On 16/07/2013 10:35, Josh Wu :
Hi, Maxime
On 7/15/2013 8:58 PM, Maxime Ripard wrote:
Hi Josh,
On Sun, Jul 14, 2013 at 04:04:26PM +0800, Josh Wu wrote:
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@xxxxxxxxx>
---
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;
+ };
+}
Why don't you use different compatible names and derive your
capabilities from which compatible is declared.
It seems safer.
I see it as handier in the sense that a different IP version can be
compatible with an older IP version: so we do not need to modify the
driver just to use another SoC.
On your side Maxime, what makes you say that it is "safer"?
Ok, that make sense. I will use compatible names for the capabilities in
next version. Thanks.
Hold on a little bit Josh, I know that Jean-Christophe is not in favor
of the use of multiple compatible strings. So, as the code is already
there, let's wait and see if we find another argument...
Bye,
--
Nicolas Ferre
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