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#define AT91SAM9X5_BASE_ADC 0xf804c000
#define AT91SAM9260_BASE_ADC 0xfffe0000
#define ADC_SHTIME_DEFAULT 0x05
#define ADC_STARTUP_DEFAULT 0x04
#define ADC_PRESCALE_DEFAULT 0x3F
#define ADC_MODE_DEFAULT \
((ADC_SHTIME_DEFAULT & 0x0F) << 24) | \
((ADC_STARTUP_DEFAULT & 0x1F) << 16) | \
((ADC_PRESCALE_DEFAULT & 0x3F) << 8)
#define ADC_CR_OFFSET 0x00
#define ADC_MR_OFFSET 0x04
#define ADC_CHER_OFFSET 0x10
#define ADC_CHDR_OFFSET 0x14
#define ADC_CHSR_OFFSET 0x18
#define ADC_SR_OFFSET 0x1C
#define ADC_LDCR_OFFSET 0x20
#define ADC_IER_OFFSET 0x14
#define ADC_IDR_OFFSET 0x28
#define ADC_IMR_OFFSET 0x2C
#define ADC_CDR0_OFFSET 0x30
#define ADC_CDR1_OFFSET 0x34
#define ADC_CDR2_OFFSET 0x38
#define ADC_CDR3_OFFSET 0x3C
void __iomem *adc_base;
struct clk *adc_clk;
#define ADC_CONVERT_RESET(base) writel(0x01, (base) + ADC_CR_OFFSET)
#define ADC_CONVERT_START(base) writel(0x02, (base) + ADC_CR_OFFSET)
static ssize_t mts_attr_show_adc(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int offset;
u32 value;
u32 chan_mask;
if (!DEVICE_CAPA(id_eeprom.capa, CAPA_ADC)) {
log_debug("ADC not available");
return -ENODEV;
}
if (!strcmp(attr->attr.name, "adc0")) {
offset = ADC_CDR0_OFFSET;
chan_mask = 0x01;
} else if (!strcmp(attr->attr.name, "adc1")) {
offset = ADC_CDR1_OFFSET;
chan_mask = 0x02;
} else if (!strcmp(attr->attr.name, "adc2")) {
offset = ADC_CDR2_OFFSET;
chan_mask = 0x04;
} else if (!strcmp(attr->attr.name, "adc3")) {
offset = ADC_CDR3_OFFSET;
chan_mask = 0x08;
} else {
log_notice("adc attr does not exist");
return -ENOENT;
}
mutex_lock(&mts_io_mutex);
// disable all channels and enable the one we want
writel(0x0F, adc_base + ADC_CHDR_OFFSET);
writel(chan_mask, adc_base + ADC_CHER_OFFSET);
ADC_CONVERT_START(adc_base);
// wait for conversion to complete (EOC bit set)
value = 0;
while (value != chan_mask) {
value = readl(adc_base + ADC_SR_OFFSET) & chan_mask;
log_debug("ADC_SR EOC [%X]", value);
}
// read result
value = readl(adc_base + offset);
mutex_unlock(&mts_io_mutex);
return sprintf(buf, "%lu\n", (unsigned long) value);
}
static DEVICE_ATTR_RO_MTS(dev_attr_adc0, "adc0", mts_attr_show_adc);
static DEVICE_ATTR_RO_MTS(dev_attr_adc1, "adc1", mts_attr_show_adc);
static DEVICE_ATTR_RO_MTS(dev_attr_adc2, "adc2", mts_attr_show_adc);
static DEVICE_ATTR_RO_MTS(dev_attr_adc3, "adc3", mts_attr_show_adc);
static int mts_io_board_adc_probe(struct platform_device *pdev)
{
int err;
adc_clk = clk_get(&pdev->dev, "adc_clk");
if (adc_clk) {
err = clk_prepare_enable(adc_clk);
if (err) {
log_error("clock failed to prepare+enable: %d\n", err);
return err;
}
#ifdef CONFIG_SOC_AT91SAM9X5
adc_base = ioremap(AT91SAM9X5_BASE_ADC, SZ_16K);
#else
adc_base = ioremap(AT91SAM9260_BASE_ADC, SZ_16K);
#endif
if (!adc_base) {
log_error("ioremap failed.\n");
return -ENOMEM;
}
ADC_CONVERT_RESET(adc_base);
writel(ADC_MODE_DEFAULT, adc_base + ADC_MR_OFFSET);
writel(0x000F0F0F, adc_base + ADC_IDR_OFFSET);
writel(0x0F, adc_base + ADC_CHDR_OFFSET);
}
return 0;
}
static int mts_io_board_adc_remove(struct platform_device *pdev)
{
if (adc_clk) {
int ret;
clk_disable_unprepare(adc_clk);
}
return 0;
}
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