:31:18 +0200 | [diff] [blame] | 33 | #ifdef CONFIG_ARCH_ZYNQ |
| 34 | # define xgpio_readreg(offset) readl(offset) |
| 35 | # define xgpio_writereg(offset, val) writel(val, offset) |
| 36 | #else |
| 37 | # define xgpio_readreg(offset) __raw_readl(offset) |
| 38 | # define xgpio_writereg(offset, val) __raw_writel(val, offset) |
| 39 | #endif |
Michal Simek | 74600ee | 2013-06-03 14:31:17 +0200 | [diff] [blame] | 40 | |
| 41 | /** |
| 42 | * struct xgpio_instance - Stores information about GPIO device |
| 43 | * struct of_mm_gpio_chip mmchip: OF GPIO chip for memory mapped banks |
| 44 | * gpio_state: GPIO state shadow register |
| 45 | * gpio_dir: GPIO direction shadow register |
| 46 | * offset: GPIO channel offset |
| 47 | * gpio_lock: Lock used for synchronization |
| 48 | */ |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 49 | struct xgpio_instance { |
| 50 | struct of_mm_gpio_chip mmchip; |
Michal Simek | 74600ee | 2013-06-03 14:31:17 +0200 | [diff] [blame] | 51 | u32 gpio_state; |
| 52 | u32 gpio_dir; |
| 53 | u32 offset; |
| 54 | spinlock_t gpio_lock; |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 55 | }; |
| 56 | |
| 57 | /** |
| 58 | * xgpio_get - Read the specified signal of the GPIO device. |
| 59 | * @gc: Pointer to gpio_chip device structure. |
| 60 | * @gpio: GPIO signal number. |
| 61 | * |
| 62 | * This function reads the specified signal of the GPIO device. It returns 0 if |
| 63 | * the signal clear, 1 if signal is set or negative value on error. |
| 64 | */ |
| 65 | static int xgpio_get(struct gpio_chip *gc, unsigned int gpio) |
| 66 | { |
| 67 | struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); |
Michal Simek | 74600ee | 2013-06-03 14:31:17 +0200 | [diff] [blame] | 68 | struct xgpio_instance *chip = |
| 69 | container_of(mm_gc, struct xgpio_instance, mmchip); |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 70 | |
Michal Simek | 74600ee | 2013-06-03 14:31:17 +0200 | [diff] [blame] | 71 | void __iomem *regs = mm_gc->regs + chip->offset; |
| 72 | |
| 73 | return !!(xgpio_readreg(regs + XGPIO_DATA_OFFSET) & BIT(gpio)); |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 74 | } |
| 75 | |
| 76 | /** |
| 77 | * xgpio_set - Write the specified signal of the GPIO device. |
| 78 | * @gc: Pointer to gpio_chip device structure. |
| 79 | * @gpio: GPIO signal number. |
| 80 | * @val: Value to be written to specified signal. |
| 81 | * |
| 82 | * This function writes the specified value in to the specified signal of the |
| 83 | * GPIO device. |
| 84 | */ |
| 85 | static void xgpio_set(struct gpio_chip *gc, unsigned int gpio, int val) |
| 86 | { |
| 87 | unsigned long flags; |
| 88 | struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); |
| 89 | struct xgpio_instance *chip = |
| 90 | container_of(mm_gc, struct xgpio_instance, mmchip); |
Michal Simek | 74600ee | 2013-06-03 14:31:17 +0200 | [diff] [blame] | 91 | void __iomem *regs = mm_gc->regs; |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 92 | |
| 93 | spin_lock_irqsave(&chip->gpio_lock, flags); |
| 94 | |
| 95 | /* Write to GPIO signal and set its direction to output */ |
| 96 | if (val) |
Michal Simek | 9f7f0b2 | 2013-06-03 14:31:19 +0200 | [diff] [blame] | 97 | chip->gpio_state |= BIT(gpio); |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 98 | else |
Michal Simek | 9f7f0b2 | 2013-06-03 14:31:19 +0200 | [diff] [blame] | 99 | chip->gpio_state &= ~BIT(gpio); |
Michal Simek | 74600ee | 2013-06-03 14:31:17 +0200 | [diff] [blame] | 100 | |
