blob: c4ec7779b394effbc1fbf7f90b819eddf54f7854 [file] [log] [blame]
Sanchayan Maity1b983bf2016-02-22 11:48:37 +05301/*
2 * Freescale Vybrid vf610 DAC driver
3 *
4 * Copyright 2016 Toradex AG
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 as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 */
16
17#include <linux/clk.h>
18#include <linux/err.h>
19#include <linux/interrupt.h>
20#include <linux/io.h>
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/platform_device.h>
24#include <linux/regulator/consumer.h>
25#include <linux/slab.h>
26
27#include <linux/iio/iio.h>
28#include <linux/iio/sysfs.h>
29
30#define VF610_DACx_STATCTRL 0x20
31
32#define VF610_DAC_DACEN BIT(15)
33#define VF610_DAC_DACRFS BIT(14)
34#define VF610_DAC_LPEN BIT(11)
35
36#define VF610_DAC_DAT0(x) ((x) & 0xFFF)
37
38enum vf610_conversion_mode_sel {
39 VF610_DAC_CONV_HIGH_POWER,
40 VF610_DAC_CONV_LOW_POWER,
41};
42
43struct vf610_dac {
44 struct clk *clk;
45 struct device *dev;
46 enum vf610_conversion_mode_sel conv_mode;
47 void __iomem *regs;
48};
49
50static void vf610_dac_init(struct vf610_dac *info)
51{
52 int val;
53
54 info->conv_mode = VF610_DAC_CONV_LOW_POWER;
55 val = VF610_DAC_DACEN | VF610_DAC_DACRFS |
56 VF610_DAC_LPEN;
57 writel(val, info->regs + VF610_DACx_STATCTRL);
58}
59
60static void vf610_dac_exit(struct vf610_dac *info)
61{
62 int val;
63
64 val = readl(info->regs + VF610_DACx_STATCTRL);
65 val &= ~VF610_DAC_DACEN;
66 writel(val, info->regs + VF610_DACx_STATCTRL);
67}
68
69static int vf610_set_conversion_mode(struct iio_dev *indio_dev,
70 const struct iio_chan_spec *chan,
71 unsigned int mode)
72{
73 struct vf610_dac *info = iio_priv(indio_dev);
74 int val;
75
76 mutex_lock(&indio_dev->mlock);
77 info->conv_mode = mode;
78 val = readl(info->regs + VF610_DACx_STATCTRL);
79 if (mode)
80 val |= VF610_DAC_LPEN;
81 else
82 val &= ~VF610_DAC_LPEN;
83 writel(val, info->regs + VF610_DACx_STATCTRL);
84 mutex_unlock(&indio_dev->mlock);
85
86 return 0;
87}
88
89static int vf610_get_conversion_mode(struct iio_dev *indio_dev,
90 const struct iio_chan_spec *chan)
91{
92 struct vf610_dac *info = iio_priv(indio_dev);
93
94 return info->conv_mode;
95}
96
97static const char * const vf610_conv_modes[] = { "high-power", "low-power" };
98
99static const struct iio_enum vf610_conversion_mode = {
100 .items = vf610_conv_modes,
101 .num_items = ARRAY_SIZE(vf610_conv_modes),
102 .get = vf610_get_conversion_mode,
103 .set = vf610_set_conversion_mode,
104};
105
106static const struct iio_chan_spec_ext_info vf610_ext_info[] = {
107 IIO_ENUM("conversion_mode", IIO_SHARED_BY_DIR,
108 &vf610_conversion_mode),
109 {},
110};
111
112#define VF610_DAC_CHAN(_chan_type) { \
113 .type = (_chan_type), \
114 .output = 1, \
115 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
116 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
117 .ext_info = vf610_ext_info, \
118}
119
120static const struct iio_chan_spec vf610_dac_iio_channels[] = {
121 VF610_DAC_CHAN(IIO_VOLTAGE),
122};
123
124static int vf610_read_raw(struct iio_dev *indio_dev,
125 struct iio_chan_spec const *chan,
126 int *val, int *val2,
127 long mask)
128{
129 struct vf610_dac *info = iio_priv(indio_dev);
130
131 switch (mask) {
132 case IIO_CHAN_INFO_RAW:
133 *val = VF610_DAC_DAT0(readl(info->regs));
134 return IIO_VAL_INT;
135 case IIO_CHAN_INFO_SCALE:
136 /*
137 * DACRFS is always 1 for valid reference and typical
138 * reference voltage as per Vybrid datasheet is 3.3V
139 * from section 9.1.2.1 of Vybrid datasheet
140 */
141 *val = 3300 /* mV */;
142 *val2 = 12;
143 return IIO_VAL_FRACTIONAL_LOG2;
144
145 default:
146 return -EINVAL;
147 }
148}
149
150static int vf610_write_raw(struct iio_dev *indio_dev,
151 struct iio_chan_spec const *chan,
