Date:	Wed, 16 Sep 2009 09:32:12 -0700
From:	Dave Hansen <dave@...1.net>
To:	dave@...1.net
Cc:	Richard Purdie <rpurdie@...ys.net>, linux-kernel@...r.kernel.org,
	Rodney Girod <rgirod@...focus.com>
Subject: [PATCH] LED driver for Intel NAS SS4200 series

Changes from last version
* Added dmi-basd hardware detection, and modparam
  override for it
* replaced DRIVER_NAME with KBUILD_MODNAME

--

This code is based on a driver that came in the "Open-source
and GPL components" download here:

http://downloadcenter.intel.com/SearchResult.aspx?lang=eng&ProductFamily=Server+Products&ProductLine=Intel%C2%AE+Storage+Systems&ProductProduct=Intel%C2%AE+Entry+Storage+System+SS4200-E&OSVersion=OS+Independent

It was in a file called nasgpio.c inside of a second zip file.

That code used an ioctl() call to operate the LEDs.  It also
created a new top-level /proc file just to let userspace locate
which dynamic major number had been allocated to the device.
Lovely.

I ripped out all of the hardware monitor support from nasgpio.c
as well as the smbus code that controls the LED brightness.  I
then converted the code to use the existing LED interfaces
rather than the ioctl().

Except for the probe routines, I rewrote most of it.

Thanks go to Arjan for his help in getting the original source
for this released and for chasing down some licensing issues.

Signed-off-by: Dave Hansen <dave@...1.net>
---
 drivers/leds/Kconfig       |    9 +
 drivers/leds/Makefile      |    1 +
 drivers/leds/leds-ss4200.c |  551 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 561 insertions(+), 0 deletions(-)
 create mode 100644 drivers/leds/leds-ss4200.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 7c8e712..ae6ed6e 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -229,6 +229,15 @@ config LEDS_BD2802
 	  This option enables support for BD2802GU RGB LED driver chips
 	  accessed via the I2C bus.
 
+config LEDS_INTEL_SS4200
+	tristate "LED driver for Intel NAS SS4200 series"
+	depends on LEDS_CLASS && PCI
+	help
+	  This option enables support for the Intel SS4200 series of
+	  Network Attached Storage servers.  You may control the hard
+	  drive or power LEDs on the front panel.  Using this driver
+	  can stop the front LED from blinking after startup.
+
 comment "LED Triggers"
 
 config LEDS_TRIGGERS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index e8cdcf7..6af2f99 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_LEDS_PCA955X)		+= leds-pca955x.o
 obj-$(CONFIG_LEDS_DA903X)		+= leds-da903x.o
 obj-$(CONFIG_LEDS_WM8350)		+= leds-wm8350.o
 obj-$(CONFIG_LEDS_PWM)			+= leds-pwm.o
+obj-$(CONFIG_LEDS_INTEL_SS4200)		+= leds-ss4200.o
 
