Thread (4 messages) flat view 4 messages, 2 authors, 2011-02-04

[PATCH 15/19] mc13xxx: mfd_cell is now implicitly available to drivers

From: Uwe Kleine-König <hidden>
Date: 2011-02-04 09:35:13
Also in: lkml

Hello Andres,

On Wed, Feb 02, 2011 at 08:20:15PM -0800, Andres Salomon wrote:
No need to explicitly set the cell's platform_data/data_size.

In this case, move the various platform_data pointers
to driver_data.  All of the clients which make use of it
are also changed.

Mfd-core makes a copy of platform_data, but driver_data keeps a pointer
to the original data.  Because each cell's platform_data previously
pointed to a local (stack) variable, the various ARM mach types that set
the pdata are updated to keep the memory around.
I didn't get this even after reading it 5 times.  You wrote in the
subject that drivers now have access to mfd_cell.  I don't see where
e.g. drivers/leds/leds-mc13783.c uses that?!  Does this depend on some
mfd-changes I don't see and this is just a first step?

After reading the changes I think I understood:

 - You made things that were passed as platform_data before available
   via driver_data.
 - Because platform_data is copied and driver_data is not at register
   time, the data being platform_data cannot be __initdata or stack
   local anymore, so this needs fixing.

In sum this results in .data becoming bigger (which is bad).

And I think this patch has a conceptual problem, too.  In my opionion
platform_data is the point to hand over platform specific data to a
driver.  driver_data is something that is private to the driver and has
to be considered opaque for the platform.  The driver was sort of OK
before ...
quoted hunk ↗ jump to hunk
diff --git a/arch/arm/mach-imx/mach-mx27_3ds.c b/arch/arm/mach-imx/mach-mx27_3ds.c
index 1643315..edcecaa 100644
--- a/arch/arm/mach-imx/mach-mx27_3ds.c
+++ b/arch/arm/mach-imx/mach-mx27_3ds.c
@@ -226,10 +226,14 @@ static struct mc13783_regulator_init_data mx27_3ds_regulators[] = {
 	},
 };
 
-/* MC13783 */
-static struct mc13783_platform_data mc13783_pdata __initdata = {
+static struct mc13783_regulator_platform_data mx27_regs = {
The prefix mx27 is misleading. If you want to take the machine name
into account use mx27_3ds, otherwise just use mc13783_regulator_pdata or
similar. (And note that "regs" isn't that good IMHO, too, as it might
stand for registers, too. And even mx27_3ds_regulators would be too
general. This applies to the changes below, too.)
 	.regulators = mx27_3ds_regulators,
 	.num_regulators = ARRAY_SIZE(mx27_3ds_regulators),
+};
+
+/* MC13783 */
a very minor nitpick is you moved the comment for mx27_3ds, but not for
e.g. mx31_3ds.
quoted hunk ↗ jump to hunk
+static struct mc13783_platform_data mc13783_pdata __initdata = {
+	.regulators = &mx27_regs,
 	.flags  = MC13783_USE_REGULATOR,
 };
 
diff --git a/arch/arm/mach-imx/mach-pcm038.c b/arch/arm/mach-imx/mach-pcm038.c
index 5056148..b5ae8cc 100644
--- a/arch/arm/mach-imx/mach-pcm038.c
+++ b/arch/arm/mach-imx/mach-pcm038.c
@@ -262,9 +262,13 @@ static struct mc13783_regulator_init_data pcm038_regulators[] = {
 	},
 };
 
-static struct mc13783_platform_data pcm038_pmic = {
+static struct mc13783_regulator_platform_data pcm038_regs = {
 	.regulators = pcm038_regulators,
 	.num_regulators = ARRAY_SIZE(pcm038_regulators),
+};
+
+static struct mc13783_platform_data pcm038_pmic = {
+	.regulators = &pcm038_regs,
 	.flags = MC13783_USE_ADC | MC13783_USE_REGULATOR |
 		 MC13783_USE_TOUCHSCREEN,
 };
diff --git a/arch/arm/mach-mx3/mach-mx31_3ds.c b/arch/arm/mach-mx3/mach-mx31_3ds.c
index 0d65db8..3e613ee 100644
--- a/arch/arm/mach-mx3/mach-mx31_3ds.c
+++ b/arch/arm/mach-mx3/mach-mx31_3ds.c
@@ -156,9 +156,13 @@ static struct mc13783_regulator_init_data mx31_3ds_regulators[] = {
 };
 
