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 #define to_pdc(c)       container_of(c, struct tz1090_pdc_gpio, chip)
  53
  54 /* Register accesses into the PDC MMIO area */
  55
  56 static inline void pdc_write(struct tz1090_pdc_gpio *priv, unsigned int reg_offs,
  57                       unsigned int data)
  58 {
  59         writel(data, priv->reg + reg_offs);
  60 }
  61
  62 static inline unsigned int pdc_read(struct tz1090_pdc_gpio *priv,
  63                              unsigned int reg_offs)
  64 {
  65         return readl(priv->reg + reg_offs);
  66 }
  67
  68 /* Generic GPIO interface */
  69
  70 static int tz1090_pdc_gpio_direction_input(struct gpio_chip *chip,
  71                                            unsigned int offset)
  72 {
  73         struct tz1090_pdc_gpio *priv = to_pdc(chip);
  74         u32 value;
  75         int lstat;
  76
  77         __global_lock2(lstat);
  78         value = pdc_read(priv, REG_SOC_GPIO_CONTROL1);
  79         value |= BIT(offset);
  80         pdc_write(priv, REG_SOC_GPIO_CONTROL1, value);
  81         __global_unlock2(lstat);
  82
  83         return 0;
  84 }
  85
  86 static int tz1090_pdc_gpio_direction_output(struct gpio_chip *chip,
  87                                             unsigned int offset,
  88                                             int output_value)
  89 {
  90         struct tz1090_pdc_gpio *priv = to_pdc(chip);
  91         u32 value;
  92         int lstat;
  93
  94         __global_lock2(lstat);
  95         /* EXT_POWER doesn't seem to have an output value bit */
  96         if (offset < 6) {
  97                 value = pdc_read(priv, REG_SOC_GPIO_CONTROL0);
  98                 if (output_value)
  99                         value |= BIT(offset);
 100                 else
 101                         value &= ~BIT(offset);
 102                 pdc_write(priv, REG_SOC_GPIO_CONTROL0, value);
 103         }
 104
 105         value = pdc_read(priv, REG_SOC_GPIO_CONTROL1);
 106         value &= ~BIT(offset);
 107         pdc_write(priv, REG_SOC_GPIO_CONTROL1, value);
 108         __global_unlock2(lstat);
 109
 110         return 0;
 111 }
 112
 113 static int tz1090_pdc_gpio_get(struct gpio_chip *chip, unsigned int offset)
 114 {
 115         struct tz1090_pdc_gpio *priv = to_pdc(chip);
 116         return pdc_read(priv, REG_SOC_GPIO_STATUS) & BIT(offset);
 117 }
 118
 119 static void tz1090_pdc_gpio_set(struct gpio_chip *chip, unsigned int offset,
 120                                 int output_value)
 121 {
 122         struct tz1090_pdc_gpio *priv = to_pdc(chip);
 123         u32 value;
 124         int lstat;
 125
 126         /* EXT_POWER doesn't seem to have an output value bit */
 127         if (offset >= 6)
 128                 return;
 129
 130         __global_lock2(lstat);
 131         value = pdc_read(priv, REG_SOC_GPIO_CONTROL0);
 132         if (output_value)
 133                 value |= BIT(offset);
 134         else
 135                 value &= ~BIT(offset);
 136         pdc_write(priv, REG_SOC_GPIO_CONTROL0, value);
 137         __global_unlock2(lstat);
 138 }
 139
 140 static int tz1090_pdc_gpio_request(struct gpio_chip *chip, unsigned int offset)
 141 {
 142         return pinctrl_request_gpio(chip->base + offset);
 143 }
 144
 145 static void tz1090_pdc_gpio_free(struct gpio_chip *chip, unsigned int offset)
 146 {
 147         pinctrl_free_gpio(chip->base + offset);
 148 }
 149
 150 static int tz1090_pdc_gpio_to_irq(struct gpio_chip *chip, unsigned int offset)
 151 {
 152         struct tz1090_pdc_gpio *priv = to_pdc(chip);
 153         unsigned int syswake = offset - GPIO_PDC_IRQ_FIRST;
 154         int irq;
 155
 156         /* only syswakes have irqs */
 157         if (syswake >= GPIO_PDC_NIRQ)
 158                 return -EINVAL;
 159
 160         irq = priv->irq[syswake];
 161         if (!irq)
 162                 return -EINVAL;
 163
 164         return irq;
 165 }
 166
 167 static int tz1090_pdc_gpio_probe(struct platform_device *pdev)
 168 {
 169         struct device_node *np = pdev->dev.of_node;
 170         struct resource *res_regs;
 171         struct tz1090_pdc_gpio *priv;
 172         unsigned int i;
 173
 174         if (!np) {
 175                 dev_err(&pdev->dev, "must be instantiated via devicetree\n");
 176                 return -ENOENT;
 177         }
 178
 179         res_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 180         if (!res_regs) {
 181                 dev_err(&pdev->dev, "cannot find registers resource\n");
 182                 return -ENOENT;
 183         }
 184
 185         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 186         if (!priv) {
 187                 dev_err(&pdev->dev, "unable to allocate driver data\n");
 188                 return -ENOMEM;
 189         }
 190
 191         /* Ioremap the registers */
 192         priv->reg = devm_ioremap(&pdev->dev, res_regs->start,
 193                                  resource_size(res_regs));
 194         if (!priv->reg) {
 195                 dev_err(&pdev->dev, "unable to ioremap registers\n");
 196                 return -ENOMEM;
 197         }
 198
 199         /* Set up GPIO chip */
 200         priv->chip.label                = "tz1090-pdc-gpio";
 201         priv->chip.dev                  = &pdev->dev;
 202         priv->chip.direction_input      = tz1090_pdc_gpio_direction_input;
 203         priv->chip.direction_output     = tz1090_pdc_gpio_direction_output;
 204         priv->chip.get                  = tz1090_pdc_gpio_get;
 205         priv->chip.set                  = tz1090_pdc_gpio_set;
 206         priv->chip.free                 = tz1090_pdc_gpio_free;
 207         priv->chip.request              = tz1090_pdc_gpio_request;
 208         priv->chip.to_irq               = tz1090_pdc_gpio_to_irq;
 209         priv->chip.of_node              = np;
 210
 211         /* GPIO numbering */
 212         priv->chip.base                 = GPIO_PDC_BASE;
 213         priv->chip.ngpio                = GPIO_PDC_NGPIO;
 214
 215         /* Map the syswake irqs */
 216         for (i = 0; i < GPIO_PDC_NIRQ; ++i)
 217                 priv->irq[i] = irq_of_parse_and_map(np, i);
 218
 219         /* Add the GPIO bank */
 220         gpiochip_add(&priv->chip);
 221
 222         return 0;
 223 }
 224
 225 static struct of_device_id tz1090_pdc_gpio_of_match[] = {
 226         { .compatible = "img,tz1090-pdc-gpio" },
 227         { },
 228 };
 229
 230 static struct platform_driver tz1090_pdc_gpio_driver = {
 231         .driver = {
 232                 .name           = "tz1090-pdc-gpio",
 233                 .of_match_table = tz1090_pdc_gpio_of_match,
 234         },
 235         .probe          = tz1090_pdc_gpio_probe,
 236 };
 237
 238 static int __init tz1090_pdc_gpio_init(void)
 239 {
 240         return platform_driver_register(&tz1090_pdc_gpio_driver);
 241 }
 242 subsys_initcall(tz1090_pdc_gpio_init);