arch/powerpc/platforms/52xx/mpc52xx_gpt.c

   1 /*
   2  * MPC5200 General Purpose Timer device driver
   3  *
   4  * Copyright (c) 2009 Secret Lab Technologies Ltd.
   5  * Copyright (c) 2008 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
   6  *
   7  * This program is free software; you can redistribute  it and/or modify it
   8  * under  the terms of  the GNU General  Public License as published by the
   9  * Free Software Foundation;  either version 2 of the  License, or (at your
  10  * option) any later version.
  11  *
  12  * This file is a driver for the the General Purpose Timer (gpt) devices
  13  * found on the MPC5200 SoC.  Each timer has an IO pin which can be used
  14  * for GPIO or can be used to raise interrupts.  The timer function can
  15  * be used independently from the IO pin, or it can be used to control
  16  * output signals or measure input signals.
  17  *
  18  * This driver supports the GPIO and IRQ controller functions of the GPT
  19  * device.  Timer functions are not yet supported, nor is the watchdog
  20  * timer.
  21  *
  22  * To use the GPIO function, the following two properties must be added
  23  * to the device tree node for the gpt device (typically in the .dts file
  24  * for the board):
  25  *      gpio-controller;
  26  *      #gpio-cells = < 2 >;
  27  * This driver will register the GPIO pin if it finds the gpio-controller
  28  * property in the device tree.
  29  *
  30  * To use the IRQ controller function, the following two properties must
  31  * be added to the device tree node for the gpt device:
  32  *      interrupt-controller;
  33  *      #interrupt-cells = < 1 >;
  34  * The IRQ controller binding only uses one cell to specify the interrupt,
  35  * and the IRQ flags are encoded in the cell.  A cell is not used to encode
  36  * the IRQ number because the GPT only has a single IRQ source.  For flags,
  37  * a value of '1' means rising edge sensitive and '2' means falling edge.
  38  *
  39  * The GPIO and the IRQ controller functions can be used at the same time,
  40  * but in this use case the IO line will only work as an input.  Trying to
  41  * use it as a GPIO output will not work.
  42  *
  43  * When using the GPIO line as an output, it can either be driven as normal
  44  * IO, or it can be an Open Collector (OC) output.  At the moment it is the
  45  * responsibility of either the bootloader or the platform setup code to set
  46  * the output mode.  This driver does not change the output mode setting.
  47  */
  48
  49 #include <linux/irq.h>
  50 #include <linux/interrupt.h>
  51 #include <linux/io.h>
  52 #include <linux/of.h>
  53 #include <linux/of_platform.h>
  54 #include <linux/of_gpio.h>
  55 #include <linux/kernel.h>
  56 #include <asm/mpc52xx.h>
  57
  58 MODULE_DESCRIPTION("Freescale MPC52xx gpt driver");
  59 MODULE_AUTHOR("Sascha Hauer, Grant Likely");
  60 MODULE_LICENSE("GPL");
  61
  62 /**
  63  * struct mpc52xx_gpt - Private data structure for MPC52xx GPT driver
  64  * @dev: pointer to device structure
  65  * @regs: virtual address of GPT registers
  66  * @lock: spinlock to coordinate between different functions.