| 101 | xgpio_writereg(regs + chip->offset + XGPIO_DATA_OFFSET, |
| 102 | chip->gpio_state); |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 103 | |
| 104 | spin_unlock_irqrestore(&chip->gpio_lock, flags); |
| 105 | } |
| 106 | |
| 107 | /** |
| 108 | * xgpio_dir_in - Set the direction of the specified GPIO signal as input. |
| 109 | * @gc: Pointer to gpio_chip device structure. |
| 110 | * @gpio: GPIO signal number. |
| 111 | * |
| 112 | * This function sets the direction of specified GPIO signal as input. |
| 113 | * It returns 0 if direction of GPIO signals is set as input otherwise it |
| 114 | * returns negative error value. |
| 115 | */ |
| 116 | static int xgpio_dir_in(struct gpio_chip *gc, unsigned int gpio) |
| 117 | { |
| 118 | unsigned long flags; |
| 119 | struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); |
| 120 | struct xgpio_instance *chip = |
| 121 | container_of(mm_gc, struct xgpio_instance, mmchip); |
Michal Simek | 74600ee | 2013-06-03 14:31:17 +0200 | [diff] [blame] | 122 | void __iomem *regs = mm_gc->regs; |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 123 | |
| 124 | spin_lock_irqsave(&chip->gpio_lock, flags); |
| 125 | |
| 126 | /* Set the GPIO bit in shadow register and set direction as input */ |
Michal Simek | 9f7f0b2 | 2013-06-03 14:31:19 +0200 | [diff] [blame] | 127 | chip->gpio_dir |= BIT(gpio); |
Michal Simek | 74600ee | 2013-06-03 14:31:17 +0200 | [diff] [blame] | 128 | xgpio_writereg(regs + chip->offset + XGPIO_TRI_OFFSET, chip->gpio_dir); |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 129 | |
| 130 | spin_unlock_irqrestore(&chip->gpio_lock, flags); |
| 131 | |
| 132 | return 0; |
| 133 | } |
| 134 | |
| 135 | /** |
| 136 | * xgpio_dir_out - Set the direction of the specified GPIO signal as output. |
| 137 | * @gc: Pointer to gpio_chip device structure. |
| 138 | * @gpio: GPIO signal number. |
| 139 | * @val: Value to be written to specified signal. |
| 140 | * |
| 141 | * This function sets the direction of specified GPIO signal as output. If all |
| 142 | * GPIO signals of GPIO chip is configured as input then it returns |
| 143 | * error otherwise it returns 0. |
| 144 | */ |
| 145 | static int xgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val) |
| 146 | { |
| 147 | unsigned long flags; |
| 148 | struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); |
| 149 | struct xgpio_instance *chip = |
| 150 | container_of(mm_gc, struct xgpio_instance, mmchip); |
Michal Simek | 74600ee | 2013-06-03 14:31:17 +0200 | [diff] [blame] | 151 | void __iomem *regs = mm_gc->regs; |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 152 | |
| 153 | spin_lock_irqsave(&chip->gpio_lock, flags); |
| 154 | |
| 155 | /* Write state of GPIO signal */ |
| 156 | if (val) |
Michal Simek | 9f7f0b2 | 2013-06-03 14:31:19 +0200 | [diff] [blame] | 157 | chip->gpio_state |= BIT(gpio); |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 158 | else |
Michal Simek | 9f7f0b2 | 2013-06-03 14:31:19 +0200 | [diff] [blame] | 159 | chip->gpio_state &= ~BIT(gpio); |
Michal Simek | 74600ee | 2013-06-03 14:31:17 +0200 | [diff] [blame] | 160 | xgpio_writereg(regs + chip->offset + XGPIO_DATA_OFFSET, |
| 161 | chip->gpio_state); |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 162 | |
| 163 | /* Clear the GPIO bit in shadow register and set direction as output */ |
Michal Simek | 9f7f0b2 | 2013-06-03 14:31:19 +0200 | [diff] [blame] | 164 | chip->gpio_dir &= ~BIT(gpio); |
