Re: [PATCH 1/2] cs5535-gpio: add AMD CS5535/CS5536 GPIO driver support

["Tobias Müller" <Tobias_Mueller@twam.info>]

Here's the promised patch. :) I tried to solve all issues I had with
Andres' patch.



From: Tobias Mueller <Tobias_Mueller@twam.info>

Added mask to enable/disable some GPIO pins.
Added names for GPIO pins.
Added code on GPIO initialisation to disable output/input aux functions.

Signed-off-by: Tobias Mueller <Tobias_Mueller@twam.info>
---
diff --git a/drivers/gpio/cs5535-gpio.c b/drivers/gpio/cs5535-gpio.c
index 5613889..8a0b290 100644
--- a/drivers/gpio/cs5535-gpio.c
+++ b/drivers/gpio/cs5535-gpio.c
@@ -18,6 +18,11 @@

 #define DRV_NAME "cs5535-gpio"
 #define GPIO_BAR 1
+#define GPIO_DEFAULT_MASK 0x0B003C66
+
+static ulong mask = GPIO_DEFAULT_MASK;
+module_param_named(mask, mask, ulong, 0444);
+MODULE_PARM_DESC(mask, "GPIO channel mask.");

 static struct cs5535_gpio_chip {
 	struct gpio_chip chip;
@@ -102,6 +107,38 @@ EXPORT_SYMBOL_GPL(cs5535_gpio_isset);
  * Generic gpio_chip API support.
  */

+static int chip_gpio_request(struct gpio_chip *c, unsigned offset)
+{
+	struct cs5535_gpio_chip *chip = (struct cs5535_gpio_chip *) c;
+	unsigned long flags;
+
+	spin_lock_irqsave(&chip->lock, flags);
+
+	/* check if this pin is available */
+	if ((mask & (1 << offset)) == 0) {
+		printk(KERN_INFO DRV_NAME
+		       ": pin %u is not available (check mask)\n", offset);
+		return -EINVAL;
+	}
+
+	/* disable output aux 1 & 2 on this pin */
+	__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_AUX1);
+	__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_AUX2);
+
+	/* disable input aux 1 on this pin */
+	__cs5535_gpio_clear(chip, offset, GPIO_INPUT_AUX1);
+
+	/* disable output */
+	__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_ENABLE);
+
+	/* enable input */
+	__cs5535_gpio_set(chip, offset, GPIO_INPUT_ENABLE);
+
+	spin_unlock_irqrestore(&chip->lock, flags);
+
+	return 0;
+}
+
 static int chip_gpio_get(struct gpio_chip *chip, unsigned offset)
 {
 	return cs5535_gpio_isset(offset, GPIO_OUTPUT_VAL);
@@ -145,19 +182,34 @@ static int chip_direction_output(struct
gpio_chip *c, unsigned offset, int val)
 	return 0;
 }

+static char *cs5535_gpio_names[] = {
+	"GPIO0", "GPIO1", "GPIO2", "GPIO3",
+	"GPIO4", "GPIO5", "GPIO6", "GPIO7",
+	"GPIO8", "GPIO9", "GPIO10", "GPIO11",
+	"GPIO12", "GPIO13", "GPIO14", "GPIO15",
+	"GPIO16", "GPIO17", "GPIO18", "GPIO19",
+	"GPIO20", "GPIO21", "GPIO22", NULL,
+	"GPIO24", "GPIO25", "GPIO26", "GPIO27",
+	"GPIO28", NULL, NULL, NULL,
+};
+
 static struct cs5535_gpio_chip cs5535_gpio_chip = {
 	.chip = {
 		.owner = THIS_MODULE,
 		.label = DRV_NAME,

 		.base = 0,
-		.ngpio = 28,
+		.ngpio = 32,
+		.names = cs5535_gpio_names,
+
+		.request = chip_gpio_request,

 		.get = chip_gpio_get,
 		.set = chip_gpio_set,

 		.direction_input = chip_direction_input,
 		.direction_output = chip_direction_output,
+
 	},
 };

@@ -165,6 +217,7 @@ static int __init cs5535_gpio_probe(struct pci_dev *pdev,
 		const struct pci_device_id *pci_id)
 {
 	int err;
+	ulong mask_orig = mask;

 	/* There are two ways to get the GPIO base address; one is by
 	 * fetching it from MSR_LBAR_GPIO, the other is by reading the
@@ -193,6 +246,18 @@ static int __init cs5535_gpio_probe(struct pci_dev *pdev,
 	dev_info(&pdev->dev, "allocated PCI BAR #%d: base 0x%llx\n", GPIO_BAR,
 			(unsigned long long) cs5535_gpio_chip.base);

+	/* mask out reserved pins */
+	mask &= 0x1F7FFFFF;
+
+	/* do not allow pin 28, Power Button, as there's special handling
+	 * in the PMC needed. (note 12, p. 48) */
+	mask &= ~(1 << 28);
+
+	if (mask_orig != mask)
+		printk(KERN_INFO DRV_NAME
+		       ": mask changed from 0x%08lX to 0x%08lX\n",
+		       mask_orig, mask);
+
 	/* finally, register with the generic GPIO API */
 	err = gpiochip_add(&cs5535_gpio_chip.chip);
 	if (err) {