drivers/gpio/altera_pio.c

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