Merge tag 'for-4.20-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave...
[linux-2.6-block.git] / drivers / gpio / gpio-ftgpio010.c
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b2441318 1// SPDX-License-Identifier: GPL-2.0
49cec4d8 2/*
9d3a15aa 3 * Faraday Technolog FTGPIO010 gpiochip and interrupt routines
49cec4d8
LW
4 * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
5 *
6 * Based on arch/arm/mach-gemini/gpio.c:
7 * Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
8 *
9 * Based on plat-mxc/gpio.c:
10 * MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de>
11 * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
12 */
13#include <linux/gpio/driver.h>
14#include <linux/io.h>
15#include <linux/interrupt.h>
16#include <linux/platform_device.h>
49cec4d8 17#include <linux/bitops.h>
da02d794 18#include <linux/clk.h>
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19
20/* GPIO registers definition */
21#define GPIO_DATA_OUT 0x00
22#define GPIO_DATA_IN 0x04
23#define GPIO_DIR 0x08
69a87f29 24#define GPIO_BYPASS_IN 0x0C
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25#define GPIO_DATA_SET 0x10
26#define GPIO_DATA_CLR 0x14
27#define GPIO_PULL_EN 0x18
28#define GPIO_PULL_TYPE 0x1C
29#define GPIO_INT_EN 0x20
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30#define GPIO_INT_STAT_RAW 0x24
31#define GPIO_INT_STAT_MASKED 0x28
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32#define GPIO_INT_MASK 0x2C
33#define GPIO_INT_CLR 0x30
34#define GPIO_INT_TYPE 0x34
35#define GPIO_INT_BOTH_EDGE 0x38
36#define GPIO_INT_LEVEL 0x3C
37#define GPIO_DEBOUNCE_EN 0x40
38#define GPIO_DEBOUNCE_PRESCALE 0x44
39
40/**
9d3a15aa 41 * struct ftgpio_gpio - Gemini GPIO state container
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42 * @dev: containing device for this instance
43 * @gc: gpiochip for this instance
da02d794
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44 * @base: remapped I/O-memory base
45 * @clk: silicon clock
49cec4d8 46 */
9d3a15aa 47struct ftgpio_gpio {
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48 struct device *dev;
49 struct gpio_chip gc;
50 void __iomem *base;
da02d794 51 struct clk *clk;
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52};
53
9d3a15aa 54static void ftgpio_gpio_ack_irq(struct irq_data *d)
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55{
56 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
9d3a15aa 57 struct ftgpio_gpio *g = gpiochip_get_data(gc);
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58
59 writel(BIT(irqd_to_hwirq(d)), g->base + GPIO_INT_CLR);
60}
61
9d3a15aa 62static void ftgpio_gpio_mask_irq(struct irq_data *d)
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63{
64 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
9d3a15aa 65 struct ftgpio_gpio *g = gpiochip_get_data(gc);
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66 u32 val;
67
68 val = readl(g->base + GPIO_INT_EN);
69 val &= ~BIT(irqd_to_hwirq(d));
70 writel(val, g->base + GPIO_INT_EN);
71}
72
9d3a15aa 73static void ftgpio_gpio_unmask_irq(struct irq_data *d)
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74{
75 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
9d3a15aa 76 struct ftgpio_gpio *g = gpiochip_get_data(gc);
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77 u32 val;
78
79 val = readl(g->base + GPIO_INT_EN);
80 val |= BIT(irqd_to_hwirq(d));
81 writel(val, g->base + GPIO_INT_EN);
82}
83
9d3a15aa 84static int ftgpio_gpio_set_irq_type(struct irq_data *d, unsigned int type)
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85{
86 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
9d3a15aa 87 struct ftgpio_gpio *g = gpiochip_get_data(gc);
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88 u32 mask = BIT(irqd_to_hwirq(d));
89 u32 reg_both, reg_level, reg_type;
90
91 reg_type = readl(g->base + GPIO_INT_TYPE);
92 reg_level = readl(g->base + GPIO_INT_LEVEL);
93 reg_both = readl(g->base + GPIO_INT_BOTH_EDGE);
94
95 switch (type) {
96 case IRQ_TYPE_EDGE_BOTH:
97 irq_set_handler_locked(d, handle_edge_irq);