 /* MC13783 */
-static struct mc13783_platform_data mc13783_pdata __initdata = {
+static struct mc13783_regulator_platform_data mc13783_regs = {
 	.regulators = mx31_3ds_regulators,
 	.num_regulators = ARRAY_SIZE(mx31_3ds_regulators),
+};
+
+static struct mc13783_platform_data mc13783_pdata __initdata = {
+	.regulators = &mc13783_regs,
 	.flags  = MC13783_USE_REGULATOR | MC13783_USE_TOUCHSCREEN,
 };
 
diff --git a/arch/arm/mach-mx3/mach-mx31moboard.c b/arch/arm/mach-mx3/mach-mx31moboard.c
index 1aa8d65..424fbd9 100644
--- a/arch/arm/mach-mx3/mach-mx31moboard.c
+++ b/arch/arm/mach-mx3/mach-mx31moboard.c
@@ -267,9 +267,13 @@ static struct mc13783_leds_platform_data moboard_leds = {
 	.tc2_period = MC13783_LED_PERIOD_10MS,
 };
 
-static struct mc13783_platform_data moboard_pmic = {
+static struct mc13783_regulator_platform_data moboard_regs = {
 	.regulators = moboard_regulators,
 	.num_regulators = ARRAY_SIZE(moboard_regulators),
+};
+
+static struct mc13783_platform_data moboard_pmic = {
+	.regulators = &moboard_regs,
 	.leds = &moboard_leds,
 	.flags = MC13783_USE_REGULATOR | MC13783_USE_RTC |
 		MC13783_USE_ADC | MC13783_USE_LED,
diff --git a/drivers/leds/leds-mc13783.c b/drivers/leds/leds-mc13783.c
index f05bb08..687fb13 100644
--- a/drivers/leds/leds-mc13783.c
+++ b/drivers/leds/leds-mc13783.c
@@ -30,6 +30,7 @@ struct mc13783_led {
 	struct mc13783		*master;
 	enum led_brightness	new_brightness;
 	int			id;
+	int			num_leds;
 };
 
 #define MC13783_REG_LED_CONTROL_0	51
@@ -181,9 +182,9 @@ static int __devinit mc13783_led_setup(struct mc13783_led *led, int max_current)
 	return ret;
 }
 
-static int __devinit mc13783_leds_prepare(struct platform_device *pdev)
+static int __devinit mc13783_leds_prepare(struct platform_device *pdev,
+		struct mc13783_leds_platform_data *pdata)
 {
-	struct mc13783_leds_platform_data *pdata = dev_get_platdata(&pdev->dev);
 	struct mc13783 *dev = dev_get_drvdata(pdev->dev.parent);
 	int ret = 0;
 	int reg = 0;
@@ -264,7 +265,7 @@ out:
 
 static int __devinit mc13783_led_probe(struct platform_device *pdev)
 {
-	struct mc13783_leds_platform_data *pdata = dev_get_platdata(&pdev->dev);
+	struct mc13783_leds_platform_data *pdata = platform_get_drvdata(pdev);
 	struct mc13783_led_platform_data *led_cur;
 	struct mc13783_led *led, *led_dat;
 	int ret, i;
@@ -286,12 +287,15 @@ static int __devinit mc13783_led_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
-	ret = mc13783_leds_prepare(pdev);
+	ret = mc13783_leds_prepare(pdev, pdata);
 	if (ret) {
 		dev_err(&pdev->dev, "unable to init led driver\n");
 		goto err_free;
 	}
 
+	/* no need to save the num of LEDs for any other elements of 'led' */
+	led[0].num_leds = pdata->num_leds;
+
So for n leds you introduced n-1 useless ints.

So all in all, I don't like that change, maybe just because I don't
understand your motivation.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-K?nig            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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