  67  * @of_gc: of_gpio_chip instance structure; used when GPIO is enabled
  68  * @irqhost: Pointer to irq_host instance; used when IRQ mode is supported
  69  */
  70 struct mpc52xx_gpt_priv {
  71         struct device *dev;
  72         struct mpc52xx_gpt __iomem *regs;
  73         spinlock_t lock;
  74         struct irq_host *irqhost;
  75
  76 #if defined(CONFIG_GPIOLIB)
  77         struct of_gpio_chip of_gc;
  78 #endif
  79 };
  80
  81 #define MPC52xx_GPT_MODE_MS_MASK        (0x07)
  82 #define MPC52xx_GPT_MODE_MS_IC          (0x01)
  83 #define MPC52xx_GPT_MODE_MS_OC          (0x02)
  84 #define MPC52xx_GPT_MODE_MS_PWM         (0x03)
  85 #define MPC52xx_GPT_MODE_MS_GPIO        (0x04)
  86
  87 #define MPC52xx_GPT_MODE_GPIO_MASK      (0x30)
  88 #define MPC52xx_GPT_MODE_GPIO_OUT_LOW   (0x20)
  89 #define MPC52xx_GPT_MODE_GPIO_OUT_HIGH  (0x30)
  90
  91 #define MPC52xx_GPT_MODE_IRQ_EN         (0x0100)
  92
  93 #define MPC52xx_GPT_MODE_ICT_MASK       (0x030000)
  94 #define MPC52xx_GPT_MODE_ICT_RISING     (0x010000)
  95 #define MPC52xx_GPT_MODE_ICT_FALLING    (0x020000)
  96 #define MPC52xx_GPT_MODE_ICT_TOGGLE     (0x030000)
  97
  98 #define MPC52xx_GPT_STATUS_IRQMASK      (0x000f)
  99
 100 /* ---------------------------------------------------------------------
 101  * Cascaded interrupt controller hooks
 102  */
 103
 104 static void mpc52xx_gpt_irq_unmask(unsigned int virq)
 105 {
 106         struct mpc52xx_gpt_priv *gpt = get_irq_chip_data(virq);
 107         unsigned long flags;
 108
 109         spin_lock_irqsave(&gpt->lock, flags);
 110         setbits32(&gpt->regs->mode, MPC52xx_GPT_MODE_IRQ_EN);
 111         spin_unlock_irqrestore(&gpt->lock, flags);
 112 }
 113
 114 static void mpc52xx_gpt_irq_mask(unsigned int virq)
 115 {
 116         struct mpc52xx_gpt_priv *gpt = get_irq_chip_data(virq);
 117         unsigned long flags;
 118
 119         spin_lock_irqsave(&gpt->lock, flags);
 120         clrbits32(&gpt->regs->mode, MPC52xx_GPT_MODE_IRQ_EN);
 121         spin_unlock_irqrestore(&gpt->lock, flags);
 122 }
 123
 124 static void mpc52xx_gpt_irq_ack(unsigned int virq)
 125 {
 126         struct mpc52xx_gpt_priv *gpt = get_irq_chip_data(virq);
 127
 128         out_be32(&gpt->regs->status, MPC52xx_GPT_STATUS_IRQMASK);
 129 }
 130
 131 static int mpc52xx_gpt_irq_set_type(unsigned int virq, unsigned int flow_type)
 132 {
 133         struct mpc52xx_gpt_priv *gpt = get_irq_chip_data(virq);
 134         unsigned long flags;
 135         u32 reg;
 136
 137         dev_dbg(gpt->dev, "%s: virq=%i type=%x\n", __func__, virq, flow_type);
 138
 139         spin_lock_irqsave(&gpt->lock, flags);
 140         reg = in_be32(&gpt->regs->mode) & ~MPC52xx_GPT_MODE_ICT_MASK;
 141         if (flow_type & IRQF_TRIGGER_RISING)
 142                 reg |= MPC52xx_GPT_MODE_ICT_RISING;
 143         if (flow_type & IRQF_TRIGGER_FALLING)
 144                 reg |= MPC52xx_GPT_MODE_ICT_FALLING;
 145         out_be32(&gpt->regs->mode, reg);
 146         spin_unlock_irqrestore(&gpt->lock, flags);
 147
 148         return 0;
 149 }
 150
 151 static struct irq_chip mpc52xx_gpt_irq_chip = {
 152         .typename = "MPC52xx GPT",
 153         .unmask = mpc52xx_gpt_irq_unmask,
 154         .mask = mpc52xx_gpt_irq_mask,
 155         .ack = mpc52xx_gpt_irq_ack,
 156         .set_type = mpc52xx_gpt_irq_set_type,
