From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sundar R IYER <sundar.iyer@stericsson.com>
Subject: RE: [PATCH v3 1/1] input: add support for Nomadik SKE keypad
 controller
Date: Mon, 6 Sep 2010 17:16:01 +0200
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To: "Datta, Shubhrajyoti" <shubhrajyoti@ti.com>
Cc: "linux-input@vger.kernel.org" <linux-input@vger.kernel.org>, STEricsson_nomadik_linux <STEricsson_nomadik_linux@list.st.com>

Hi,

>-----Original Message-----
>From: Datta, Shubhrajyoti [mailto:shubhrajyoti@ti.com]
>> +     /* go through board initialiazation helpers */
>> +     if (keypad->board->init) {
>Did not understand this

>-----Original Message-----
>From: Dmitry Torokhov [mailto:dmitry.torokhov@gmail.com]
>> > > +
>> > > +     if (!keypad->board->init) {
>> > > +             dev_err(&pdev->dev, "NULL board initialization helper\n");
>> >
>> > Could be checked earlier. Also, does it have to be an error?
>> >
>>
>> The platform code takes care to request the GPIOs and the GPIO configurations.
>> Hence I return error in case the board configurations dont get completed.
>>
>
>PLanform author migth opt to do the initialization earlier, together
>with teh rest of GPIO configuration so it is all ready by the time the
>driver is loaded. I think we should give such an option.

I interpreted Dmitry's above suggestion as allowing the driver to proceed in case platform
Initialization is not done.

The [PATCH 2/2] ux500: add platform data for Nomadik SKE keypad controller adds this platform
data which is configuration of the GPIO pins like this.

+/*
+ * ske_set_gpio_row: request and set gpio rows  */ static int 
+ske_set_gpio_row(int gpio) {
+	int ret;
+
+	ret = gpio_request(gpio, "ske-kp");
+	if (ret < 0) {
+		pr_err("ske_set_gpio_row: gpio request failed\n");
+		return ret;
+	}
+
+	ret = gpio_direction_output(gpio, 1);
+	if (ret < 0) {
+		pr_err("ske_set_gpio_row: gpio direction failed\n");
+		gpio_free(gpio);
+	}
+
+	return ret;
+}
+
+/*
+ * ske_kp_init - enable the gpio configuration  */ static int 
+ske_kp_init(void) {
+	int ret, i;
+
+	for (i = 0; i < SKE_KPD_MAX_ROWS; i++) {
+		ret = ske_set_gpio_row(ske_kp_rows[i]);
+		if (ret < 0) {
+			pr_err("ske_kp_init: failed init\n");
+			return ret;
+		}
+	}
+
+	return 0;
+}

And hence I need to call this board init to make sure that I get the GPIO lines
for my device.

>> +
>> +     if (keypad->board->exit())
>> +             keypad->board->exit();
>What does this exit function do?
>Are you sure the exit function does not need the keypad clock?
>

Although I haven't added a exit function to the platform data, but from the platform
code posted from above, it is clear that there are no controller dependencies for the
board exit function.

Regards,
Sundar