drivers/gpio/altera_pio.c

   1 /*
   2  * Copyright (C) 2015  Thomas Chou <thomas@wytron.com.tw>
   3  * Copyright (C) 2011  Missing Link Electronics
   4  *                     Joachim Foerster <joachim@missinglinkelectronics.com>
   5  *
   6  * SPDX-License-Identifier:     GPL-2.0+
   7  */
   8 #include <common.h>
   9 #include <dm.h>
  10 #include <errno.h>
  11 #include <malloc.h>
  12 #include <fdtdec.h>
  13 #include <asm/io.h>
  14 #include <asm/gpio.h>
  15
  16 DECLARE_GLOBAL_DATA_PTR;
  17
  18 struct altera_pio_regs {
  19         u32     data;                   /* Data register */
  20         u32     direction;              /* Direction register */
  21 };
  22
  23 struct altera_pio_platdata {
  24         struct altera_pio_regs *regs;
  25         int gpio_count;
  26         const char *bank_name;
  27 };
  28
  29 static int altera_pio_direction_input(struct udevice *dev, unsigned pin)
  30 {
  31         struct altera_pio_platdata *plat = dev_get_platdata(dev);
  32         struct altera_pio_regs *const regs = plat->regs;
  33
  34         clrbits_le32(&regs->direction, 1 << pin);
  35
  36         return 0;
  37 }
  38
  39 static int altera_pio_direction_output(struct udevice *dev, unsigned pin,
  40                                      int val)
  41 {
  42         struct altera_pio_platdata *plat = dev_get_platdata(dev);
  43         struct altera_pio_regs *const regs = plat->regs;
  44
  45         if (val)
  46                 setbits_le32(&regs->data, 1 << pin);
  47         else
  48                 clrbits_le32(&regs->data, 1 << pin);
  49         /* change the data first, then the direction. to avoid glitch */
  50         setbits_le32(&regs->direction, 1 << pin);
  51
  52         return 0;
  53 }
  54
  55 static int altera_pio_get_value(struct udevice *dev, unsigned pin)
  56 {
  57         struct altera_pio_platdata *plat = dev_get_platdata(dev);
  58         struct altera_pio_regs *const regs = plat->regs;
  59
  60         return readl(&regs->data) & (1 << pin);
  61 }
  62
  63
  64 static int altera_pio_set_value(struct udevice *dev, unsigned pin, int val)
  65 {
  66         struct altera_pio_platdata *plat = dev_get_platdata(dev);
  67         struct altera_pio_regs *const regs = plat->regs;
  68
  69         if (val)
  70                 setbits_le32(&regs->data, 1 << pin);
  71         else
  72                 clrbits_le32(&regs->data, 1 << pin);
  73
  74         return 0;
  75 }
  76
  77 static int altera_pio_probe(struct udevice *dev)
  78 {
  79         struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
  80         struct altera_pio_platdata *plat = dev_get_platdata(dev);
  81
  82         uc_priv->gpio_count = plat->gpio_count;
  83         uc_priv->bank_name = plat->bank_name;
  84
  85         return 0;
  86 }
  87
  88 static int altera_pio_ofdata_to_platdata(struct udevice *dev)
  89 {
  90         struct altera_pio_platdata *plat = dev_get_platdata(dev);
  91
  92         plat->regs = map_physmem(dev_get_addr(dev),
  93                                  sizeof(struct altera_pio_regs),
  94                                  MAP_NOCACHE);
  95         plat->gpio_count = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
  96                 "altr,gpio-bank-width", 32);
  97         plat->bank_name = fdt_getprop(gd->fdt_blob, dev->of_offset,
  98                 "gpio-bank-name", NULL);
  99
 100         return 0;
 101 }
 102
 103 static const struct dm_gpio_ops altera_pio_ops = {
 104         .direction_input        = altera_pio_direction_input,
 105         .direction_output       = altera_pio_direction_output,
 106         .get_value              = altera_pio_get_value,
 107         .set_value              = altera_pio_set_value,
 108 };
 109
 110 static const struct udevice_id altera_pio_ids[] = {
 111         { .compatible = "altr,pio-1.0" },
 112         { }
 113 };
 114
 115 U_BOOT_DRIVER(altera_pio) = {
 116         .name           = "altera_pio",
 117         .id             = UCLASS_GPIO,
 118         .of_match       = altera_pio_ids,
 119         .ops            = &altera_pio_ops,
 120         .ofdata_to_platdata = altera_pio_ofdata_to_platdata,
 121         .platdata_auto_alloc_size = sizeof(struct altera_pio_platdata),
 122         .probe          = altera_pio_probe,
 123 };