 157 };
 158
 159 void mpc52xx_gpt_irq_cascade(unsigned int virq, struct irq_desc *desc)
 160 {
 161         struct mpc52xx_gpt_priv *gpt = get_irq_data(virq);
 162         int sub_virq;
 163         u32 status;
 164
 165         status = in_be32(&gpt->regs->status) & MPC52xx_GPT_STATUS_IRQMASK;
 166         if (status) {
 167                 sub_virq = irq_linear_revmap(gpt->irqhost, 0);
 168                 generic_handle_irq(sub_virq);
 169         }
 170 }
 171
 172 static int mpc52xx_gpt_irq_map(struct irq_host *h, unsigned int virq,
 173                                irq_hw_number_t hw)
 174 {
 175         struct mpc52xx_gpt_priv *gpt = h->host_data;
 176
 177         dev_dbg(gpt->dev, "%s: h=%p, virq=%i\n", __func__, h, virq);
 178         set_irq_chip_data(virq, gpt);
 179         set_irq_chip_and_handler(virq, &mpc52xx_gpt_irq_chip, handle_edge_irq);
 180
 181         return 0;
 182 }
 183
 184 static int mpc52xx_gpt_irq_xlate(struct irq_host *h, struct device_node *ct,
 185                                  u32 *intspec, unsigned int intsize,
 186                                  irq_hw_number_t *out_hwirq,
 187                                  unsigned int *out_flags)
 188 {
 189         struct mpc52xx_gpt_priv *gpt = h->host_data;
 190
 191         dev_dbg(gpt->dev, "%s: flags=%i\n", __func__, intspec[0]);
 192
 193         if ((intsize < 1) || (intspec[0] < 1) || (intspec[0] > 3)) {
 194                 dev_err(gpt->dev, "bad irq specifier in %s\n", ct->full_name);
 195                 return -EINVAL;
 196         }
 197
 198         *out_hwirq = 0; /* The GPT only has 1 IRQ line */
 199         *out_flags = intspec[0];
 200
 201         return 0;
 202 }
 203
 204 static struct irq_host_ops mpc52xx_gpt_irq_ops = {
 205         .map = mpc52xx_gpt_irq_map,
 206         .xlate = mpc52xx_gpt_irq_xlate,
 207 };
 208
 209 static void
 210 mpc52xx_gpt_irq_setup(struct mpc52xx_gpt_priv *gpt, struct device_node *node)
 211 {
 212         int cascade_virq;
 213         unsigned long flags;
 214
 215         /* Only setup cascaded IRQ if device tree claims the GPT is
 216          * an interrupt controller */
 217         if (!of_find_property(node, "interrupt-controller", NULL))
 218                 return;
 219
 220         cascade_virq = irq_of_parse_and_map(node, 0);
 221
 222         gpt->irqhost = irq_alloc_host(node, IRQ_HOST_MAP_LINEAR, 1,
 223                                       &mpc52xx_gpt_irq_ops, -1);
 224         if (!gpt->irqhost) {
 225                 dev_err(gpt->dev, "irq_alloc_host() failed\n");
 226                 return;
 227         }
 228
 229         gpt->irqhost->host_data = gpt;
 230
 231         set_irq_data(cascade_virq, gpt);
 232         set_irq_chained_handler(cascade_virq, mpc52xx_gpt_irq_cascade);
 233
 234         /* Set to Input Capture mode */
 235         spin_lock_irqsave(&gpt->lock, flags);
 236         clrsetbits_be32(&gpt->regs->mode, MPC52xx_GPT_MODE_MS_MASK,
 237                         MPC52xx_GPT_MODE_MS_IC);
 238         spin_unlock_irqrestore(&gpt->lock, flags);
 239
 240         dev_dbg(gpt->dev, "%s() complete. virq=%i\n", __func__, cascade_virq);
 241 }
 242
 243
 244 /* ---------------------------------------------------------------------
 245  * GPIOLIB hooks
 246  */
 247 #if defined(CONFIG_GPIOLIB)
