1 /*
2 * Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
3 * JZ4740 SoC ADC driver
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
9 *
10 * You should have received a copy of the GNU General Public License along
11 * with this program; if not, write to the Free Software Foundation, Inc.,
12 * 675 Mass Ave, Cambridge, MA 02139, USA.
13 *
14 * This driver synchronizes access to the JZ4740 ADC core between the
15 * JZ4740 battery and hwmon drivers.
16 */
17
18 #include <linux/err.h>
19 #include <linux/io.h>
20 #include <linux/irq.h>
21 #include <linux/interrupt.h>
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/platform_device.h>
25 #include <linux/slab.h>
26 #include <linux/spinlock.h>
27
28 #include <linux/clk.h>
29 #include <linux/mfd/core.h>
30
31 #include <linux/jz4740-adc.h>
32
33
34 #define JZ_REG_ADC_ENABLE 0x00
35 #define JZ_REG_ADC_CFG 0x04
36 #define JZ_REG_ADC_CTRL 0x08
37 #define JZ_REG_ADC_STATUS 0x0c
38
39 #define JZ_REG_ADC_TOUCHSCREEN_BASE 0x10
40 #define JZ_REG_ADC_BATTERY_BASE 0x1c
41 #define JZ_REG_ADC_HWMON_BASE 0x20
42
43 #define JZ_ADC_ENABLE_TOUCH BIT(2)
44 #define JZ_ADC_ENABLE_BATTERY BIT(1)
45 #define JZ_ADC_ENABLE_ADCIN BIT(0)
46
47 enum {
48 JZ_ADC_IRQ_ADCIN = 0,
49 JZ_ADC_IRQ_BATTERY,
50 JZ_ADC_IRQ_TOUCH,
51 JZ_ADC_IRQ_PENUP,
52 JZ_ADC_IRQ_PENDOWN,
53 };
54
55 struct jz4740_adc {
56 struct resource *mem;
57 void __iomem *base;
58
59 int irq;
60 struct irq_chip_generic *gc;
61
62 struct clk *clk;
63 atomic_t clk_ref;
64
65 spinlock_t lock;
66 };
67
jz4740_adc_irq_demux(struct irq_desc * desc)68 static void jz4740_adc_irq_demux(struct irq_desc *desc)
69 {
70 struct irq_chip_generic *gc = irq_desc_get_handler_data(desc);
71 uint8_t status;
72 unsigned int i;
73
74 status = readb(gc->reg_base + JZ_REG_ADC_STATUS);
75
76 for (i = 0; i < 5; ++i) {
77 if (status & BIT(i))
78 generic_handle_irq(gc->irq_base + i);
79 }
80 }
81
82
83 /* Refcounting for the ADC clock is done in here instead of in the clock
84 * framework, because it is the only clock which is shared between multiple
85 * devices and thus is the only clock which needs refcounting */
jz4740_adc_clk_enable(struct jz4740_adc * adc)86 static inline void jz4740_adc_clk_enable(struct jz4740_adc *adc)
87 {
88 if (atomic_inc_return(&adc->clk_ref) == 1)
89 clk_prepare_enable(adc->clk);
90 }
91
jz4740_adc_clk_disable(struct jz4740_adc * adc)92 static inline void jz4740_adc_clk_disable(struct jz4740_adc *adc)
93 {
94 if (atomic_dec_return(&adc->clk_ref) == 0)
95 clk_disable_unprepare(adc->clk);
96 }
97
jz4740_adc_set_enabled(struct jz4740_adc * adc,int engine,bool enabled)98 static inline void jz4740_adc_set_enabled(struct jz4740_adc *adc, int engine,
99 bool enabled)
100 {
101 unsigned long flags;
102 uint8_t val;
103
104 spin_lock_irqsave(&adc->lock, flags);
105
106 val = readb(adc->base + JZ_REG_ADC_ENABLE);
107 if (enabled)
108 val |= BIT(engine);
109 else
110 val &= ~BIT(engine);
111 writeb(val, adc->base + JZ_REG_ADC_ENABLE);
112
