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authorAndres Salomon <dilinger@collabora.co.uk>2009-12-14 18:00:32 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-12-15 08:53:27 -0800
commit5f0a96b044d8edaee20f4a32ef6c393599ca55f8 (patch)
treea46994e95854d1771ea6829826793f8bceb39751 /drivers/gpio/cs5535-gpio.c
parent1f2f38d89d1eced2079189cd880eeacee378370a (diff)
cs5535-gpio: add AMD CS5535/CS5536 GPIO driver support
This creates a CS5535/CS5536 GPIO driver which uses a gpio_chip backend (allowing GPIO users to use the generic GPIO API if desired) while also allowing architecture-specific users directly (via the cs5535_gpio_* functions). Tested on an OLPC machine. Some Leemotes also use CS5536 (with a mips cpu), which is why this is in drivers/gpio rather than arch/x86. Currently, it conflicts with older geode GPIO support; once MFGPT support is reworked to also be more generic, the older geode code will be removed. Signed-off-by: Andres Salomon <dilinger@collabora.co.uk> Cc: Takashi Iwai <tiwai@suse.de> Cc: Jordan Crouse <jordan@cosmicpenguin.net> Cc: David Brownell <david-b@pacbell.net> Reviewed-by: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/gpio/cs5535-gpio.c')
-rw-r--r--drivers/gpio/cs5535-gpio.c282
1 files changed, 282 insertions, 0 deletions
diff --git a/drivers/gpio/cs5535-gpio.c b/drivers/gpio/cs5535-gpio.c
new file mode 100644
index 000000000000..56138893819a
--- /dev/null
+++ b/drivers/gpio/cs5535-gpio.c
@@ -0,0 +1,282 @@
+/*
+ * AMD CS5535/CS5536 GPIO driver
+ * Copyright (C) 2006 Advanced Micro Devices, Inc.
+ * Copyright (C) 2007-2009 Andres Salomon <dilinger@collabora.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public License
+ * as published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/gpio.h>
+#include <linux/io.h>
+#include <linux/cs5535.h>
+
+#define DRV_NAME "cs5535-gpio"
+#define GPIO_BAR 1
+
+static struct cs5535_gpio_chip {
+ struct gpio_chip chip;
+ resource_size_t base;
+
+ struct pci_dev *pdev;
+ spinlock_t lock;
+} cs5535_gpio_chip;
+
+/*
+ * The CS5535/CS5536 GPIOs support a number of extra features not defined
+ * by the gpio_chip API, so these are exported. For a full list of the
+ * registers, see include/linux/cs5535.h.
+ */
+
+static void __cs5535_gpio_set(struct cs5535_gpio_chip *chip, unsigned offset,
+ unsigned int reg)
+{
+ if (offset < 16)
+ /* low bank register */
+ outl(1 << offset, chip->base + reg);
+ else
+ /* high bank register */
+ outl(1 << (offset - 16), chip->base + 0x80 + reg);
+}
+
+void cs5535_gpio_set(unsigned offset, unsigned int reg)
+{
+ struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
+ unsigned long flags;
+
+ spin_lock_irqsave(&chip->lock, flags);
+ __cs5535_gpio_set(chip, offset, reg);
+ spin_unlock_irqrestore(&chip->lock, flags);
+}
+EXPORT_SYMBOL_GPL(cs5535_gpio_set);
+
+static void __cs5535_gpio_clear(struct cs5535_gpio_chip *chip, unsigned offset,
+ unsigned int reg)
+{
+ if (offset < 16)
+ /* low bank register */
+ outl(1 << (offset + 16), chip->base + reg);
+ else
+ /* high bank register */
+ outl(1 << offset, chip->base + 0x80 + reg);
+}
+
+void cs5535_gpio_clear(unsigned offset, unsigned int reg)
+{
+ struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
+ unsigned long flags;
+
+ spin_lock_irqsave(&chip->lock, flags);
+ __cs5535_gpio_clear(chip, offset, reg);
+ spin_unlock_irqrestore(&chip->lock, flags);
+}
+EXPORT_SYMBOL_GPL(cs5535_gpio_clear);
+
+int cs5535_gpio_isset(unsigned offset, unsigned int reg)
+{
+ struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
+ unsigned long flags;
+ long val;
+
+ spin_lock_irqsave(&chip->lock, flags);
+ if (offset < 16)
+ /* low bank register */
+ val = inl(chip->base + reg);
+ else {
+ /* high bank register */
+ val = inl(chip->base + 0x80 + reg);
+ offset -= 16;
+ }
+ spin_unlock_irqrestore(&chip->lock, flags);
+
+ return (val & (1 << offset)) ? 1 : 0;
+}
+EXPORT_SYMBOL_GPL(cs5535_gpio_isset);
+
+/*
+ * Generic gpio_chip API support.
