drivers/soc/fsl/qe/gpio.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * QUICC Engine GPIOs
   4  *
   5  * Copyright (c) MontaVista Software, Inc. 2008.
   6  *
   7  * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/init.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/err.h>
  14 #include <linux/io.h>
  15 #include <linux/of.h>
  16 #include <linux/of_gpio.h>
  17 #include <linux/gpio/driver.h>
  18 /* FIXME: needed for gpio_to_chip() get rid of this */
  19 #include <linux/gpio.h>
  20 #include <linux/slab.h>
  21 #include <linux/export.h>
  22 #include <soc/fsl/qe/qe.h>
  23
  24 struct qe_gpio_chip {
  25         struct of_mm_gpio_chip mm_gc;
  26         spinlock_t lock;
  27
  28         unsigned long pin_flags[QE_PIO_PINS];
  29 #define QE_PIN_REQUESTED 0
  30
  31         /* shadowed data register to clear/set bits safely */
  32         u32 cpdata;
  33
  34         /* saved_regs used to restore dedicated functions */
  35         struct qe_pio_regs saved_regs;
  36 };
  37
  38 static void qe_gpio_save_regs(struct of_mm_gpio_chip *mm_gc)
  39 {
  40         struct qe_gpio_chip *qe_gc =
  41                 container_of(mm_gc, struct qe_gpio_chip, mm_gc);
  42         struct qe_pio_regs __iomem *regs = mm_gc->regs;
  43
  44         qe_gc->cpdata = in_be32(&regs->cpdata);
  45         qe_gc->saved_regs.cpdata = qe_gc->cpdata;
  46         qe_gc->saved_regs.cpdir1 = in_be32(&regs->cpdir1);
  47         qe_gc->saved_regs.cpdir2 = in_be32(&regs->cpdir2);
  48         qe_gc->saved_regs.cppar1 = in_be32(&regs->cppar1);
  49         qe_gc->saved_regs.cppar2 = in_be32(&regs->cppar2);
  50         qe_gc->saved_regs.cpodr = in_be32(&regs->cpodr);
  51 }
  52
  53 static int qe_gpio_get(struct gpio_chip *gc, unsigned int gpio)
  54 {
  55         struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
  56         struct qe_pio_regs __iomem *regs = mm_gc->regs;
  57         u32 pin_mask = 1 << (QE_PIO_PINS - 1 - gpio);
  58
  59         return !!(in_be32(&regs->cpdata) & pin_mask);
  60 }
  61
  62 static void qe_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
  63 {
  64         struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
  65         struct qe_gpio_chip *qe_gc = gpiochip_get_data(gc);
  66         struct qe_pio_regs __iomem *regs = mm_gc->regs;
  67         unsigned long flags;
  68         u32 pin_mask = 1 << (QE_PIO_PINS - 1 - gpio);
  69
  70         spin_lock_irqsave(&qe_gc->lock, flags);
  71
  72         if (val)
  73                 qe_gc->cpdata |= pin_mask;
  74         else
  75                 qe_gc->cpdata &= ~pin_mask;
  76
  77         out_be32(&regs->cpdata, qe_gc->cpdata);
  78
  79         spin_unlock_irqrestore(&qe_gc->lock, flags);
  80 }
  81
  82 static void qe_gpio_set_multiple(struct gpio_chip *gc,
  83                                  unsigned long *mask, unsigned long *bits)
  84 {
  85         struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
  86         struct qe_gpio_chip *qe_gc = gpiochip_get_data(gc);
  87         struct qe_pio_regs __iomem *regs = mm_gc->regs;
  88         unsigned long flags;
  89         int i;
  90
  91         spin_lock_irqsave(&qe_gc->lock, flags);
  92
  93         for (i = 0; i < gc->ngpio; i++) {
  94                 if (*mask == 0)
  95                         break;
  96                 if (__test_and_clear_bit(i, mask)) {
  97                         if (test_bit(i, bits))
  98                                 qe_gc->cpdata |= (1U << (QE_PIO_PINS - 1 - i));
  99                         else
 100                                 qe_gc->cpdata &= ~(1U << (QE_PIO_PINS - 1 - i));
 101                 }
 102         }
 103
 104         out_be32(&regs->cpdata, qe_gc->cpdata);
 105
 106         spin_unlock_irqrestore(&qe_gc->lock, flags);
 107 }
 108
 109 static int qe_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
 110 {
 111         struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
 112         struct qe_gpio_chip *qe_gc = gpiochip_get_data(gc);
 113         unsigned long flags;
 114
 115         spin_lock_irqsave(&qe_gc->lock, flags);
 116
 117         __par_io_config_pin(mm_gc->regs, gpio, QE_PIO_DIR_IN, 0, 0, 0);
 118
 119         spin_unlock_irqrestore(&qe_gc->lock, flags);
 120
 121         return 0;
 122 }
 123
 124 static int qe_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
 125 {
 126         struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
 127         struct qe_gpio_chip *qe_gc = gpiochip_get_data(gc);
 128         unsigned long flags;
 129
 130         qe_gpio_set(gc, gpio, val);
 131
 132         spin_lock_irqsave(&qe_gc->lock, flags);
 133
 134         __par_io_config_pin(mm_gc->regs, gpio, QE_PIO_DIR_OUT, 0, 0, 0);
 135
 136         spin_unlock_irqrestore(&qe_gc->lock, flags);
 137
 138         return 0;
 139 }
 140
 141 struct qe_pin {
 142         /*
 143          * The qe_gpio_chip name is unfortunate, we should change that to
 144          * something like qe_pio_controller. Someday.