113 spin_unlock_irqrestore(&adc->lock, flags);
114 }
115
jz4740_adc_cell_enable(struct platform_device * pdev)116 static int jz4740_adc_cell_enable(struct platform_device *pdev)
117 {
118 struct jz4740_adc *adc = dev_get_drvdata(pdev->dev.parent);
119
120 jz4740_adc_clk_enable(adc);
121 jz4740_adc_set_enabled(adc, pdev->id, true);
122
123 return 0;
124 }
125
jz4740_adc_cell_disable(struct platform_device * pdev)126 static int jz4740_adc_cell_disable(struct platform_device *pdev)
127 {
128 struct jz4740_adc *adc = dev_get_drvdata(pdev->dev.parent);
129
130 jz4740_adc_set_enabled(adc, pdev->id, false);
131 jz4740_adc_clk_disable(adc);
132
133 return 0;
134 }
135
jz4740_adc_set_config(struct device * dev,uint32_t mask,uint32_t val)136 int jz4740_adc_set_config(struct device *dev, uint32_t mask, uint32_t val)
137 {
138 struct jz4740_adc *adc = dev_get_drvdata(dev);
139 unsigned long flags;
140 uint32_t cfg;
141
142 if (!adc)
143 return -ENODEV;
144
145 spin_lock_irqsave(&adc->lock, flags);
146
147 cfg = readl(adc->base + JZ_REG_ADC_CFG);
148
149 cfg &= ~mask;
150 cfg |= val;
151
152 writel(cfg, adc->base + JZ_REG_ADC_CFG);
153
154 spin_unlock_irqrestore(&adc->lock, flags);
155
156 return 0;
157 }
158 EXPORT_SYMBOL_GPL(jz4740_adc_set_config);
159
160 static struct resource jz4740_hwmon_resources[] = {
161 {
162 .start = JZ_ADC_IRQ_ADCIN,
163 .flags = IORESOURCE_IRQ,
164 },
165 {
166 .start = JZ_REG_ADC_HWMON_BASE,
167 .end = JZ_REG_ADC_HWMON_BASE + 3,
168 .flags = IORESOURCE_MEM,
169 },
170 };
171
172 static struct resource jz4740_battery_resources[] = {
173 {
174 .start = JZ_ADC_IRQ_BATTERY,
175 .flags = IORESOURCE_IRQ,
176 },
177 {
178 .start = JZ_REG_ADC_BATTERY_BASE,
179 .end = JZ_REG_ADC_BATTERY_BASE + 3,
180 .flags = IORESOURCE_MEM,
181 },
182 };
183
184 static const struct mfd_cell jz4740_adc_cells[] = {
185 {
186 .id = 0,
187 .name = "jz4740-hwmon",
188 .num_resources = ARRAY_SIZE(jz4740_hwmon_resources),
189 .resources = jz4740_hwmon_resources,
190
191 .enable = jz4740_adc_cell_enable,
192 .disable = jz4740_adc_cell_disable,
193 },
194 {
195 .id = 1,
196 .name = "jz4740-battery",
197 .num_resources = ARRAY_SIZE(jz4740_battery_resources),
198 .resources = jz4740_battery_resources,
199
200 .enable = jz4740_adc_cell_enable,
201 .disable = jz4740_adc_cell_disable,
202 },
203 };
204
jz4740_adc_probe(struct platform_device * pdev)205 static int jz4740_adc_probe(struct platform_device *pdev)
206 {
207 struct irq_chip_generic *gc;
208 struct irq_chip_type *ct;
209 struct jz4740_adc *adc;
210 struct resource *mem_base;
211 int ret;
212 int irq_base;
213
214 adc = devm_kzalloc(&pdev->dev, sizeof(*adc), GFP_KERNEL);
215 if (!adc)
216 return -ENOMEM;
217
218 adc->irq = platform_get_irq(pdev, 0);
219 if (adc->irq < 0) {
220 ret = adc->irq;
221 dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
222 return ret;
223 }
224
225 irq_base = platform_get_irq(pdev, 1);
226 if (irq_base < 0) {
227 dev_err(&pdev->dev, "Failed to get irq base: %d\n", irq_base);
