1 /* 2 * QUICC Engine GPIOs 3 * 4 * Copyright (c) MontaVista Software, Inc. 2008. 5 * 6 * Author: Anton Vorontsov <avorontsov@ru.mvista.com> 7 * 8 * This program is free software; you can redistribute it and/or modify it 9 * under the terms of the GNU General Public License as published by the 10 * Free Software Foundation; either version 2 of the License, or (at your 11 * option) any later version. 12 */ 13 14 #include <linux/kernel.h> 15 #include <linux/init.h> 16 #include <linux/spinlock.h> 17 #include <linux/err.h> 18 #include <linux/io.h> 19 #include <linux/of.h> 20 #include <linux/of_gpio.h> 21 #include <linux/gpio/driver.h> 22 /* FIXME: needed for gpio_to_chip() get rid of this */ 23 #include <linux/gpio.h> 24 #include <linux/slab.h> 25 #include <linux/export.h> 26 #include <soc/fsl/qe/qe.h> 27 28 struct qe_gpio_chip { 29 struct of_mm_gpio_chip mm_gc; 30 spinlock_t lock; 31 32 unsigned long pin_flags[QE_PIO_PINS]; 33 #define QE_PIN_REQUESTED 0 34 35 /* shadowed data register to clear/set bits safely */ 36 u32 cpdata; 37 38 /* saved_regs used to restore dedicated functions */ 39 struct qe_pio_regs saved_regs; 40 }; 41 42 static void qe_gpio_save_regs(struct of_mm_gpio_chip *mm_gc) 43 { 44 struct qe_gpio_chip *qe_gc = 45 container_of(mm_gc, struct qe_gpio_chip, mm_gc); 46 struct qe_pio_regs __iomem *regs = mm_gc->regs; 47 48 qe_gc->cpdata = in_be32(®s->cpdata); 49 qe_gc->saved_regs.cpdata = qe_gc->cpdata; 50 qe_gc->saved_regs.cpdir1 = in_be32(®s->cpdir1); 51 qe_gc->saved_regs.cpdir2 = in_be32(®s->cpdir2); 52 qe_gc->saved_regs.cppar1 = in_be32(®s->cppar1); 53 qe_gc->saved_regs.cppar2 = in_be32(®s->cppar2); 54 qe_gc->saved_regs.cpodr = in_be32(®s->cpodr); 55 } 56 57 static int qe_gpio_get(struct gpio_chip *gc, unsigned int gpio) 58 { 59 struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); 60 struct qe_pio_regs __iomem *regs = mm_gc->regs; 61 u32 pin_mask = 1 << (QE_PIO_PINS - 1 - gpio); 62 63 return !!(in_be32(®s->cpdata) & pin_mask); 64 } 65 66 static void qe_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val) 67 { 68 struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); 69 struct qe_gpio_chip *qe_gc = gpiochip_get_data(gc); 70 struct qe_pio_regs __iomem *regs = mm_gc->regs; 71 unsigned long flags; 72 u32 pin_mask = 1 << (QE_PIO_PINS - 1 - gpio); 73 74 spin_lock_irqsave(&qe_gc->lock, flags); 75 76 if (val) 77 qe_gc->cpdata |= pin_mask; 78 else 79 qe_gc->cpdata &= ~pin_mask; 80 81 out_be32(®s->cpdata, qe_gc->cpdata); 82 83 spin_unlock_irqrestore(&qe_gc->lock, flags); 84 } 85 86 static int qe_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio) 87 { 88 struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); 89 struct qe_gpio_chip *qe_gc = gpiochip_get_data(gc); 90 unsigned long flags; 91 92 spin_lock_irqsave(&qe_gc->lock, flags); 93 94 __par_io_config_pin(mm_gc->regs, gpio, QE_PIO_DIR_IN, 0, 0, 0); 95 96 spin_unlock_irqrestore(&qe_gc->lock, flags); 97 98 return 0; 99 } 