 145          */
 146         struct qe_gpio_chip *controller;
 147         int num;
 148 };
 149
 150 /**
 151  * qe_pin_request - Request a QE pin
 152  * @np:         device node to get a pin from
 153  * @index:      index of a pin in the device tree
 154  * Context:     non-atomic
 155  *
 156  * This function return qe_pin so that you could use it with the rest of
 157  * the QE Pin Multiplexing API.
 158  */
 159 struct qe_pin *qe_pin_request(struct device_node *np, int index)
 160 {
 161         struct qe_pin *qe_pin;
 162         struct gpio_chip *gc;
 163         struct of_mm_gpio_chip *mm_gc;
 164         struct qe_gpio_chip *qe_gc;
 165         int err;
 166         unsigned long flags;
 167
 168         qe_pin = kzalloc(sizeof(*qe_pin), GFP_KERNEL);
 169         if (!qe_pin) {
 170                 pr_debug("%s: can't allocate memory\n", __func__);
 171                 return ERR_PTR(-ENOMEM);
 172         }
 173
 174         err = of_get_gpio(np, index);
 175         if (err < 0)
 176                 goto err0;
 177         gc = gpio_to_chip(err);
 178         if (WARN_ON(!gc)) {
 179                 err = -ENODEV;
 180                 goto err0;
 181         }
 182
 183         if (!of_device_is_compatible(gc->of_node, "fsl,mpc8323-qe-pario-bank")) {
 184                 pr_debug("%s: tried to get a non-qe pin\n", __func__);
 185                 err = -EINVAL;
 186                 goto err0;
 187         }
 188
 189         mm_gc = to_of_mm_gpio_chip(gc);
 190         qe_gc = gpiochip_get_data(gc);
 191
 192         spin_lock_irqsave(&qe_gc->lock, flags);
 193
 194         err -= gc->base;
 195         if (test_and_set_bit(QE_PIN_REQUESTED, &qe_gc->pin_flags[err]) == 0) {
 196                 qe_pin->controller = qe_gc;
 197                 qe_pin->num = err;
 198                 err = 0;
 199         } else {
 200                 err = -EBUSY;
 201         }
 202
 203         spin_unlock_irqrestore(&qe_gc->lock, flags);
 204
 205         if (!err)
 206                 return qe_pin;
 207 err0:
 208         kfree(qe_pin);
 209         pr_debug("%s failed with status %d\n", __func__, err);
 210         return ERR_PTR(err);
 211 }
 212 EXPORT_SYMBOL(qe_pin_request);
 213
 214 /**
 215  * qe_pin_free - Free a pin
 216  * @qe_pin:     pointer to the qe_pin structure
 217  * Context:     any
 218  *
 219  * This function frees the qe_pin structure and makes a pin available
 220  * for further qe_pin_request() calls.
 221  */
 222 void qe_pin_free(struct qe_pin *qe_pin)
 223 {
 224         struct qe_gpio_chip *qe_gc = qe_pin->controller;
 225         unsigned long flags;
 226         const int pin = qe_pin->num;
 227
 228         spin_lock_irqsave(&qe_gc->lock, flags);
 229         test_and_clear_bit(QE_PIN_REQUESTED, &qe_gc->pin_flags[pin]);
 230         spin_unlock_irqrestore(&qe_gc->lock, flags);
 231
 232         kfree(qe_pin);
 233 }
 234 EXPORT_SYMBOL(qe_pin_free);
 235
 236 /**
 237  * qe_pin_set_dedicated - Revert a pin to a dedicated peripheral function mode
 238  * @qe_pin:     pointer to the qe_pin structure
 239  * Context:     any
 240  *
 241  * This function resets a pin to a dedicated peripheral function that
 242  * has been set up by the firmware.