228 return irq_base;
229 }
230
231 mem_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
232 if (!mem_base) {
233 dev_err(&pdev->dev, "Failed to get platform mmio resource\n");
234 return -ENOENT;
235 }
236
237 /* Only request the shared registers for the MFD driver */
238 adc->mem = request_mem_region(mem_base->start, JZ_REG_ADC_STATUS,
239 pdev->name);
240 if (!adc->mem) {
241 dev_err(&pdev->dev, "Failed to request mmio memory region\n");
242 return -EBUSY;
243 }
244
245 adc->base = ioremap_nocache(adc->mem->start, resource_size(adc->mem));
246 if (!adc->base) {
247 ret = -EBUSY;
248 dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
249 goto err_release_mem_region;
250 }
251
252 adc->clk = clk_get(&pdev->dev, "adc");
253 if (IS_ERR(adc->clk)) {
254 ret = PTR_ERR(adc->clk);
255 dev_err(&pdev->dev, "Failed to get clock: %d\n", ret);
256 goto err_iounmap;
257 }
258
259 spin_lock_init(&adc->lock);
260 atomic_set(&adc->clk_ref, 0);
261
262 platform_set_drvdata(pdev, adc);
263
264 gc = irq_alloc_generic_chip("INTC", 1, irq_base, adc->base,
265 handle_level_irq);
266
267 ct = gc->chip_types;
268 ct->regs.mask = JZ_REG_ADC_CTRL;
269 ct->regs.ack = JZ_REG_ADC_STATUS;
270 ct->chip.irq_mask = irq_gc_mask_set_bit;
271 ct->chip.irq_unmask = irq_gc_mask_clr_bit;
272 ct->chip.irq_ack = irq_gc_ack_set_bit;
273
274 irq_setup_generic_chip(gc, IRQ_MSK(5), IRQ_GC_INIT_MASK_CACHE, 0,
275 IRQ_NOPROBE | IRQ_LEVEL);
276
277 adc->gc = gc;
278
279 irq_set_chained_handler_and_data(adc->irq, jz4740_adc_irq_demux, gc);
280
281 writeb(0x00, adc->base + JZ_REG_ADC_ENABLE);
282 writeb(0xff, adc->base + JZ_REG_ADC_CTRL);
283
284 ret = mfd_add_devices(&pdev->dev, 0, jz4740_adc_cells,
285 ARRAY_SIZE(jz4740_adc_cells), mem_base,
286 irq_base, NULL);
287 if (ret < 0)
288 goto err_clk_put;
289
290 return 0;
291
292 err_clk_put:
293 clk_put(adc->clk);
294 err_iounmap:
295 iounmap(adc->base);
296 err_release_mem_region:
297 release_mem_region(adc->mem->start, resource_size(adc->mem));
298 return ret;
299 }
300
jz4740_adc_remove(struct platform_device * pdev)301 static int jz4740_adc_remove(struct platform_device *pdev)
302 {
303 struct jz4740_adc *adc = platform_get_drvdata(pdev);
304
305 mfd_remove_devices(&pdev->dev);
306
307 irq_remove_generic_chip(adc->gc, IRQ_MSK(5), IRQ_NOPROBE | IRQ_LEVEL, 0);
308 kfree(adc->gc);
309 irq_set_chained_handler_and_data(adc->irq, NULL, NULL);
310
311 iounmap(adc->base);
312 release_mem_region(adc->mem->start, resource_size(adc->mem));
313
314 clk_put(adc->clk);
315
316 return 0;
317 }
318
319 static struct platform_driver jz4740_adc_driver = {
320 .probe = jz4740_adc_probe,
321 .remove = jz4740_adc_remove,
322 .driver = {
323 .name = "jz4740-adc",
324 },
325 };
326
327 module_platform_driver(jz4740_adc_driver);
328
329 MODULE_DESCRIPTION("JZ4740 SoC ADC driver");
330 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
331 MODULE_LICENSE("GPL");
332 MODULE_ALIAS("platform:jz4740-adc");
333