 248 static inline struct mpc52xx_gpt_priv *gc_to_mpc52xx_gpt(struct gpio_chip *gc)
 249 {
 250         return container_of(to_of_gpio_chip(gc), struct mpc52xx_gpt_priv,of_gc);
 251 }
 252
 253 static int mpc52xx_gpt_gpio_get(struct gpio_chip *gc, unsigned int gpio)
 254 {
 255         struct mpc52xx_gpt_priv *gpt = gc_to_mpc52xx_gpt(gc);
 256
 257         return (in_be32(&gpt->regs->status) >> 8) & 1;
 258 }
 259
 260 static void
 261 mpc52xx_gpt_gpio_set(struct gpio_chip *gc, unsigned int gpio, int v)
 262 {
 263         struct mpc52xx_gpt_priv *gpt = gc_to_mpc52xx_gpt(gc);
 264         unsigned long flags;
 265         u32 r;
 266
 267         dev_dbg(gpt->dev, "%s: gpio:%d v:%d\n", __func__, gpio, v);
 268         r = v ? MPC52xx_GPT_MODE_GPIO_OUT_HIGH : MPC52xx_GPT_MODE_GPIO_OUT_LOW;
 269
 270         spin_lock_irqsave(&gpt->lock, flags);
 271         clrsetbits_be32(&gpt->regs->mode, MPC52xx_GPT_MODE_GPIO_MASK, r);
 272         spin_unlock_irqrestore(&gpt->lock, flags);
 273 }
 274
 275 static int mpc52xx_gpt_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
 276 {
 277         struct mpc52xx_gpt_priv *gpt = gc_to_mpc52xx_gpt(gc);
 278         unsigned long flags;
 279
 280         dev_dbg(gpt->dev, "%s: gpio:%d\n", __func__, gpio);
 281
 282         spin_lock_irqsave(&gpt->lock, flags);
 283         clrbits32(&gpt->regs->mode, MPC52xx_GPT_MODE_GPIO_MASK);
 284         spin_unlock_irqrestore(&gpt->lock, flags);
 285
 286         return 0;
 287 }
 288
 289 static int
 290 mpc52xx_gpt_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
 291 {
 292         mpc52xx_gpt_gpio_set(gc, gpio, val);
 293         return 0;
 294 }
 295
 296 static void
 297 mpc52xx_gpt_gpio_setup(struct mpc52xx_gpt_priv *gpt, struct device_node *node)
 298 {
 299         int rc;
 300
 301         /* Only setup GPIO if the device tree claims the GPT is
 302          * a GPIO controller */
 303         if (!of_find_property(node, "gpio-controller", NULL))
 304                 return;
 305
 306         gpt->of_gc.gc.label = kstrdup(node->full_name, GFP_KERNEL);
 307         if (!gpt->of_gc.gc.label) {
 308                 dev_err(gpt->dev, "out of memory\n");
 309                 return;
 310         }
 311
 312         gpt->of_gc.gpio_cells = 2;
 313         gpt->of_gc.gc.ngpio = 1;
 314         gpt->of_gc.gc.direction_input  = mpc52xx_gpt_gpio_dir_in;
 315         gpt->of_gc.gc.direction_output = mpc52xx_gpt_gpio_dir_out;
 316         gpt->of_gc.gc.get = mpc52xx_gpt_gpio_get;
 317         gpt->of_gc.gc.set = mpc52xx_gpt_gpio_set;
 318         gpt->of_gc.gc.base = -1;
 319         gpt->of_gc.xlate = of_gpio_simple_xlate;
 320         node->data = &gpt->of_gc;
 321         of_node_get(node);
 322
 323         /* Setup external pin in GPIO mode */
 324         clrsetbits_be32(&gpt->regs->mode, MPC52xx_GPT_MODE_MS_MASK,
 325                         MPC52xx_GPT_MODE_MS_GPIO);
 326
 327         rc = gpiochip_add(&gpt->of_gc.gc);
 328         if (rc)
 329                 dev_err(gpt->dev, "gpiochip_add() failed; rc=%i\n", rc);
 330
 331         dev_dbg(gpt->dev, "%s() complete.\n", __func__);
 332 }
 333 #else /* defined(CONFIG_GPIOLIB) */
 334 static void
 335 mpc52xx_gpt_gpio_setup(struct mpc52xx_gpt_priv *p, struct device_node *np) { }
 336 #endif /* defined(CONFIG_GPIOLIB) */
 337
