iio: at91: Use different prescal, startup mask in MR for different IP

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

Signed-off-by: Josh Wu <josh.wu@atmel.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/arch/arm/mach-at91/include/mach/at91_adc.h b/arch/arm/mach-at91/include/mach/at91_adc.h
index bea1a20..048a57f 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_9260	(0x3f << 8)	/* Prescalar Rate Selection */
+#define		AT91_ADC_PRESCAL_9G45	(0xff << 8)
 #define			AT91_ADC_PRESCAL_(x)	((x) << 8)
-#define		AT91_ADC_STARTUP	(0x1f << 16)	/* Startup Up Time */
+#define		AT91_ADC_STARTUP_9260	(0x1f << 16)	/* Startup Up Time */
+#define		AT91_ADC_STARTUP_9G45	(0x7f << 16)
+#define		AT91_ADC_STARTUP_9X5	(0xf << 16)
 #define			AT91_ADC_STARTUP_(x)	((x) << 16)
 #define		AT91_ADC_SHTIM		(0xf  << 24)	/* Sample & Hold Time */
 #define			AT91_ADC_SHTIM_(x)	((x) << 24)
diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
index ed5eebc..84be63b 100644
--- a/drivers/iio/adc/at91_adc.c
+++ b/drivers/iio/adc/at91_adc.c
@@ -672,8 +672,8 @@
 	shtim = round_up((st->sample_hold_time * adc_clk /
 			  1000000) - 1, 1);
 
-	reg = AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL;
-	reg |= AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP;
+	reg = AT91_ADC_PRESCAL_(prsc) & st->registers->mr_prescal_mask;
+	reg |= AT91_ADC_STARTUP_(ticks) & st->registers->mr_startup_mask;
 	if (st->low_res)
 		reg |= AT91_ADC_LOWRES;
 	if (st->sleep_mode)
@@ -746,6 +746,8 @@
 		.drdy_mask = AT91_ADC_DRDY,
 		.status_register = AT91_ADC_SR,
 		.trigger_register = AT91_ADC_TRGR_9260,
+		.mr_prescal_mask = AT91_ADC_PRESCAL_9260,
+		.mr_startup_mask = AT91_ADC_STARTUP_9260,
 	},
 };
 
@@ -755,6 +757,8 @@
 		.drdy_mask = AT91_ADC_DRDY,
 		.status_register = AT91_ADC_SR,
 		.trigger_register = AT91_ADC_TRGR_9G45,
+		.mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
+		.mr_startup_mask = AT91_ADC_STARTUP_9G45,
 	},
 };
 
@@ -764,6 +768,9 @@
 		.drdy_mask = AT91_ADC_SR_DRDY_9X5,
 		.status_register = AT91_ADC_SR_9X5,
 		.trigger_register = AT91_ADC_TRGR_9X5,
+		/* prescal mask is same as 9G45 */
+		.mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
+		.mr_startup_mask = AT91_ADC_STARTUP_9X5,
 	},
 };
 
diff --git a/include/linux/platform_data/at91_adc.h b/include/linux/platform_data/at91_adc.h
index e15745b..b3ca1e9 100644
--- a/include/linux/platform_data/at91_adc.h
+++ b/include/linux/platform_data/at91_adc.h
@@ -14,12 +14,16 @@
 			(Interruptions registers mostly)
  * @status_register:	Offset of the Interrupt Status Register
  * @trigger_register:	Offset of the Trigger setup register
+ * @mr_prescal_mask:	Mask of the PRESCAL field in the adc MR register
+ * @mr_startup_mask:	Mask of the STARTUP field in the adc MR register
  */
 struct at91_adc_reg_desc {
 	u8	channel_base;
 	u32	drdy_mask;
 	u8	status_register;
 	u8	trigger_register;
+	u32	mr_prescal_mask;
+	u32	mr_startup_mask;
 };
 
 /**