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23#include <linux/module.h>
24#include <linux/platform_device.h>
25#include <linux/interrupt.h>
26#include <linux/device.h>
27#include <linux/kernel.h>
28#include <linux/slab.h>
29#include <linux/io.h>
30#include <linux/clk.h>
31#include <linux/err.h>
32#include <linux/completion.h>
33#include <linux/of.h>
34
35#include <linux/iio/iio.h>
36#include <linux/iio/sysfs.h>
37
38
39
40
41#define LPC32XX_ADC_SELECT(x) ((x) + 0x04)
42#define LPC32XX_ADC_CTRL(x) ((x) + 0x08)
43#define LPC32XX_ADC_VALUE(x) ((x) + 0x48)
44
45
46#define AD_REFm 0x00000200
47#define AD_REFp 0x00000080
48#define AD_IN 0x00000010
49
50#define AD_INTERNAL 0x00000004
51
52
53#define AD_STROBE 0x00000002
54#define AD_PDN_CTRL 0x00000004
55
56
57#define ADC_VALUE_MASK 0x000003FF
58
59#define MOD_NAME "lpc32xx-adc"
60
61struct lpc32xx_adc_info {
62 void __iomem *adc_base;
63 struct clk *clk;
64 struct completion completion;
65
66 u32 value;
67};
68
69static int lpc32xx_read_raw(struct iio_dev *indio_dev,
70 struct iio_chan_spec const *chan,
71 int *val,
72 int *val2,
73 long mask)
74{
75 struct lpc32xx_adc_info *info = iio_priv(indio_dev);
76
77 if (mask == IIO_CHAN_INFO_RAW) {
78 mutex_lock(&indio_dev->mlock);
79 clk_enable(info->clk);
80
81 __raw_writel(AD_INTERNAL | (chan->address) | AD_REFp | AD_REFm,
82 LPC32XX_ADC_SELECT(info->adc_base));
83
84 __raw_writel(AD_PDN_CTRL | AD_STROBE,
85 LPC32XX_ADC_CTRL(info->adc_base));
86 wait_for_completion(&info->completion);
87 clk_disable(info->clk);
88 *val = info->value;
89 mutex_unlock(&indio_dev->mlock);
90
91 return IIO_VAL_INT;
92 }
93
94 return -EINVAL;
95}
96
97static const struct iio_info lpc32xx_adc_iio_info = {
98 .read_raw = &lpc32xx_read_raw,
99 .driver_module = THIS_MODULE,
100};
101
102#define LPC32XX_ADC_CHANNEL(_index) { \
103 .type = IIO_VOLTAGE, \
104 .indexed = 1, \
105 .channel = _index, \
106 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
107 .address = AD_IN * _index, \
108 .scan_index = _index, \
109}
110
111static const struct iio_chan_spec lpc32xx_adc_iio_channels[] = {
112 LPC32XX_ADC_CHANNEL(0),
113 LPC32XX_ADC_CHANNEL(1),
114 LPC32XX_ADC_CHANNEL(2),
115};
116
117static irqreturn_t lpc32xx_adc_isr(int irq, void *dev_id)
118{
119 struct lpc32xx_adc_info *info = (struct lpc32xx_adc_info *) dev_id;
120
121
122 info->value = __raw_readl(LPC32XX_ADC_VALUE(info->adc_base)) &
123 ADC_VALUE_MASK;
124 complete(&info->completion);
125
126 return IRQ_HANDLED;
127}
128
129static int lpc32xx_adc_probe(struct platform_device *pdev)
130{
131 struct lpc32xx_adc_info *info = NULL;
132 struct resource *res;
133 int retval = -ENODEV;
134 struct iio_dev *iodev = NULL;
135 int irq;
136
137 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
138 if (!res) {
139 dev_err(&pdev->dev, "failed to get platform I/O memory\n");
140 retval = -EBUSY;
141 goto errout1;
142 }
143
144 iodev = iio_device_alloc(sizeof(struct lpc32xx_adc_info));
145 if (!iodev) {
146 dev_err(&pdev->dev, "failed allocating iio device\n");
147 retval = -ENOMEM;
148 goto errout1;
149 }
150
151 info = iio_priv(iodev);
152
153 info->adc_base = ioremap(res->start, resource_size(res));
154 if (!info->adc_base) {
155 dev_err(&pdev->dev, "failed mapping memory\n");
156 retval = -EBUSY;
157 goto errout2;
158 }
159
160 info->clk = clk_get(&pdev->dev, NULL);
161 if (IS_ERR(info->clk)) {
162 dev_err(&pdev->dev, "failed getting clock\n");
163 goto errout3;
164 }
165
166 irq = platform_get_irq(pdev, 0);
167 if ((irq < 0) || (irq >= NR_IRQS)) {
168 dev_err(&pdev->dev, "failed getting interrupt resource\n");
169 retval = -EINVAL;
170 goto errout4;
171 }
172
173 retval = request_irq(irq, lpc32xx_adc_isr, 0, MOD_NAME, info);
174 if (retval < 0) {
175 dev_err(&pdev->dev, "failed requesting interrupt\n");
176 goto errout4;
177 }
178
179 platform_set_drvdata(pdev, iodev);
180
181 init_completion(&info->completion);
182
183 iodev->name = MOD_NAME;
184 iodev->dev.parent = &pdev->dev;
185 iodev->info = &lpc32xx_adc_iio_info;
186 iodev->modes = INDIO_DIRECT_MODE;
187 iodev->channels = lpc32xx_adc_iio_channels;
188 iodev->num_channels = ARRAY_SIZE(lpc32xx_adc_iio_channels);
189
190 retval = iio_device_register(iodev);
191 if (retval)
192 goto errout5;
193
194 dev_info(&pdev->dev, "LPC32XX ADC driver loaded, IRQ %d\n", irq);
195
196 return 0;
197
198errout5:
199 free_irq(irq, info);
200errout4:
201 clk_put(info->clk);
202errout3:
203 iounmap(info->adc_base);
204errout2:
205 iio_device_free(iodev);
206errout1:
207 return retval;
208}
209
210static int lpc32xx_adc_remove(struct platform_device *pdev)
211{
212 struct iio_dev *iodev = platform_get_drvdata(pdev);
213 struct lpc32xx_adc_info *info = iio_priv(iodev);
214 int irq = platform_get_irq(pdev, 0);
215
216 iio_device_unregister(iodev);
217 free_irq(irq, info);
218 platform_set_drvdata(pdev, NULL);
219 clk_put(info->clk);
220 iounmap(info->adc_base);
221 iio_device_free(iodev);
222
223 return 0;
224}
225
226#ifdef CONFIG_OF
227static const struct of_device_id lpc32xx_adc_match[] = {
228 { .compatible = "nxp,lpc3220-adc" },
229 {},
230};
231MODULE_DEVICE_TABLE(of, lpc32xx_adc_match);
232#endif
233
234static struct platform_driver lpc32xx_adc_driver = {
235 .probe = lpc32xx_adc_probe,
236 .remove = lpc32xx_adc_remove,
237 .driver = {
238 .name = MOD_NAME,
239 .owner = THIS_MODULE,
240 .of_match_table = of_match_ptr(lpc32xx_adc_match),
241 },
242};
243
244module_platform_driver(lpc32xx_adc_driver);
245
246MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
247MODULE_DESCRIPTION("LPC32XX ADC driver");
248MODULE_LICENSE("GPL");
249