152 int val, int val2,
153 long mask)
154{
155 struct vf610_dac *info = iio_priv(indio_dev);
156
157 switch (mask) {
158 case IIO_CHAN_INFO_RAW:
159 mutex_lock(&indio_dev->mlock);
160 writel(VF610_DAC_DAT0(val), info->regs);
161 mutex_unlock(&indio_dev->mlock);
162 return 0;
163
164 default:
165 return -EINVAL;
166 }
167}
168
169static const struct iio_info vf610_dac_iio_info = {
170 .driver_module = THIS_MODULE,
171 .read_raw = &vf610_read_raw,
172 .write_raw = &vf610_write_raw,
173};
174
175static const struct of_device_id vf610_dac_match[] = {
176 { .compatible = "fsl,vf610-dac", },
177 { /* sentinel */ }
178};
179MODULE_DEVICE_TABLE(of, vf610_dac_match);
180
181static int vf610_dac_probe(struct platform_device *pdev)
182{
183 struct iio_dev *indio_dev;
184 struct vf610_dac *info;
185 struct resource *mem;
186 int ret;
187
188 indio_dev = devm_iio_device_alloc(&pdev->dev,
189 sizeof(struct vf610_dac));
190 if (!indio_dev) {
191 dev_err(&pdev->dev, "Failed allocating iio device\n");
192 return -ENOMEM;
193 }
194
195 info = iio_priv(indio_dev);
196 info->dev = &pdev->dev;
197
198 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
199 info->regs = devm_ioremap_resource(&pdev->dev, mem);
200 if (IS_ERR(info->regs))
201 return PTR_ERR(info->regs);
202
203 info->clk = devm_clk_get(&pdev->dev, "dac");
204 if (IS_ERR(info->clk)) {
205 dev_err(&pdev->dev, "Failed getting clock, err = %ld\n",
206 PTR_ERR(info->clk));
207 return PTR_ERR(info->clk);
208 }
209
210 platform_set_drvdata(pdev, indio_dev);
211
212 indio_dev->name = dev_name(&pdev->dev);
213 indio_dev->dev.parent = &pdev->dev;
214 indio_dev->dev.of_node = pdev->dev.of_node;
215 indio_dev->info = &vf610_dac_iio_info;
216 indio_dev->modes = INDIO_DIRECT_MODE;
217 indio_dev->channels = vf610_dac_iio_channels;
218 indio_dev->num_channels = ARRAY_SIZE(vf610_dac_iio_channels);
219
220 ret = clk_prepare_enable(info->clk);
221 if (ret) {
222 dev_err(&pdev->dev,
223 "Could not prepare or enable the clock\n");
224 return ret;
225 }
226
227 vf610_dac_init(info);
228
229 ret = iio_device_register(indio_dev);
230 if (ret) {
231 dev_err(&pdev->dev, "Couldn't register the device\n");
232 goto error_iio_device_register;
233 }
234
235 return 0;
236
237error_iio_device_register:
238 clk_disable_unprepare(info->clk);
239
240 return ret;
241}
242
243static int vf610_dac_remove(struct platform_device *pdev)
244{
245 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
246 struct vf610_dac *info = iio_priv(indio_dev);
247
248 iio_device_unregister(indio_dev);
249 vf610_dac_exit(info);
250 clk_disable_unprepare(info->clk);
251
252 return 0;
253}
254
255#ifdef CONFIG_PM_SLEEP
256static int vf610_dac_suspend(struct device *dev)
257{
258 struct iio_dev *indio_dev = dev_get_drvdata(dev);
259 struct vf610_dac *info = iio_priv(indio_dev);
260
261 vf610_dac_exit(info);
262 clk_disable_unprepare(info->clk);
263
264 return 0;
265}
266
267static int vf610_dac_resume(struct device *dev)
268{
269 struct iio_dev *indio_dev = dev_get_drvdata(dev);
270 struct vf610_dac *info = iio_priv(indio_dev);
271 int ret;
272
273 ret = clk_prepare_enable(info->clk);
274 if (ret)
275 return ret;
276
277 vf610_dac_init(info);
278
279 return 0;
280}
281#endif
282
283static SIMPLE_DEV_PM_OPS(vf610_dac_pm_ops, vf610_dac_suspend, vf610_dac_resume);
284
285static struct platform_driver vf610_dac_driver = {
286 .probe = vf610_dac_probe,
287 .remove = vf610_dac_remove,
288 .driver = {
289 .name = "vf610-dac",
290 .of_match_table = vf610_dac_match,
291 .pm = &vf610_dac_pm_ops,
292 },
293};
294module_platform_driver(vf610_dac_driver);
295
296MODULE_AUTHOR("Sanchayan Maity <sanchayan.maity@toradex.com>");
297MODULE_DESCRIPTION("Freescale VF610 DAC driver");
298MODULE_LICENSE("GPL v2");