8ca3bf023fb25a2e70a5d78dd8426e7a3cfa6109
[~shefty/rdma-dev.git] / drivers / mfd / ti_am335x_tscadc.c
1 /*
2  * TI Touch Screen / ADC MFD driver
3  *
4  * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License as
8  * published by the Free Software Foundation version 2.
9  *
10  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
11  * kind, whether express or implied; without even the implied warranty
12  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  */
15
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/slab.h>
19 #include <linux/err.h>
20 #include <linux/io.h>
21 #include <linux/clk.h>
22 #include <linux/regmap.h>
23 #include <linux/mfd/core.h>
24 #include <linux/pm_runtime.h>
25
26 #include <linux/mfd/ti_am335x_tscadc.h>
27 #include <linux/input/ti_am335x_tsc.h>
28 #include <linux/platform_data/ti_am335x_adc.h>
29
30 static unsigned int tscadc_readl(struct ti_tscadc_dev *tsadc, unsigned int reg)
31 {
32         unsigned int val;
33
34         regmap_read(tsadc->regmap_tscadc, reg, &val);
35         return val;
36 }
37
38 static void tscadc_writel(struct ti_tscadc_dev *tsadc, unsigned int reg,
39                                         unsigned int val)
40 {
41         regmap_write(tsadc->regmap_tscadc, reg, val);
42 }
43
44 static const struct regmap_config tscadc_regmap_config = {
45         .name = "ti_tscadc",
46         .reg_bits = 32,
47         .reg_stride = 4,
48         .val_bits = 32,
49 };
50
51 static void tscadc_idle_config(struct ti_tscadc_dev *config)
52 {
53         unsigned int idleconfig;
54
55         idleconfig = STEPCONFIG_YNN | STEPCONFIG_INM_ADCREFM |
56                         STEPCONFIG_INP_ADCREFM | STEPCONFIG_YPN;
57
58         tscadc_writel(config, REG_IDLECONFIG, idleconfig);
59 }
60
61 static  int __devinit ti_tscadc_probe(struct platform_device *pdev)
62 {
63         struct ti_tscadc_dev    *tscadc;
64         struct resource         *res;
65         struct clk              *clk;
66         struct mfd_tscadc_board *pdata = pdev->dev.platform_data;
67         struct mfd_cell         *cell;
68         int                     err, ctrl;
69         int                     clk_value, clock_rate;
70         int                     tsc_wires, adc_channels = 0, total_channels;
71
72         if (!pdata) {
73                 dev_err(&pdev->dev, "Could not find platform data\n");
74                 return -EINVAL;
75         }
76
77         if (pdata->adc_init)
78                 adc_channels = pdata->adc_init->adc_channels;
79
80         tsc_wires = pdata->tsc_init->wires;
81         total_channels = tsc_wires + adc_channels;
82
83         if (total_channels > 8) {
84                 dev_err(&pdev->dev, "Number of i/p channels more than 8\n");
85                 return -EINVAL;
86         }
87
88         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
89         if (!res) {
90                 dev_err(&pdev->dev, "no memory resource defined.\n");
91                 return -EINVAL;
92         }
93
94         /* Allocate memory for device */
95         tscadc = devm_kzalloc(&pdev->dev,
96                         sizeof(struct ti_tscadc_dev), GFP_KERNEL);
97         if (!tscadc) {
98                 dev_err(&pdev->dev, "failed to allocate memory.\n");
99                 return -ENOMEM;
100         }
101         tscadc->dev = &pdev->dev;
102
103         err = platform_get_irq(pdev, 0);
104         if (err < 0) {
105                 dev_err(&pdev->dev, "no irq ID is specified.\n");
106                 goto ret;
107         } else
108                 tscadc->irq = err;
109
110         res = devm_request_mem_region(&pdev->dev,
111                         res->start, resource_size(res), pdev->name);
112         if (!res) {
113                 dev_err(&pdev->dev, "failed to reserve registers.\n");
114                 return -EBUSY;
115         }
116
117         tscadc->tscadc_base = devm_ioremap(&pdev->dev,
118                         res->start, resource_size(res));
119         if (!tscadc->tscadc_base) {
120                 dev_err(&pdev->dev, "failed to map registers.\n");
121                 return -ENOMEM;
122         }
123
124         tscadc->regmap_tscadc = devm_regmap_init_mmio(&pdev->dev,
125                         tscadc->tscadc_base, &tscadc_regmap_config);
126         if (IS_ERR(tscadc->regmap_tscadc)) {
127                 dev_err(&pdev->dev, "regmap init failed\n");
128                 err = PTR_ERR(tscadc->regmap_tscadc);
129                 goto ret;
130         }
131
132         pm_runtime_enable(&pdev->dev);
133         pm_runtime_get_sync(&pdev->dev);
134
135         /*
136          * The TSC_ADC_Subsystem has 2 clock domains
137          * OCP_CLK and ADC_CLK.
138          * The ADC clock is expected to run at target of 3MHz,
139          * and expected to capture 12-bit data at a rate of 200 KSPS.
