[PATCH 2/5] iio: at91: Use different prescal, startup mask in MR for different IP

[Josh Wu]

For at91 boards, there are different IPs for adc. Different IPs has different
STARTUP & PRESCAL mask in ADC_MR.

This patch can change the masks according to the different IP version.

Signed-off-by: Josh Wu <josh.wu at atmel.com>
---
 arch/arm/mach-at91/include/mach/at91_adc.h |    9 ++++--
 drivers/iio/adc/at91_adc.c                 |   48 ++++++++++++++++++++++++++--
 2 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/arch/arm/mach-at91/include/mach/at91_adc.h b/arch/arm/mach-at91/include/mach/at91_adc.h
index 8e7ed5c..ab273ee 100644
--- a/arch/arm/mach-at91/include/mach/at91_adc.h
+++ b/arch/arm/mach-at91/include/mach/at91_adc.h
@@ -28,9 +28,12 @@
 #define			AT91_ADC_TRGSEL_EXTERNAL	(6 << 1)
 #define		AT91_ADC_LOWRES		(1 << 4)	/* Low Resolution */
 #define		AT91_ADC_SLEEP		(1 << 5)	/* Sleep Mode */
-#define		AT91_ADC_PRESCAL	(0x3f << 8)	/* Prescalar Rate Selection */
+#define		AT91_ADC_PRESCAL	(0xff << 8)	/* Prescalar Rate Selection */
+#define		AT91_ADC_PRESCAL_9260	(0x3f << 8)
 #define			AT91_ADC_PRESCAL_(x)	((x) << 8)
-#define		AT91_ADC_STARTUP	(0x1f << 16)	/* Startup Up Time */
+#define		AT91_ADC_STARTUP	(0xf << 16)	/* Startup Up Time */
+#define		AT91_ADC_STARTUP_9260	(0x1f << 16)
+#define		AT91_ADC_STARTUP_9G45	(0x7f << 16)
 #define			AT91_ADC_STARTUP_(x)	((x) << 16)
 #define		AT91_ADC_SHTIM		(0xf  << 24)	/* Sample & Hold Time */
 #define			AT91_ADC_SHTIM_(x)	((x) << 24)
@@ -58,4 +61,6 @@
 #define AT91_ADC_CHR(n)		(0x30 + ((n) * 4))	/* Channel Data Register N */
 #define		AT91_ADC_DATA		(0x3ff)
 
+#define AT91_ADC_VERSION	0xFC
+
 #endif
diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
index 18bd54f..14e99ba 100644
--- a/drivers/iio/adc/at91_adc.c
+++ b/drivers/iio/adc/at91_adc.c
@@ -39,6 +39,12 @@
 #define at91_adc_writel(st, reg, val) \
 	(writel_relaxed(val, st->reg_base + reg))
 
+struct at91_adc_caps {
+	bool	has_tsmr;	/* only at91sam9x5, sama5d3 have TSMR reg */
+	u32	mr_prescal_mask;
+	u32	mr_startup_mask;
+};
+
 struct at91_adc_state {
 	struct clk		*adc_clk;
 	u16			*buffer;
@@ -62,6 +68,7 @@ struct at91_adc_state {
 	u32			res;		/* resolution used for convertions */
 	bool			low_res;	/* the resolution corresponds to the lowest one */
 	wait_queue_head_t	wq_data_avail;
+	struct at91_adc_caps	caps;
 };
 
 static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
@@ -580,6 +587,41 @@ static const struct iio_info at91_adc_info = {
 	.read_raw = &at91_adc_read_raw,
 };
 
+/*
+ * Since atmel adc support different ip for touchscreen mode. Through the
+ * IP check, we will know the touchscreen capbilities.
+ */
+static void atmel_adc_get_cap(struct at91_adc_state *st)
+{
+	unsigned int version;
+	struct iio_dev *idev = iio_priv_to_dev(st);
+
+	version = at91_adc_readl(st, AT91_ADC_VERSION);
+	dev_dbg(&idev->dev, "version: 0x%x\n", version);
+
+	st->caps.mr_prescal_mask = AT91_ADC_PRESCAL_9260;
+	st->caps.mr_startup_mask = AT91_ADC_STARTUP_9260;
+
+	/* keep only major version number */
+	switch (version & 0xf00) {
+	case 0x500:	/* SAMA5D3 */
+	case 0x400:	/* AT91SAM9X5/9N12 */
+		st->caps.has_tsmr = 1;
+		st->caps.mr_startup_mask = AT91_ADC_STARTUP;
+	case 0x200:	/* AT91SAM9M10/9G45 */
+		st->caps.mr_prescal_mask = AT91_ADC_PRESCAL;
+
+		if ((version & 0xf00) == 0x200)
+			st->caps.mr_startup_mask = AT91_ADC_STARTUP_9G45;
+	case 0x100:	/* AT91SAM9260/9G20 */
+		break;
+	default:
+		dev_warn(&idev->dev,
+				"Unmanaged adc version, use minimal capabilities\n");
+		break;
+	};
+}
+
 static int at91_adc_probe(struct platform_device *pdev)
 {
 	unsigned int prsc, mstrclk, ticks, adc_clk, adc_clk_khz, shtim;
@@ -645,6 +687,8 @@ static int at91_adc_probe(struct platform_device *pdev)
 		goto error_free_device;
 	}
 
+	atmel_adc_get_cap(st);
+
 	st->clk = devm_clk_get(&pdev->dev, "adc_clk");
 	if (IS_ERR(st->clk)) {
 		dev_err(&pdev->dev, "Failed to get the clock.\n");
@@ -704,8 +748,8 @@ static int at91_adc_probe(struct platform_device *pdev)
 	shtim = round_up((st->sample_hold_time * adc_clk_khz /
 			  1000) - 1, 1);
 
-	reg = AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL;
-	reg |= AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP;
+	reg = AT91_ADC_PRESCAL_(prsc) & st->caps.mr_prescal_mask;
+	reg |= AT91_ADC_STARTUP_(ticks) & st->caps.mr_startup_mask;
 	if (st->low_res)
 		reg |= AT91_ADC_LOWRES;
 	if (st->sleep_mode)
-- 
1.7.10