 # LED SPI Drivers
 obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o
diff --git a/drivers/leds/leds-ss4200.c b/drivers/leds/leds-ss4200.c
new file mode 100644
index 0000000..9f0c2ad
--- /dev/null
+++ b/drivers/leds/leds-ss4200.c
@@ -0,0 +1,551 @@
+/*
+ * SS4200-E Hardware API
+ * Copyright (c) 2009, Intel Corporation.
+ * Copyright IBM Corporation, 2009
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Author: Dave Hansen <dave@...1.net>
+ */
+
+#include <linux/dmi.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+
+MODULE_AUTHOR("Rodney Girod <rgirod@...focus.com>, Dave Hansen <dave@...1.net>");
+MODULE_DESCRIPTION("Intel NAS/Home Server ICH7 GPIO Driver");
+MODULE_LICENSE("GPL");
+
+/*
+ * ICH7 LPC/GPIO PCI Config register offsets
+ */
+#define PMBASE		0x040
+#define GPIO_BASE	0x048
+#define GPIO_CTRL	0x04c
+#define GPIO_EN		0x010
+
+/*
+ * The ICH7 GPIO register block is 64 bytes in size.
+ */
+#define ICH7_GPIO_SIZE	64
+
+/*
+ * Define register offsets within the ICH7 register block.
+ */
+#define GPIO_USE_SEL	0x000
+#define GP_IO_SEL	0x004
+#define GP_LVL		0x00c
+#define GPO_BLINK	0x018
+#define GPI_INV		0x030
+#define GPIO_USE_SEL2	0x034
+#define GP_IO_SEL2	0x038
+#define GP_LVL2		0x03c
+
+/*
+ * PCI ID of the Intel ICH7 LPC Device within which the GPIO block lives.
+ */
+static struct pci_device_id ich7_lpc_pci_id[] =
+{
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_0) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_1) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_30) },
+	{ } /* NULL entry */
+};
+
+MODULE_DEVICE_TABLE(pci, ich7_lpc_pci_id);
+
+static int __init ss4200_led_dmi_callback(const struct dmi_system_id *id)
+{
+	printk(KERN_INFO KBUILD_MODNAME ": '%s' found\n", id->ident);
+	return 1;
+}
+
+static unsigned int __initdata nodetect;
+module_param_named(nodetect, nodetect, bool, 0);
+MODULE_PARM_DESC(nodetect, "Skip DMI-based hardware detection");
+
+/*
+ * struct nas_led_whitelist - List of known good models
+ *
+ * Contains the known good models this driver is compatible with.
+ * When adding a new model try to be as strict as possible. This
+ * makes it possible to keep the false positives (the model is
+ * detected as working, but in reality it is not) as low as
+ * possible.
+ */
+static struct dmi_system_id __initdata nas_led_whitelist[] = {
+	{
+		.callback = ss4200_led_dmi_callback,
+		.ident = "Intel SS4200-E",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Intel"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "SS4200-E"),
+			DMI_MATCH(DMI_PRODUCT_VERSION, "1.00.00")
+		}
+	},
+};
+ 
+/*
+ * Base I/O address assigned to the Power Management register block
+ */
+static u32 g_pm_io_base;
+
+/*
+ * Base I/O address assigned to the ICH7 GPIO register block
+ */
+static u32 nas_gpio_io_base;
+
+/*
+ * When we successfully register a region, we are returned a resource.
+ * We use these to identify which regions we need to release on our way
+ * back out.
+ */
+static struct resource *gp_gpio_resource;
+
+struct nasgpio_led {
+	char *name;
+	u32 gpio_bit;
+	struct led_classdev led_cdev;
+};
+
+/*
+ * gpio_bit(s) are the ICH7 GPIO bit assignments
+ */
+static struct nasgpio_led nasgpio_leds[] = {
+	{ .name = "hdd1:blue:sata",	.gpio_bit = 0 },
+	{ .name = "hdd1:amber:sata",	.gpio_bit = 1 },
+	{ .name = "hdd2:blue:sata",	.gpio_bit = 2 },
+	{ .name = "hdd2:amber:sata",	.gpio_bit = 3 },
+	{ .name = "hdd3:blue:sata",	.gpio_bit = 4 },
