On Wed, Jan 30, 2013 at 16:10:09, Koen Kooi wrote:

Op 24 jan. 2013, om 04:45 heeft "Patil, Rachna" [off-list ref] het volgende geschreven:

quoted

From: "Patil, Rachna" <redacted>

Make changes to add DT support in the MFD core driver.

Signed-off-by: Patil, Rachna <redacted>
---
Changes in v4:
	Non-standard properties prefixed with vendor name.

drivers/mfd/ti_am335x_tscadc.c |   28 +++++++++++++++++++++++-----
1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/drivers/mfd/ti_am335x_tscadc.c 

b/drivers/mfd/ti_am335x_tscadc.c index e9f3fb5..87b446b 100644

--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c

@@ -22,6 +22,8 @@

#include <linux/regmap.h>
#include <linux/mfd/core.h>
#include <linux/pm_runtime.h>
+#include <linux/of.h>
+#include <linux/of_device.h>

#include <linux/mfd/ti_am335x_tscadc.h> #include 
<linux/input/ti_am335x_tsc.h>

@@ -64,20 +66,31 @@ static	int ti_tscadc_probe(struct platform_device *pdev)

	struct resource		*res;
	struct clk		*clk;
	struct mfd_tscadc_board	*pdata = pdev->dev.platform_data;
+	struct device_node	*node = pdev->dev.of_node;
	struct mfd_cell		*cell;
	int			err, ctrl;
	int			clk_value, clock_rate;
-	int			tsc_wires, adc_channels = 0, total_channels;
+	int			tsc_wires = 0, adc_channels = 0, total_channels;

-	if (!pdata) {
+	if (!pdata && !pdev->dev.of_node) {
		dev_err(&pdev->dev, "Could not find platform data\n");
		return -EINVAL;
	}

-	if (pdata->adc_init)
-		adc_channels = pdata->adc_init->adc_channels;
+	if (pdev->dev.platform_data) {
+		if (pdata->tsc_init)
+			tsc_wires = pdata->tsc_init->wires;
+
+		if (pdata->adc_init)
+			adc_channels = pdata->adc_init->adc_channels;
+	} else {
+		node = of_find_node_by_name(pdev->dev.of_node, "tsc");
+		of_property_read_u32(node, "ti,wires", &tsc_wires);
+
+		node = of_find_node_by_name(pdev->dev.of_node, "adc");
+		of_property_read_u32(node, "ti,adc-channels", &adc_channels);
+	}

Since AM335x is DT only, why is there a platform data codepath and why is it the first branch it tries? And I guess the next question is related to the first: why doesn't it work when used with DT? When I copy over the nodes from the evm.dts to my board I get "tsc tsc: Missing platform data" in dmesg.

This IP came up 1st on AM335x, but it is not platform dependent. The driver can be used on other platforms where-in DT is not supported.
According to the maintainers platform data takes precedence over DT. Hence the order.

I do not see "Missing platform data" error msg in the latest driver. I am not able to trace from where this got populated.

What are the chances this driver will work when applied on top of 3.8-rcX? Has it even been tested with that? Has it been tested at all?

This driver has been tested on top of v3.8-rc3 on a AM335x EVM.

Regards,
Rachna