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