drivers/gpio/gpio-tz1090-pdc.c

   1 /*
   2  * Toumaz Xenif TZ1090 PDC GPIO handling.
   3  *
   4  * Copyright (C) 2012-2013 Imagination Technologies Ltd.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/bitops.h>
  12 #include <linux/gpio.h>
  13 #include <linux/io.h>
  14 #include <linux/module.h>
  15 #include <linux/of_irq.h>
  16 #include <linux/pinctrl/consumer.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/slab.h>
  19 #include <linux/syscore_ops.h>
  20 #include <asm/global_lock.h>
  21
  22 /* Register offsets from SOC_GPIO_CONTROL0 */
  23 #define REG_SOC_GPIO_CONTROL0   0x00
  24 #define REG_SOC_GPIO_CONTROL1   0x04
  25 #define REG_SOC_GPIO_CONTROL2   0x08
  26 #define REG_SOC_GPIO_CONTROL3   0x0c
  27 #define REG_SOC_GPIO_STATUS     0x80
  28
  29 /* PDC GPIOs go after normal GPIOs */
  30 #define GPIO_PDC_BASE           90
  31 #define GPIO_PDC_NGPIO          7
  32
  33 /* Out of PDC gpios, only syswakes have irqs */
  34 #define GPIO_PDC_IRQ_FIRST      2
  35 #define GPIO_PDC_NIRQ           3
  36
  37 /**
  38  * struct tz1090_pdc_gpio - GPIO bank private data
  39  * @chip:       Generic GPIO chip for GPIO bank
  40  * @reg:        Base of registers, offset for this GPIO bank
  41  * @irq:        IRQ numbers for Syswake GPIOs
  42  *
  43  * This is the main private data for the PDC GPIO driver. It encapsulates a
  44  * gpio_chip, and the callbacks for the gpio_chip can access the private data
  45  * with the to_pdc() macro below.
  46  */
  47 struct tz1090_pdc_gpio {
  48         struct gpio_chip chip;
  49         void __iomem *reg;
  50         int irq[GPIO_PDC_NIRQ];
  51 };
  52
  53 /* Register accesses into the PDC MMIO area */
  54
  55 static inline void pdc_write(struct tz1090_pdc_gpio *priv, unsigned int reg_offs,
  56                       unsigned int data)
  57 {
  58         writel(data, priv->reg + reg_offs);
  59 }
  60
  61 static inline unsigned int pdc_read(struct tz1090_pdc_gpio *priv,
  62                              unsigned int reg_offs)
  63 {
  64         return readl(priv->reg + reg_offs);
  65 }
  66
  67 /* Generic GPIO interface */
  68
  69 static int tz1090_pdc_gpio_direction_input(struct gpio_chip *chip,
  70                                            unsigned int offset)
  71 {
  72         struct tz1090_pdc_gpio *priv = gpiochip_get_data(chip);
  73         u32 value;
  74         int lstat;
  75
  76         __global_lock2(lstat);
  77         value = pdc_read(priv, REG_SOC_GPIO_CONTROL1);
  78         value |= BIT(offset);
  79         pdc_write(priv, REG_SOC_GPIO_CONTROL1, value);
  80         __global_unlock2(lstat);
  81
  82         return 0;
  83 }
  84
  85 static int tz1090_pdc_gpio_direction_output(struct gpio_chip *chip,
  86                                             unsigned int offset,
  87                                             int output_value)
  88 {
  89         struct tz1090_pdc_gpio *priv = gpiochip_get_data(chip);
  90         u32 value;
  91         int lstat;
  92
  93         __global_lock2(lstat);
  94         /* EXT_POWER doesn't seem to have an output value bit */
  95         if (offset < 6) {
  96                 value = pdc_read(priv, REG_SOC_GPIO_CONTROL0);
  97                 if (output_value)
  98                         value |= BIT(offset);
  99                 else
 100                         value &= ~BIT(offset);
 101                 pdc_write(priv, REG_SOC_GPIO_CONTROL0, value);
 102         }
 103
 104         value = pdc_read(priv, REG_SOC_GPIO_CONTROL1);
 105         value &= ~BIT(offset);
 106         pdc_write(priv, REG_SOC_GPIO_CONTROL1, value);
 107         __global_unlock2(lstat);
 108
 109         return 0;
 110 }
 111
 112 static int tz1090_pdc_gpio_get(struct gpio_chip *chip, unsigned int offset)
 113 {
 114         struct tz1090_pdc_gpio *priv = gpiochip_get_data(chip);
 115         return !!(pdc_read(priv, REG_SOC_GPIO_STATUS) & BIT(offset));
 116 }
 117
 118 static void tz1090_pdc_gpio_set(struct gpio_chip *chip, unsigned int offset,
 119                                 int output_value)
 120 {