100 101 static int qe_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val) 102 { 103 struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); 104 struct qe_gpio_chip *qe_gc = gpiochip_get_data(gc); 105 unsigned long flags; 106 107 qe_gpio_set(gc, gpio, val); 108 109 spin_lock_irqsave(&qe_gc->lock, flags); 110 111 __par_io_config_pin(mm_gc->regs, gpio, QE_PIO_DIR_OUT, 0, 0, 0); 112 113 spin_unlock_irqrestore(&qe_gc->lock, flags); 114 115 return 0; 116 } 117 118 struct qe_pin { 119 /* 120 * The qe_gpio_chip name is unfortunate, we should change that to 121 * something like qe_pio_controller. Someday. 122 */ 123 struct qe_gpio_chip *controller; 124 int num; 125 }; 126 127 /** 128 * qe_pin_request - Request a QE pin 129 * @np: device node to get a pin from 130 * @index: index of a pin in the device tree 131 * Context: non-atomic 132 * 133 * This function return qe_pin so that you could use it with the rest of 134 * the QE Pin Multiplexing API. 135 */ 136 struct qe_pin *qe_pin_request(struct device_node *np, int index) 137 { 138 struct qe_pin *qe_pin; 139 struct gpio_chip *gc; 140 struct of_mm_gpio_chip *mm_gc; 141 struct qe_gpio_chip *qe_gc; 142 int err; 143 unsigned long flags; 144 145 qe_pin = kzalloc(sizeof(*qe_pin), GFP_KERNEL); 146 if (!qe_pin) { 147 pr_debug("%s: can't allocate memory\n", __func__); 148 return ERR_PTR(-ENOMEM); 149 } 150 151 err = of_get_gpio(np, index); 152 if (err < 0) 153 goto err0; 154 gc = gpio_to_chip(err); 155 if (WARN_ON(!gc)) 156 goto err0; 157 158 if (!of_device_is_compatible(gc->of_node, "fsl,mpc8323-qe-pario-bank")) { 159 pr_debug("%s: tried to get a non-qe pin\n", __func__); 160 err = -EINVAL; 161 goto err0; 162 } 163 164 mm_gc = to_of_mm_gpio_chip(gc); 165 qe_gc = gpiochip_get_data(gc); 166 167 spin_lock_irqsave(&qe_gc->lock, flags); 168 169 err -= gc->base; 170 if (test_and_set_bit(QE_PIN_REQUESTED, &qe_gc->pin_flags[err]) == 0) { 171 qe_pin->controller = qe_gc; 172 qe_pin->num = err; 173 err = 0; 174 } else { 175 err = -EBUSY; 176 } 177 178 spin_unlock_irqrestore(&qe_gc->lock, flags); 179 180 if (!err) 181 return qe_pin; 182 err0: 183 kfree(qe_pin); 184 pr_debug("%s failed with status %d\n", __func__, err); 185 return ERR_PTR(err); 186 } 187 EXPORT_SYMBOL(qe_pin_request); 188 189 /** 190 * qe_pin_free - Free a pin 191 * @qe_pin: pointer to the qe_pin structure 192 * Context: any 193 * 194 * This function frees the qe_pin structure and makes a pin available 195 * for further qe_pin_request() calls. 196 */ 197 void qe_pin_free(struct qe_pin *qe_pin) 198 { 199 struct qe_gpio_chip *qe_gc = qe_pin->controller; 200 unsigned long flags; 201 const int pin = qe_pin->num; 202 203 spin_lock_irqsave(&qe_gc->lock, flags); 204 test_and_clear_bit(QE_PIN_REQUESTED, &qe_gc->pin_flags[pin]); 205 spin_unlock_irqrestore(&qe_gc->lock, flags); 206 207 kfree(qe_pin); 208 } 209 EXPORT_SYMBOL(qe_pin_free); 210 211 /** 212 * qe_pin_set_dedicated - Revert a pin to a dedicated peripheral function mode 213 * @qe_pin: pointer to the qe_pin structure 214 * Context: any 215 * 216 * This function resets a pin to a dedicated peripheral function that 217 * has been set up by the firmware. 