+	{ .name = "hdd3:amber:sata",	.gpio_bit = 5 },
+	{ .name = "hdd4:blue:sata",	.gpio_bit = 6 },
+	{ .name = "hdd4:amber:sata",	.gpio_bit = 7 },
+	{ .name = "power:blue:power",	.gpio_bit = 27},
+	{ .name = "power:amber:power",  .gpio_bit = 28},
+};
+
+#define NAS_RECOVERY	0x00000400	/* GPIO10 */
+
+static struct nasgpio_led *
+led_classdev_to_nasgpio_led(struct led_classdev *led_cdev)
+{
+	return container_of(led_cdev, struct nasgpio_led, led_cdev);
+}
+
+static struct nasgpio_led *get_led_named(char *name)
+{
+	int i;
+	for (i = 0; i < ARRAY_SIZE(nasgpio_leds); i++) {
+		if (strcmp(nasgpio_leds[i].name, name))
+			continue;
+		return &nasgpio_leds[i];
+	}
+	return NULL;
+}
+
+/*
+ * This protects access to the gpio ports.
+ */
+static DEFINE_SPINLOCK(nasgpio_gpio_lock);
+
+/*
+ * There are two gpio ports, one for blinking and the other
+ * for power.  @port tells us if we're doing blinking or
+ * power control.
+ *
+ * Caller must hold nasgpio_gpio_lock
+ */
+void nasgpio_led_set_attr(struct led_classdev *led_cdev, u32 port, u32 value)
+{
+	struct nasgpio_led *led = led_classdev_to_nasgpio_led(led_cdev);
+	u32 gpio_out;
+
+	gpio_out = inl(nas_gpio_io_base + port);
+	if (value)
+		gpio_out |= (1<<led->gpio_bit);
+	else
+		gpio_out &= ~(1<<led->gpio_bit);
+
+	outl(gpio_out, nas_gpio_io_base + port);
+}
+
+u32 nasgpio_led_get_attr(struct led_classdev *led_cdev, u32 port)
+{
+	struct nasgpio_led *led = led_classdev_to_nasgpio_led(led_cdev);
+	u32 gpio_in;
+
+	spin_lock(&nasgpio_gpio_lock);
+	gpio_in = inl(nas_gpio_io_base + port);
+	spin_unlock(&nasgpio_gpio_lock);
+	if (gpio_in & (1<<led->gpio_bit))
+		return 1;
+	return 0;
+}
+
+/*
+ * There is actual brightness control in the hardware,
+ * but it is via smbus commands and not implemented
+ * in this driver.
+ */
+static void nasgpio_led_set_brightness(struct led_classdev *led_cdev,
+				       enum led_brightness brightness)
+{
+	u32 setting = 0;
+	if (brightness >= LED_HALF)
+		setting = 1;
+	/*
+	 * Hold the lock across both operations.  This ensures
+	 * consistency so that both the "turn off blinking"
+	 * and "turn light off" operations complete as a set.
+	 */
+	spin_lock(&nasgpio_gpio_lock);
+	/*
+	 * LED class documentation asks that past blink state
+	 * be disabled when brightness is turned to zero.
+	 */
+	if (brightness == 0)
+		nasgpio_led_set_attr(led_cdev, GPO_BLINK, 0);
+	nasgpio_led_set_attr(led_cdev, GP_LVL, setting);
+	spin_unlock(&nasgpio_gpio_lock);
+}
+
+static int nasgpio_led_set_blink(struct led_classdev *led_cdev,
+				 unsigned long *delay_on,
+				 unsigned long *delay_off)
+{
+	u32 setting = 1;
+	if (!(*delay_on == 0 && *delay_off == 0) &&
+	    !(*delay_on == 500 && *delay_off == 500))
+		return -EINVAL;
+	/*
+	 * These are very approximate.
+	 */
+	*delay_on = 500;
+	*delay_off = 500;
+
+	spin_lock(&nasgpio_gpio_lock);
+	nasgpio_led_set_attr(led_cdev, GPO_BLINK, setting);
+	spin_unlock(&nasgpio_gpio_lock);
+
+	return 0;
+}
+
+
+/*
+ * Initialize the ICH7 GPIO registers for NAS usage.  The BIOS should have
+ * already taken care of this, but we will do so in a non destructive manner
+ * so that we have what we need whether the BIOS did it or not.
+ */
+static int ich7_gpio_init(struct device *dev)
+{
+	int i;
+	u32 config_data = 0;
+	u32 all_nas_led = 0;
+
+	for (i = 0; i < ARRAY_SIZE(nasgpio_leds); i++)
+		all_nas_led |= (1<<nasgpio_leds[i].gpio_bit);
+
+	spin_lock(&nasgpio_gpio_lock);
+	/*