98 reg_type &= ~mask;
99 reg_both |= mask;
100 break;
101 case IRQ_TYPE_EDGE_RISING:
102 irq_set_handler_locked(d, handle_edge_irq);
103 reg_type &= ~mask;
104 reg_both &= ~mask;
105 reg_level &= ~mask;
106 break;
107 case IRQ_TYPE_EDGE_FALLING:
108 irq_set_handler_locked(d, handle_edge_irq);
109 reg_type &= ~mask;
110 reg_both &= ~mask;
111 reg_level |= mask;
112 break;
113 case IRQ_TYPE_LEVEL_HIGH:
114 irq_set_handler_locked(d, handle_level_irq);
115 reg_type |= mask;
116 reg_level &= ~mask;
117 break;
118 case IRQ_TYPE_LEVEL_LOW:
119 irq_set_handler_locked(d, handle_level_irq);
120 reg_type |= mask;
121 reg_level |= mask;
122 break;
123 default:
124 irq_set_handler_locked(d, handle_bad_irq);
125 return -EINVAL;
126 }
127
128 writel(reg_type, g->base + GPIO_INT_TYPE);
129 writel(reg_level, g->base + GPIO_INT_LEVEL);
130 writel(reg_both, g->base + GPIO_INT_BOTH_EDGE);
131
9d3a15aa 132 ftgpio_gpio_ack_irq(d);
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133
134 return 0;
135}
136
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137static struct irq_chip ftgpio_gpio_irqchip = {
138 .name = "FTGPIO010",
139 .irq_ack = ftgpio_gpio_ack_irq,
140 .irq_mask = ftgpio_gpio_mask_irq,
141 .irq_unmask = ftgpio_gpio_unmask_irq,
142 .irq_set_type = ftgpio_gpio_set_irq_type,
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143};
144
9d3a15aa 145static void ftgpio_gpio_irq_handler(struct irq_desc *desc)
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146{
147 struct gpio_chip *gc = irq_desc_get_handler_data(desc);
9d3a15aa 148 struct ftgpio_gpio *g = gpiochip_get_data(gc);
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149 struct irq_chip *irqchip = irq_desc_get_chip(desc);
150 int offset;
151 unsigned long stat;
152
153 chained_irq_enter(irqchip, desc);
154
69a87f29 155 stat = readl(g->base + GPIO_INT_STAT_RAW);
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156 if (stat)
157 for_each_set_bit(offset, &stat, gc->ngpio)
f0fbe7bc 158 generic_handle_irq(irq_find_mapping(gc->irq.domain,
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159 offset));
160
161 chained_irq_exit(irqchip, desc);
162}
163
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164static int ftgpio_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
165 unsigned long config)
166{
167 enum pin_config_param param = pinconf_to_config_param(config);
168 u32 arg = pinconf_to_config_argument(config);
169 struct ftgpio_gpio *g = gpiochip_get_data(gc);
170 unsigned long pclk_freq;
171 u32 deb_div;
172 u32 val;
173
174 if (param != PIN_CONFIG_INPUT_DEBOUNCE)
175 return -ENOTSUPP;
176
177 /*
178 * Debounce only works if interrupts are enabled. The manual
179 * states that if PCLK is 66 MHz, and this is set to 0x7D0, then
180 * PCLK is divided down to 33 kHz for the debounce timer. 0x7D0 is
181 * 2000 decimal, so what they mean is simply that the PCLK is
182 * divided by this value.
183 *
184 * As we get a debounce setting in microseconds, we calculate the
185 * desired period time and see if we can get a suitable debounce
186 * time.
187 */
188 pclk_freq = clk_get_rate(g->clk);
189 deb_div = DIV_ROUND_CLOSEST(pclk_freq, arg);
190
191 /* This register is only 24 bits wide */
192 if (deb_div > (1 << 24))
193 return -ENOTSUPP;
194
195 dev_dbg(g->dev, "prescale divisor: %08x, resulting frequency %lu Hz\n",
196 deb_div, (pclk_freq/deb_div));
197
198 val = readl(g->base + GPIO_DEBOUNCE_PRESCALE);
199 if (val == deb_div) {
200 /*
201 * The debounce timer happens to already be set to the
202 * desireable value, what a coincidence! We can just enable
203 * debounce on this GPIO line and return. This happens more
204 * often than you think, for example when all GPIO keys
205 * on a system are requesting the same debounce interval.
206 */
207 val = readl(g->base + GPIO_DEBOUNCE_EN);
208 val |= BIT(offset);
209 writel(val, g->base + GPIO_DEBOUNCE_EN);
210 return 0;
211 }
212
213 val = readl(g->base + GPIO_DEBOUNCE_EN);
214 if (val) {
215 /*
216 * Oh no! Someone is already using the debounce with
217 * another setting than what we need. Bummer.