+ */
+
+static int chip_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ return cs5535_gpio_isset(offset, GPIO_OUTPUT_VAL);
+}
+
+static void chip_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
+{
+ if (val)
+ cs5535_gpio_set(offset, GPIO_OUTPUT_VAL);
+ else
+ cs5535_gpio_clear(offset, GPIO_OUTPUT_VAL);
+}
+
+static int chip_direction_input(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);
+ __cs5535_gpio_set(chip, offset, GPIO_INPUT_ENABLE);
+ spin_unlock_irqrestore(&chip->lock, flags);
+
+ return 0;
+}
+
+static int chip_direction_output(struct gpio_chip *c, unsigned offset, int val)
+{
+ struct cs5535_gpio_chip *chip = (struct cs5535_gpio_chip *) c;
+ unsigned long flags;
+
+ spin_lock_irqsave(&chip->lock, flags);
+
+ __cs5535_gpio_set(chip, offset, GPIO_OUTPUT_ENABLE);
+ if (val)
+ __cs5535_gpio_set(chip, offset, GPIO_OUTPUT_VAL);
+ else
+ __cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_VAL);
+
+ spin_unlock_irqrestore(&chip->lock, flags);
+
+ return 0;
+}
+
+static struct cs5535_gpio_chip cs5535_gpio_chip = {
+ .chip = {
+ .owner = THIS_MODULE,
+ .label = DRV_NAME,
+
+ .base = 0,
+ .ngpio = 28,
+
+ .get = chip_gpio_get,
+ .set = chip_gpio_set,
+
+ .direction_input = chip_direction_input,
+ .direction_output = chip_direction_output,
+ },
+};
+
+static int __init cs5535_gpio_probe(struct pci_dev *pdev,
+ const struct pci_device_id *pci_id)
+{
+ int err;
+
+ /* 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
+ * PCI BAR info. The latter method is easier (especially across
+ * different architectures), so we'll stick with that for now. If
+ * it turns out to be unreliable in the face of crappy BIOSes, we
+ * can always go back to using MSRs.. */
+
+ err = pci_enable_device_io(pdev);
+ if (err) {
+ dev_err(&pdev->dev, "can't enable device IO\n");
+ goto done;
+ }
+
+ err = pci_request_region(pdev, GPIO_BAR, DRV_NAME);
+ if (err) {
+ dev_err(&pdev->dev, "can't alloc PCI BAR #%d\n", GPIO_BAR);
+ goto done;
+ }
+
+ /* set up the driver-specific struct */
+ cs5535_gpio_chip.base = pci_resource_start(pdev, GPIO_BAR);
+ cs5535_gpio_chip.pdev = pdev;
+ spin_lock_init(&cs5535_gpio_chip.lock);
+
+ dev_info(&pdev->dev, "allocated PCI BAR #%d: base 0x%llx\n", GPIO_BAR,
+ (unsigned long long) cs5535_gpio_chip.base);
+
+ /* finally, register with the generic GPIO API */
+ err = gpiochip_add(&cs5535_gpio_chip.chip);
+ if (err) {
+ dev_err(&pdev->dev, "failed to register gpio chip\n");
+ goto release_region;
+ }
+
+ printk(KERN_INFO DRV_NAME ": GPIO support successfully loaded.\n");
+ return 0;
+
+release_region:
+ pci_release_region(pdev, GPIO_BAR);
+done:
+ return err;
+}
+
+static void __exit cs5535_gpio_remove(struct pci_dev *pdev)
+{
+ int err;
+
+ err = gpiochip_remove(&cs5535_gpio_chip.chip);
+ if (err) {
+ /* uhh? */
+ dev_err(&pdev->dev, "unable to remove gpio_chip?\n");
+ }
+ pci_release_region(pdev, GPIO_BAR);
+}
+
+static struct pci_device_id cs5535_gpio_pci_tbl[] = {
+ { PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_CS5535_ISA) },
+ { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA) },
+ { 0, },
+};
+MODULE_DEVICE_TABLE(pci, cs5535_gpio_pci_tbl);
+
+/*
+ * We can't use the standard PCI driver registration stuff here, since
+ * that allows only one driver to bind to each PCI device (and we want
+ * multiple drivers to be able to bind to the device). Instead, manually
+ * scan for the PCI device, request a single region, and keep track of the
+ * devices that we're using.
+ */
+
+static int __init cs5535_gpio_scan_pci(void)
+{
+ struct pci_dev *pdev;
+ int err = -ENODEV;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(cs5535_gpio_pci_tbl); i++) {
+ pdev = pci_get_device(cs5535_gpio_pci_tbl[i].vendor,
+ cs5535_gpio_pci_tbl[i].device, NULL);
+ if (pdev) {
+ err = cs5535_gpio_probe(pdev, &cs5535_gpio_pci_tbl[i]);
+ if (err)
+ pci_dev_put(pdev);
+
+ /* we only support a single CS5535/6 southbridge */
+ break;
+ }
+ }
+
+ return err;
+}
+
+static void __exit cs5535_gpio_free_pci(void)
+{
+ cs5535_gpio_remove(cs5535_gpio_chip.pdev);
+ pci_dev_put(cs5535_gpio_chip.pdev);
+}
+
+static int __init cs5535_gpio_init(void)
+{
+ return cs5535_gpio_scan_pci();
+}
+
+static void __exit cs5535_gpio_exit(void)
+{
+ cs5535_gpio_free_pci();
+}
+
+module_init(cs5535_gpio_init);
+module_exit(cs5535_gpio_exit);
+
+MODULE_AUTHOR("Andres Salomon <dilinger@collabora.co.uk>");
+MODULE_DESCRIPTION("AMD CS5535/CS5536 GPIO driver");
+MODULE_LICENSE("GPL");