140          * The TSC_ADC_SS controller design assumes the OCP clock is
141          * at least 6x faster than the ADC clock.
142          */
143         clk = clk_get(&pdev->dev, "adc_tsc_fck");
144         if (IS_ERR(clk)) {
145                 dev_err(&pdev->dev, "failed to get TSC fck\n");
146                 err = PTR_ERR(clk);
147                 goto err_disable_clk;
148         }
149         clock_rate = clk_get_rate(clk);
150         clk_put(clk);
151         clk_value = clock_rate / ADC_CLK;
152         if (clk_value < MAX_CLK_DIV) {
153                 dev_err(&pdev->dev, "clock input less than min clock requirement\n");
154                 err = -EINVAL;
155                 goto err_disable_clk;
156         }
157         /* TSCADC_CLKDIV needs to be configured to the value minus 1 */
158         clk_value = clk_value - 1;
159         tscadc_writel(tscadc, REG_CLKDIV, clk_value);
160
161         /* Set the control register bits */
162         ctrl = CNTRLREG_STEPCONFIGWRT |
163                         CNTRLREG_TSCENB |
164                         CNTRLREG_STEPID |
165                         CNTRLREG_4WIRE;
166         tscadc_writel(tscadc, REG_CTRL, ctrl);
167
168         /* Set register bits for Idle Config Mode */
169         tscadc_idle_config(tscadc);
170
171         /* Enable the TSC module enable bit */
172         ctrl = tscadc_readl(tscadc, REG_CTRL);
173         ctrl |= CNTRLREG_TSCSSENB;
174         tscadc_writel(tscadc, REG_CTRL, ctrl);
175
176         /* TSC Cell */
177         cell = &tscadc->cells[TSC_CELL];
178         cell->name = "tsc";
179         cell->platform_data = tscadc;
180         cell->pdata_size = sizeof(*tscadc);
181
182         /* ADC Cell */
183         cell = &tscadc->cells[ADC_CELL];
184         cell->name = "tiadc";
185         cell->platform_data = tscadc;
186         cell->pdata_size = sizeof(*tscadc);
187
188         err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells,
189                         TSCADC_CELLS, NULL, 0, NULL);
190         if (err < 0)
191                 goto err_disable_clk;
192
193         device_init_wakeup(&pdev->dev, true);
194         platform_set_drvdata(pdev, tscadc);
195
196         return 0;
197
198 err_disable_clk:
199         pm_runtime_put_sync(&pdev->dev);
200         pm_runtime_disable(&pdev->dev);
201 ret:
202         return err;
203 }
204
205 static int __devexit ti_tscadc_remove(struct platform_device *pdev)
206 {
207         struct ti_tscadc_dev    *tscadc = platform_get_drvdata(pdev);
208
209         tscadc_writel(tscadc, REG_SE, 0x00);
210
211         pm_runtime_put_sync(&pdev->dev);
212         pm_runtime_disable(&pdev->dev);
213
214         mfd_remove_devices(tscadc->dev);
215
216         return 0;
217 }
218
219 #ifdef CONFIG_PM
220 static int tscadc_suspend(struct device *dev)
221 {
222         struct ti_tscadc_dev    *tscadc_dev = dev_get_drvdata(dev);
223
224         tscadc_writel(tscadc_dev, REG_SE, 0x00);
225         pm_runtime_put_sync(dev);
226
227         return 0;
228 }
229
230 static int tscadc_resume(struct device *dev)
231 {
232         struct ti_tscadc_dev    *tscadc_dev = dev_get_drvdata(dev);
233         unsigned int restore, ctrl;
234
235         pm_runtime_get_sync(dev);
236
237         /* context restore */
238         ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_TSCENB |
239                         CNTRLREG_STEPID | CNTRLREG_4WIRE;
240         tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
241         tscadc_idle_config(tscadc_dev);
242         tscadc_writel(tscadc_dev, REG_SE, STPENB_STEPENB);
243         restore = tscadc_readl(tscadc_dev, REG_CTRL);
244         tscadc_writel(tscadc_dev, REG_CTRL,
245                         (restore | CNTRLREG_TSCSSENB));
246
247         return 0;
248 }
249
250 static const struct dev_pm_ops tscadc_pm_ops = {
251         .suspend = tscadc_suspend,
252         .resume = tscadc_resume,
253 };
254 #define TSCADC_PM_OPS (&tscadc_pm_ops)
255 #else
256 #define TSCADC_PM_OPS NULL
257 #endif
258
259 static struct platform_driver ti_tscadc_driver = {
260         .driver = {
261                 .name   = "ti_tscadc",
262                 .owner  = THIS_MODULE,
263                 .pm     = TSCADC_PM_OPS,
264         },
265         .probe  = ti_tscadc_probe,
266         .remove = __devexit_p(ti_tscadc_remove),
267
268 };
269
270 module_platform_driver(ti_tscadc_driver);
271
272 MODULE_DESCRIPTION("TI touchscreen / ADC MFD controller driver");
273 MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
274 MODULE_LICENSE("GPL");