Michal Simek | 74600ee | 2013-06-03 14:31:17 +0200 | [diff] [blame] | 165 | xgpio_writereg(regs + chip->offset + XGPIO_TRI_OFFSET, chip->gpio_dir); |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 166 | |
| 167 | spin_unlock_irqrestore(&chip->gpio_lock, flags); |
| 168 | |
| 169 | return 0; |
| 170 | } |
| 171 | |
| 172 | /** |
| 173 | * xgpio_save_regs - Set initial values of GPIO pins |
| 174 | * @mm_gc: pointer to memory mapped GPIO chip structure |
| 175 | */ |
| 176 | static void xgpio_save_regs(struct of_mm_gpio_chip *mm_gc) |
| 177 | { |
| 178 | struct xgpio_instance *chip = |
| 179 | container_of(mm_gc, struct xgpio_instance, mmchip); |
| 180 | |
Michal Simek | 74600ee | 2013-06-03 14:31:17 +0200 | [diff] [blame] | 181 | xgpio_writereg(mm_gc->regs + chip->offset + XGPIO_DATA_OFFSET, |
| 182 | chip->gpio_state); |
| 183 | xgpio_writereg(mm_gc->regs + chip->offset + XGPIO_TRI_OFFSET, |
| 184 | chip->gpio_dir); |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 185 | } |
| 186 | |
| 187 | /** |
| 188 | * xgpio_of_probe - Probe method for the GPIO device. |
| 189 | * @np: pointer to device tree node |
| 190 | * |
| 191 | * This function probes the GPIO device in the device tree. It initializes the |
| 192 | * driver data structure. It returns 0, if the driver is bound to the GPIO |
| 193 | * device, or a negative value if there is an error. |
| 194 | */ |
Bill Pemberton | 3836309 | 2012-11-19 13:22:34 -0500 | [diff] [blame] | 195 | static int xgpio_of_probe(struct device_node *np) |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 196 | { |
| 197 | struct xgpio_instance *chip; |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 198 | int status = 0; |
| 199 | const u32 *tree_info; |
Gernot Vormayr | 1b4c5a6 | 2014-09-24 00:58:45 +0200 | [diff] [blame^] | 200 | u32 ngpio; |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 201 | |
| 202 | chip = kzalloc(sizeof(*chip), GFP_KERNEL); |
| 203 | if (!chip) |
| 204 | return -ENOMEM; |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 205 | |
| 206 | /* Update GPIO state shadow register with default value */ |
Michal Simek | 6f8bf50 | 2013-06-03 14:31:16 +0200 | [diff] [blame] | 207 | of_property_read_u32(np, "xlnx,dout-default", &chip->gpio_state); |
| 208 | |
| 209 | /* By default, all pins are inputs */ |
| 210 | chip->gpio_dir = 0xFFFFFFFF; |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 211 | |
| 212 | /* Update GPIO direction shadow register with default value */ |
Michal Simek | 6f8bf50 | 2013-06-03 14:31:16 +0200 | [diff] [blame] | 213 | of_property_read_u32(np, "xlnx,tri-default", &chip->gpio_dir); |
| 214 | |
Gernot Vormayr | 1b4c5a6 | 2014-09-24 00:58:45 +0200 | [diff] [blame^] | 215 | /* |
| 216 | * Check device node and parent device node for device width |
| 217 | * and assume default width of 32 |
| 218 | */ |
| 219 | if (of_property_read_u32(np, "xlnx,gpio-width", &ngpio)) |
| 220 | ngpio = 32; |
| 221 | chip->mmchip.gc.ngpio = (u16)ngpio; |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 222 | |
| 223 | spin_lock_init(&chip->gpio_lock); |
| 224 | |
Anton Vorontsov | a19e3da | 2010-06-08 07:48:16 -0600 | [diff] [blame] | 225 | chip->mmchip.gc.direction_input = xgpio_dir_in; |
| 226 | chip->mmchip.gc.direction_output = xgpio_dir_out; |
| 227 | chip->mmchip.gc.get = xgpio_get; |
| 228 | chip->mmchip.gc.set = xgpio_set; |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 229 | |