218 */ 219 void qe_pin_set_dedicated(struct qe_pin *qe_pin) 220 { 221 struct qe_gpio_chip *qe_gc = qe_pin->controller; 222 struct qe_pio_regs __iomem *regs = qe_gc->mm_gc.regs; 223 struct qe_pio_regs *sregs = &qe_gc->saved_regs; 224 int pin = qe_pin->num; 225 u32 mask1 = 1 << (QE_PIO_PINS - (pin + 1)); 226 u32 mask2 = 0x3 << (QE_PIO_PINS - (pin % (QE_PIO_PINS / 2) + 1) * 2); 227 bool second_reg = pin > (QE_PIO_PINS / 2) - 1; 228 unsigned long flags; 229 230 spin_lock_irqsave(&qe_gc->lock, flags); 231 232 if (second_reg) { 233 clrsetbits_be32(®s->cpdir2, mask2, sregs->cpdir2 & mask2); 234 clrsetbits_be32(®s->cppar2, mask2, sregs->cppar2 & mask2); 235 } else { 236 clrsetbits_be32(®s->cpdir1, mask2, sregs->cpdir1 & mask2); 237 clrsetbits_be32(®s->cppar1, mask2, sregs->cppar1 & mask2); 238 } 239 240 if (sregs->cpdata & mask1) 241 qe_gc->cpdata |= mask1; 242 else 243 qe_gc->cpdata &= ~mask1; 244 245 out_be32(®s->cpdata, qe_gc->cpdata); 246 clrsetbits_be32(®s->cpodr, mask1, sregs->cpodr & mask1); 247 248 spin_unlock_irqrestore(&qe_gc->lock, flags); 249 } 250 EXPORT_SYMBOL(qe_pin_set_dedicated); 251 252 /** 253 * qe_pin_set_gpio - Set a pin to the GPIO mode 254 * @qe_pin: pointer to the qe_pin structure 255 * Context: any 256 * 257 * This function sets a pin to the GPIO mode. 258 */ 259 void qe_pin_set_gpio(struct qe_pin *qe_pin) 260 { 261 struct qe_gpio_chip *qe_gc = qe_pin->controller; 262 struct qe_pio_regs __iomem *regs = qe_gc->mm_gc.regs; 263 unsigned long flags; 264 265 spin_lock_irqsave(&qe_gc->lock, flags); 266 267 /* Let's make it input by default, GPIO API is able to change that. */ 268 __par_io_config_pin(regs, qe_pin->num, QE_PIO_DIR_IN, 0, 0, 0); 269 270 spin_unlock_irqrestore(&qe_gc->lock, flags); 271 } 272 EXPORT_SYMBOL(qe_pin_set_gpio); 273 274 static int __init qe_add_gpiochips(void) 275 { 276 struct device_node *np; 277 278 for_each_compatible_node(np, NULL, "fsl,mpc8323-qe-pario-bank") { 279 int ret; 280 struct qe_gpio_chip *qe_gc; 281 struct of_mm_gpio_chip *mm_gc; 282 struct gpio_chip *gc; 283 284 qe_gc = kzalloc(sizeof(*qe_gc), GFP_KERNEL); 285 if (!qe_gc) { 286 ret = -ENOMEM; 287 goto err; 288 } 289 290 spin_lock_init(&qe_gc->lock); 291 292 mm_gc = &qe_gc->mm_gc; 293 gc = &mm_gc->gc; 294 295 mm_gc->save_regs = qe_gpio_save_regs; 296 gc->ngpio = QE_PIO_PINS; 297 gc->direction_input = qe_gpio_dir_in; 298 gc->direction_output = qe_gpio_dir_out; 299 gc->get = qe_gpio_get; 300 gc->set = qe_gpio_set; 301 302 ret = of_mm_gpiochip_add_data(np, mm_gc, qe_gc); 303 if (ret) 304 goto err; 305 continue; 306 err: 307 pr_err("%s: registration failed with status %d\n", 308 np->full_name, ret); 309 kfree(qe_gc); 310 /* try others anyway */ 311 } 312 return 0; 313 } 314 arch_initcall(qe_add_gpiochips); 315