 338 /***********************************************************************
 339  * SYSFS attributes
 340  */
 341 #if defined(CONFIG_SYSFS)
 342 static ssize_t mpc52xx_gpt_show_regs(struct device *dev,
 343                                      struct device_attribute *attr, char *buf)
 344 {
 345         struct mpc52xx_gpt_priv *gpt = dev_get_drvdata(dev);
 346         int i, len = 0;
 347         u32 __iomem *regs = (void __iomem *) gpt->regs;
 348
 349         for (i = 0; i < 4; i++)
 350                 len += sprintf(buf + len, "%.8x ", in_be32(regs + i));
 351         len += sprintf(buf + len, "\n");
 352
 353         return len;
 354 }
 355
 356 static struct device_attribute mpc52xx_gpt_attrib[] = {
 357         __ATTR(regs, S_IRUGO | S_IWUSR, mpc52xx_gpt_show_regs, NULL),
 358 };
 359
 360 static void mpc52xx_gpt_create_attribs(struct mpc52xx_gpt_priv *gpt)
 361 {
 362         int i, err = 0;
 363
 364         for (i = 0; i < ARRAY_SIZE(mpc52xx_gpt_attrib); i++) {
 365                 err = device_create_file(gpt->dev, &mpc52xx_gpt_attrib[i]);
 366                 if (err)
 367                         dev_err(gpt->dev, "error creating attribute %i\n", i);
 368         }
 369
 370 }
 371
 372 #else /* defined(CONFIG_SYSFS) */
 373 static void mpc52xx_gpt_create_attribs(struct mpc52xx_gpt_priv *) { return 0; }
 374 #endif /* defined(CONFIG_SYSFS) */
 375
 376 /* ---------------------------------------------------------------------
 377  * of_platform bus binding code
 378  */
 379 static int __devinit mpc52xx_gpt_probe(struct of_device *ofdev,
 380                                        const struct of_device_id *match)
 381 {
 382         struct mpc52xx_gpt_priv *gpt;
 383
 384         gpt = kzalloc(sizeof *gpt, GFP_KERNEL);
 385         if (!gpt)
 386                 return -ENOMEM;
 387
 388         spin_lock_init(&gpt->lock);
 389         gpt->dev = &ofdev->dev;
 390         gpt->regs = of_iomap(ofdev->node, 0);
 391         if (!gpt->regs) {
 392                 kfree(gpt);
 393                 return -ENOMEM;
 394         }
 395
 396         dev_set_drvdata(&ofdev->dev, gpt);
 397
 398         mpc52xx_gpt_create_attribs(gpt);
 399         mpc52xx_gpt_gpio_setup(gpt, ofdev->node);
 400         mpc52xx_gpt_irq_setup(gpt, ofdev->node);
 401
 402         return 0;
 403 }
 404
 405 static int mpc52xx_gpt_remove(struct of_device *ofdev)
 406 {
 407         return -EBUSY;
 408 }
 409
 410 static const struct of_device_id mpc52xx_gpt_match[] = {
 411         { .compatible = "fsl,mpc5200-gpt", },
 412
 413         /* Depreciated compatible values; don't use for new dts files */
 414         { .compatible = "fsl,mpc5200-gpt-gpio", },
 415         { .compatible = "mpc5200-gpt", },
 416         {}
 417 };
 418
 419 static struct of_platform_driver mpc52xx_gpt_driver = {
 420         .name = "mpc52xx-gpt",
 421         .match_table = mpc52xx_gpt_match,
 422         .probe = mpc52xx_gpt_probe,
 423         .remove = mpc52xx_gpt_remove,
 424 };
 425
 426 static int __init mpc52xx_gpt_init(void)
 427 {
 428         if (of_register_platform_driver(&mpc52xx_gpt_driver))
 429                 pr_err("error registering MPC52xx GPT driver\n");
 430
 431         return 0;
 432 }
 433
 434 /* Make sure GPIOs and IRQs get set up before anyone tries to use them */
 435 subsys_initcall(mpc52xx_gpt_init);