| 230 | chip->mmchip.save_regs = xgpio_save_regs; |
| 231 | |
| 232 | /* Call the OF gpio helper to setup and register the GPIO device */ |
| 233 | status = of_mm_gpiochip_add(np, &chip->mmchip); |
| 234 | if (status) { |
| 235 | kfree(chip); |
| 236 | pr_err("%s: error in probe function with status %d\n", |
| 237 | np->full_name, status); |
| 238 | return status; |
| 239 | } |
Michal Simek | 74600ee | 2013-06-03 14:31:17 +0200 | [diff] [blame] | 240 | |
| 241 | pr_info("XGpio: %s: registered, base is %d\n", np->full_name, |
| 242 | chip->mmchip.gc.base); |
| 243 | |
| 244 | tree_info = of_get_property(np, "xlnx,is-dual", NULL); |
| 245 | if (tree_info && be32_to_cpup(tree_info)) { |
| 246 | chip = kzalloc(sizeof(*chip), GFP_KERNEL); |
| 247 | if (!chip) |
| 248 | return -ENOMEM; |
| 249 | |
| 250 | /* Add dual channel offset */ |
| 251 | chip->offset = XGPIO_CHANNEL_OFFSET; |
| 252 | |
| 253 | /* Update GPIO state shadow register with default value */ |
| 254 | of_property_read_u32(np, "xlnx,dout-default-2", |
| 255 | &chip->gpio_state); |
| 256 | |
| 257 | /* By default, all pins are inputs */ |
| 258 | chip->gpio_dir = 0xFFFFFFFF; |
| 259 | |
| 260 | /* Update GPIO direction shadow register with default value */ |
| 261 | of_property_read_u32(np, "xlnx,tri-default-2", &chip->gpio_dir); |
| 262 | |
Gernot Vormayr | 1b4c5a6 | 2014-09-24 00:58:45 +0200 | [diff] [blame^] | 263 | /* |
| 264 | * Check device node and parent device node for device width |
| 265 | * and assume default width of 32 |
| 266 | */ |
| 267 | if (of_property_read_u32(np, "xlnx,gpio2-width", &ngpio)) |
| 268 | ngpio = 32; |
| 269 | chip->mmchip.gc.ngpio = (u16)ngpio; |
Michal Simek | 74600ee | 2013-06-03 14:31:17 +0200 | [diff] [blame] | 270 | |
| 271 | spin_lock_init(&chip->gpio_lock); |
| 272 | |
| 273 | chip->mmchip.gc.direction_input = xgpio_dir_in; |
| 274 | chip->mmchip.gc.direction_output = xgpio_dir_out; |
| 275 | chip->mmchip.gc.get = xgpio_get; |
| 276 | chip->mmchip.gc.set = xgpio_set; |
| 277 | |
| 278 | chip->mmchip.save_regs = xgpio_save_regs; |
| 279 | |
| 280 | /* Call the OF gpio helper to setup and register the GPIO dev */ |
| 281 | status = of_mm_gpiochip_add(np, &chip->mmchip); |
| 282 | if (status) { |
| 283 | kfree(chip); |
| 284 | pr_err("%s: error in probe function with status %d\n", |
| 285 | np->full_name, status); |
| 286 | return status; |
| 287 | } |
| 288 | pr_info("XGpio: %s: dual channel registered, base is %d\n", |
| 289 | np->full_name, chip->mmchip.gc.base); |
| 290 | } |
| 291 | |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 292 | return 0; |
| 293 | } |
| 294 | |
Jingoo Han | 9992bc9 | 2014-05-07 18:08:20 +0900 | [diff] [blame] | 295 | static const struct of_device_id xgpio_of_match[] = { |
John Linn | 0bcb606 | 2008-11-12 13:25:38 -0800 | [diff] [blame] | 296 | { .compatible = "xlnx,xps-gpio-1.00.a", }, |
| 297 | { /* end of list */ }, |
| 298 | }; |
| 299 | |
| 300 | static int __init xgpio_init(void) |
| 301 | { |
| 302 | struct device_node *np; |
| 303 | |
| 304 | for_each_matching_node(np, xgpio_of_match) |
| 305 | xgpio_of_probe(np); |
| 306 | |
| 307 | return 0; |
| 308 | } |
| 309 | |
| 310 | /* Make sure we get initialized before anyone else tries to use us */ |
| 311 | subsys_initcall(xgpio_init); |
| 312 | /* No exit call at the moment as we cannot unregister of GPIO chips */ |
| 313 | |
| 314 | MODULE_AUTHOR("Xilinx, Inc."); |
| 315 | MODULE_DESCRIPTION("Xilinx GPIO driver"); |
| 316 | MODULE_LICENSE("GPL"); |