+	 * We need to enable all of the GPIO lines used by the NAS box,
+	 * so we will read the current Use Selection and add our usage
+	 * to it.  This should be benign with regard to the original
+	 * BIOS configuration.
+	 */
+	config_data = inl(nas_gpio_io_base + GPIO_USE_SEL);
+	dev_printk(KERN_DEBUG, dev, "Data read from GPIO_USE_SEL = 0x%08x\n",
+					config_data);
+	config_data |= all_nas_led + NAS_RECOVERY;
+	outl(config_data, nas_gpio_io_base + GPIO_USE_SEL);
+	config_data = inl(nas_gpio_io_base + GPIO_USE_SEL);
+	dev_printk(KERN_DEBUG, dev, "GPIO_USE_SEL = 0x%08x\n\n",
+					config_data);
+
+	/*
+	 * The LED GPIO outputs need to be configured for output, so we
+	 * will ensure that all LED lines are cleared for output and the
+	 * RECOVERY line ready for input.  This too should be benign with
+	 * regard to BIOS configuration.
+	 */
+	config_data = inl(nas_gpio_io_base + GP_IO_SEL);
+	dev_printk(KERN_DEBUG, dev, "Data read from GP_IO_SEL = 0x%08x\n",
+					config_data);
+	config_data &= ~all_nas_led;
+	config_data |= NAS_RECOVERY;
+	outl(config_data, nas_gpio_io_base + GP_IO_SEL);
+	config_data = inl(nas_gpio_io_base + GP_IO_SEL);
+	dev_printk(KERN_DEBUG, dev, "GP_IO_SEL = 0x%08x\n\n",
+					config_data);
+
+	/*
+	 * In our final system, the BIOS will initialize the state of all
+	 * of the LEDs.  For now, we turn them all off (or Low).
+	 */
+	config_data = inl(nas_gpio_io_base + GP_LVL);
+	dev_printk(KERN_DEBUG, dev, "Data read from GP_LVL = 0x%08x\n",
+				   config_data);
+	/*
+	 * In our final system, the BIOS will initialize the blink state of all
+	 * of the LEDs.  For now, we turn blink off for all of them.
+	 */
+	config_data = inl(nas_gpio_io_base + GPO_BLINK);
+	dev_printk(KERN_DEBUG, dev, "Data read from GPO_BLINK = 0x%08x\n",
+					config_data);
+
+	/*
+	 * At this moment, I am unsure if anything needs to happen with GPI_INV
+	 */
+	config_data = inl(nas_gpio_io_base + GPI_INV);
+	dev_printk(KERN_DEBUG, dev, "Data read from GPI_INV = 0x%08x\n",
+					config_data);
+
+	spin_unlock(&nasgpio_gpio_lock);
+	return 0;
+}
+
+static void ich7_lpc_cleanup(struct device *dev)
+{
+	/*
+	 * If we were given exclusive use of the GPIO
+	 * I/O Address range, we must return it.
+	 */
+	if (gp_gpio_resource) {
+		dev_printk(KERN_DEBUG, dev, "Releasing GPIO I/O addresses\n");
+		release_region(nas_gpio_io_base, ICH7_GPIO_SIZE);
+		gp_gpio_resource = NULL;
+	}
+}
+
+/*
+ * The OS has determined that the LPC of the Intel ICH7 Southbridge is present
+ * so we can retrive the required operational information and prepare the GPIO.
+ */
+static struct pci_dev *nas_gpio_pci_dev;
+static int ich7_lpc_probe(struct pci_dev *dev, const struct pci_device_id *id)
+{
+	int status = 0;
+	u32 gc = 0;
+
+	pci_enable_device(dev);
+
+	nas_gpio_pci_dev = dev;
+	status = pci_read_config_dword(dev, PMBASE, &g_pm_io_base);
+	if (status)
+		goto out;
+	g_pm_io_base &= 0x00000ff80;
+
+	status = pci_read_config_dword(dev, GPIO_CTRL, &gc);
+	if (!(GPIO_EN & gc)) {
+		status = -EEXIST;
+		dev_printk(KERN_INFO, &dev->dev,
+			   "ERROR: The LPC GPIO Block has not been enabled.\n");
+		goto out;
+	}
+
+	status = pci_read_config_dword(dev, GPIO_BASE, &nas_gpio_io_base);
+	if (0 > status) {
+		dev_printk(KERN_INFO, &dev->dev, "Unable to read GPIOBASE.\n");
+		goto out;
+	}
+	dev_printk(KERN_DEBUG, &dev->dev,
+		   "GPIOBASE = 0x%08x\n", nas_gpio_io_base);
+	nas_gpio_io_base &= 0x00000ffc0;
+
+	/*