 121         struct tz1090_pdc_gpio *priv = gpiochip_get_data(chip);
 122         u32 value;
 123         int lstat;
 124
 125         /* EXT_POWER doesn't seem to have an output value bit */
 126         if (offset >= 6)
 127                 return;
 128
 129         __global_lock2(lstat);
 130         value = pdc_read(priv, REG_SOC_GPIO_CONTROL0);
 131         if (output_value)
 132                 value |= BIT(offset);
 133         else
 134                 value &= ~BIT(offset);
 135         pdc_write(priv, REG_SOC_GPIO_CONTROL0, value);
 136         __global_unlock2(lstat);
 137 }
 138
 139 static int tz1090_pdc_gpio_to_irq(struct gpio_chip *chip, unsigned int offset)
 140 {
 141         struct tz1090_pdc_gpio *priv = gpiochip_get_data(chip);
 142         unsigned int syswake = offset - GPIO_PDC_IRQ_FIRST;
 143         int irq;
 144
 145         /* only syswakes have irqs */
 146         if (syswake >= GPIO_PDC_NIRQ)
 147                 return -EINVAL;
 148
 149         irq = priv->irq[syswake];
 150         if (!irq)
 151                 return -EINVAL;
 152
 153         return irq;
 154 }
 155
 156 static int tz1090_pdc_gpio_probe(struct platform_device *pdev)
 157 {
 158         struct device_node *np = pdev->dev.of_node;
 159         struct resource *res_regs;
 160         struct tz1090_pdc_gpio *priv;
 161         unsigned int i;
 162
 163         if (!np) {
 164                 dev_err(&pdev->dev, "must be instantiated via devicetree\n");
 165                 return -ENOENT;
 166         }
 167
 168         res_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 169         if (!res_regs) {
 170                 dev_err(&pdev->dev, "cannot find registers resource\n");
 171                 return -ENOENT;
 172         }
 173
 174         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 175         if (!priv) {
 176                 dev_err(&pdev->dev, "unable to allocate driver data\n");
 177                 return -ENOMEM;
 178         }
 179
 180         /* Ioremap the registers */
 181         priv->reg = devm_ioremap(&pdev->dev, res_regs->start,
 182                                  resource_size(res_regs));
 183         if (!priv->reg) {
 184                 dev_err(&pdev->dev, "unable to ioremap registers\n");
 185                 return -ENOMEM;
 186         }
 187
 188         /* Set up GPIO chip */
 189         priv->chip.label                = "tz1090-pdc-gpio";
 190         priv->chip.parent               = &pdev->dev;
 191         priv->chip.direction_input      = tz1090_pdc_gpio_direction_input;
 192         priv->chip.direction_output     = tz1090_pdc_gpio_direction_output;
 193         priv->chip.get                  = tz1090_pdc_gpio_get;
 194         priv->chip.set                  = tz1090_pdc_gpio_set;
 195         priv->chip.free                 = gpiochip_generic_free;
 196         priv->chip.request              = gpiochip_generic_request;
 197         priv->chip.to_irq               = tz1090_pdc_gpio_to_irq;
 198         priv->chip.of_node              = np;
 199
 200         /* GPIO numbering */
 201         priv->chip.base                 = GPIO_PDC_BASE;
 202         priv->chip.ngpio                = GPIO_PDC_NGPIO;
 203
 204         /* Map the syswake irqs */
 205         for (i = 0; i < GPIO_PDC_NIRQ; ++i)
 206                 priv->irq[i] = irq_of_parse_and_map(np, i);
 207
 208         /* Add the GPIO bank */
 209         gpiochip_add_data(&priv->chip, priv);
 210
 211         return 0;
 212 }
 213
 214 static struct of_device_id tz1090_pdc_gpio_of_match[] = {
 215         { .compatible = "img,tz1090-pdc-gpio" },
 216         { },
 217 };
 218
 219 static struct platform_driver tz1090_pdc_gpio_driver = {
 220         .driver = {
 221                 .name           = "tz1090-pdc-gpio",
 222                 .of_match_table = tz1090_pdc_gpio_of_match,
 223         },
 224         .probe          = tz1090_pdc_gpio_probe,
 225 };
 226
 227 static int __init tz1090_pdc_gpio_init(void)
 228 {
 229         return platform_driver_register(&tz1090_pdc_gpio_driver);
 230 }
 231 subsys_initcall(tz1090_pdc_gpio_init);