 243  */
 244 void qe_pin_set_dedicated(struct qe_pin *qe_pin)
 245 {
 246         struct qe_gpio_chip *qe_gc = qe_pin->controller;
 247         struct qe_pio_regs __iomem *regs = qe_gc->mm_gc.regs;
 248         struct qe_pio_regs *sregs = &qe_gc->saved_regs;
 249         int pin = qe_pin->num;
 250         u32 mask1 = 1 << (QE_PIO_PINS - (pin + 1));
 251         u32 mask2 = 0x3 << (QE_PIO_PINS - (pin % (QE_PIO_PINS / 2) + 1) * 2);
 252         bool second_reg = pin > (QE_PIO_PINS / 2) - 1;
 253         unsigned long flags;
 254
 255         spin_lock_irqsave(&qe_gc->lock, flags);
 256
 257         if (second_reg) {
 258                 clrsetbits_be32(&regs->cpdir2, mask2, sregs->cpdir2 & mask2);
 259                 clrsetbits_be32(&regs->cppar2, mask2, sregs->cppar2 & mask2);
 260         } else {
 261                 clrsetbits_be32(&regs->cpdir1, mask2, sregs->cpdir1 & mask2);
 262                 clrsetbits_be32(&regs->cppar1, mask2, sregs->cppar1 & mask2);
 263         }
 264
 265         if (sregs->cpdata & mask1)
 266                 qe_gc->cpdata |= mask1;
 267         else
 268                 qe_gc->cpdata &= ~mask1;
 269
 270         out_be32(&regs->cpdata, qe_gc->cpdata);
 271         clrsetbits_be32(&regs->cpodr, mask1, sregs->cpodr & mask1);
 272
 273         spin_unlock_irqrestore(&qe_gc->lock, flags);
 274 }
 275 EXPORT_SYMBOL(qe_pin_set_dedicated);
 276
 277 /**
 278  * qe_pin_set_gpio - Set a pin to the GPIO mode
 279  * @qe_pin:     pointer to the qe_pin structure
 280  * Context:     any
 281  *
 282  * This function sets a pin to the GPIO mode.
 283  */
 284 void qe_pin_set_gpio(struct qe_pin *qe_pin)
 285 {
 286         struct qe_gpio_chip *qe_gc = qe_pin->controller;
 287         struct qe_pio_regs __iomem *regs = qe_gc->mm_gc.regs;
 288         unsigned long flags;
 289
 290         spin_lock_irqsave(&qe_gc->lock, flags);
 291
 292         /* Let's make it input by default, GPIO API is able to change that. */
 293         __par_io_config_pin(regs, qe_pin->num, QE_PIO_DIR_IN, 0, 0, 0);
 294
 295         spin_unlock_irqrestore(&qe_gc->lock, flags);
 296 }
 297 EXPORT_SYMBOL(qe_pin_set_gpio);
 298
 299 static int __init qe_add_gpiochips(void)
 300 {
 301         struct device_node *np;
 302
 303         for_each_compatible_node(np, NULL, "fsl,mpc8323-qe-pario-bank") {
 304                 int ret;
 305                 struct qe_gpio_chip *qe_gc;
 306                 struct of_mm_gpio_chip *mm_gc;
 307                 struct gpio_chip *gc;
 308
 309                 qe_gc = kzalloc(sizeof(*qe_gc), GFP_KERNEL);
 310                 if (!qe_gc) {
 311                         ret = -ENOMEM;
 312                         goto err;
 313                 }
 314
 315                 spin_lock_init(&qe_gc->lock);
 316
 317                 mm_gc = &qe_gc->mm_gc;
 318                 gc = &mm_gc->gc;
 319
 320                 mm_gc->save_regs = qe_gpio_save_regs;
 321                 gc->ngpio = QE_PIO_PINS;
 322                 gc->direction_input = qe_gpio_dir_in;
 323                 gc->direction_output = qe_gpio_dir_out;
 324                 gc->get = qe_gpio_get;
 325                 gc->set = qe_gpio_set;
 326                 gc->set_multiple = qe_gpio_set_multiple;
 327
 328                 ret = of_mm_gpiochip_add_data(np, mm_gc, qe_gc);
 329                 if (ret)
 330                         goto err;
 331                 continue;
 332 err:
 333                 pr_err("%pOF: registration failed with status %d\n",
 334                        np, ret);
 335                 kfree(qe_gc);
 336                 /* try others anyway */
 337         }
 338         return 0;
 339 }
 340 arch_initcall(qe_add_gpiochips);