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 */
 47struct 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
 55static 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
 61static 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
 69static 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
 85static 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
112static 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
118static 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
139static 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
156static 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
214static struct of_device_id tz1090_pdc_gpio_of_match[] = {
215	{ .compatible = "img,tz1090-pdc-gpio" },
216	{ },
217};
218
219static 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
227static int __init tz1090_pdc_gpio_init(void)
228{
229	return platform_driver_register(&tz1090_pdc_gpio_driver);
230}
231subsys_initcall(tz1090_pdc_gpio_init);