218 */
219 return -ENOTSUPP;
220 }
221
222 /* First come, first serve */
223 writel(deb_div, g->base + GPIO_DEBOUNCE_PRESCALE);
224 /* Enable debounce */
225 val |= BIT(offset);
226 writel(val, g->base + GPIO_DEBOUNCE_EN);
227
228 return 0;
229}
230
9d3a15aa 231static int ftgpio_gpio_probe(struct platform_device *pdev)
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232{
233 struct device *dev = &pdev->dev;
234 struct resource *res;
9d3a15aa 235 struct ftgpio_gpio *g;
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236 int irq;
237 int ret;
238
239 g = devm_kzalloc(dev, sizeof(*g), GFP_KERNEL);
240 if (!g)
241 return -ENOMEM;
242
243 g->dev = dev;
244
245 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
246 g->base = devm_ioremap_resource(dev, res);
247 if (IS_ERR(g->base))
248 return PTR_ERR(g->base);
249
250 irq = platform_get_irq(pdev, 0);
4070a534
AY
251 if (irq <= 0)
252 return irq ? irq : -EINVAL;
49cec4d8 253
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254 g->clk = devm_clk_get(dev, NULL);
255 if (!IS_ERR(g->clk)) {
256 ret = clk_prepare_enable(g->clk);
257 if (ret)
258 return ret;
259 } else if (PTR_ERR(g->clk) == -EPROBE_DEFER) {
260 /*
261 * Percolate deferrals, for anything else,
262 * just live without the clocking.
263 */
264 return PTR_ERR(g->clk);
265 }
266
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267 ret = bgpio_init(&g->gc, dev, 4,
268 g->base + GPIO_DATA_IN,
269 g->base + GPIO_DATA_SET,
270 g->base + GPIO_DATA_CLR,
271 g->base + GPIO_DIR,
272 NULL,
273 0);
274 if (ret) {
275 dev_err(dev, "unable to init generic GPIO\n");
da02d794 276 goto dis_clk;
49cec4d8 277 }
9d3a15aa 278 g->gc.label = "FTGPIO010";
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279 g->gc.base = -1;
280 g->gc.parent = dev;
281 g->gc.owner = THIS_MODULE;
282 /* ngpio is set by bgpio_init() */
283
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284 /* We need a silicon clock to do debounce */
285 if (!IS_ERR(g->clk))
286 g->gc.set_config = ftgpio_gpio_set_config;
287
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288 ret = devm_gpiochip_add_data(dev, &g->gc, g);
289 if (ret)
da02d794 290 goto dis_clk;
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291
292 /* Disable, unmask and clear all interrupts */
293 writel(0x0, g->base + GPIO_INT_EN);
294 writel(0x0, g->base + GPIO_INT_MASK);
295 writel(~0x0, g->base + GPIO_INT_CLR);
296
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297 /* Clear any use of debounce */
298 writel(0x0, g->base + GPIO_DEBOUNCE_EN);
299
9d3a15aa 300 ret = gpiochip_irqchip_add(&g->gc, &ftgpio_gpio_irqchip,
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301 0, handle_bad_irq,
302 IRQ_TYPE_NONE);
303 if (ret) {
304 dev_info(dev, "could not add irqchip\n");
da02d794 305 goto dis_clk;
49cec4d8 306 }
9d3a15aa
LW
307 gpiochip_set_chained_irqchip(&g->gc, &ftgpio_gpio_irqchip,
308 irq, ftgpio_gpio_irq_handler);
49cec4d8 309
da02d794 310 platform_set_drvdata(pdev, g);
9d3a15aa 311 dev_info(dev, "FTGPIO010 @%p registered\n", g->base);
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312
313 return 0;
da02d794
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314
315dis_clk:
316 if (!IS_ERR(g->clk))
317 clk_disable_unprepare(g->clk);
318 return ret;
319}
320
321static int ftgpio_gpio_remove(struct platform_device *pdev)
322{
323 struct ftgpio_gpio *g = platform_get_drvdata(pdev);
324
325 if (!IS_ERR(g->clk))
326 clk_disable_unprepare(g->clk);
327 return 0;
49cec4d8
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328}
329
9d3a15aa 330static const struct of_device_id ftgpio_gpio_of_match[] = {
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331 {
332 .compatible = "cortina,gemini-gpio",
333 },
9d3a15aa
LW
334 {
335 .compatible = "moxa,moxart-gpio",
336 },
337 {
338 .compatible = "faraday,ftgpio010",
339 },
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340 {},
341};
342
9d3a15aa 343static struct platform_driver ftgpio_gpio_driver = {
49cec4d8 344 .driver = {
9d3a15aa
LW
345 .name = "ftgpio010-gpio",
346 .of_match_table = of_match_ptr(ftgpio_gpio_of_match),
49cec4d8 347 },
da02d794
LW
348 .probe = ftgpio_gpio_probe,
349 .remove = ftgpio_gpio_remove,
49cec4d8 350};
9d3a15aa 351builtin_platform_driver(ftgpio_gpio_driver);