+	 * Insure that we have exclusive access to the GPIO I/O address range.
+	 */
+	gp_gpio_resource = request_region(nas_gpio_io_base,
+					  ICH7_GPIO_SIZE, KBUILD_MODNAME);
+	if (NULL == gp_gpio_resource) {
+		dev_printk(KERN_INFO, &dev->dev,
+			   "ERROR Unable to register GPIO I/O addresses.\n");
+		status = -1;
+		goto out;
+	}
+
+	/*
+	 * Initialize the GPIO for NAS/Home Server Use
+	 */
+	ich7_gpio_init(&dev->dev);
+
+out:
+	if (status)
+		ich7_lpc_cleanup(&dev->dev);
+	return status;
+}
+
+static void ich7_lpc_remove(struct pci_dev *dev)
+{
+	ich7_lpc_cleanup(&dev->dev);
+}
+
+/*
+ * pci_driver structure passed to the PCI modules
+ */
+static struct pci_driver nas_gpio_pci_driver = {
+	.name = KBUILD_MODNAME,
+	.id_table = ich7_lpc_pci_id,
+	.probe = ich7_lpc_probe,
+	.remove = ich7_lpc_remove,
+};
+
+static struct led_classdev *get_classdev_for_led_nr(int nr)
+{
+	struct nasgpio_led *nas_led = &nasgpio_leds[nr];
+	struct led_classdev *led = &nas_led->led_cdev;
+	return led;
+}
+
+
+void set_power_light_amber_noblink(void)
+{
+	struct nasgpio_led *amber = get_led_named("power:amber:power");
+	struct nasgpio_led *blue = get_led_named("power:blue:power");
+
+	if (!amber || !blue)
+		return;
+	/*
+	 * LED_OFF implies disabling future blinking
+	 */
+	printk(KERN_DEBUG "setting blue off and amber on\n");
+
+	nasgpio_led_set_brightness(&blue->led_cdev, LED_OFF);
+	nasgpio_led_set_brightness(&amber->led_cdev, LED_FULL);
+}
+
+static ssize_t nas_led_blink_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *led = dev_get_drvdata(dev);
+	int blinking = 0;
+	if (nasgpio_led_get_attr(led, GPO_BLINK))
+		blinking = 1;
+	return sprintf(buf, "%u\n", blinking);
+}
+
+static ssize_t nas_led_blink_store(struct device *dev,
+				   struct device_attribute *attr,
+				   const char *buf, size_t size)
+{
+	int ret;
+	struct led_classdev *led = dev_get_drvdata(dev);
+	unsigned long blink_state;
+
+	ret = strict_strtoul(buf, 10, &blink_state);
+	if (ret)
+		return ret;
+
+	spin_lock(&nasgpio_gpio_lock);
+	nasgpio_led_set_attr(led, GPO_BLINK, blink_state);
+	spin_unlock(&nasgpio_gpio_lock);
+
+	return size;
+}
+
+static DEVICE_ATTR(blink, 0644, nas_led_blink_show, nas_led_blink_store);
+
+int register_nasgpio_led(int led_nr)
+{
+	int ret;
+	struct nasgpio_led *nas_led = &nasgpio_leds[led_nr];
+	struct led_classdev *led = get_classdev_for_led_nr(led_nr);
+
+	led->name = nas_led->name;
+	led->brightness = LED_OFF;
+	if (nasgpio_led_get_attr(led, GP_LVL))
+		led->brightness = LED_FULL;
+	led->brightness_set = nasgpio_led_set_brightness;
+	led->blink_set = nasgpio_led_set_blink;
+	ret = led_classdev_register(&nas_gpio_pci_dev->dev, led);
+	if (ret)
+		return ret;
+	ret = device_create_file(led->dev, &dev_attr_blink);
+	if (ret)
+		led_classdev_unregister(led);
+	return ret;
+}
+
+void unregister_nasgpio_led(int led_nr)
+{
+	struct led_classdev *led = get_classdev_for_led_nr(led_nr);
+	led_classdev_unregister(led);
+	device_remove_file(led->dev, &dev_attr_blink);
+}
+/*
+ * module load/initialization
+ */
+static int __init nas_gpio_init(void)
+{
+	int i;
+	int ret = 0;
+	int nr_devices = 0;
+
+	nr_devices = dmi_check_system(nas_led_whitelist);
+	if (nodetect) {
+		printk(KERN_INFO "%s: skipping hardware autodetection\n",
+				KBUILD_MODNAME);
+		printk(KERN_INFO "\tif this works, please send the output ");
+		printk(KERN_INFO "of 'dmidecode' to dave@...1.net\n");
+		nr_devices++;
+	}
+
+	if (nr_devices <= 0) {
+		printk(KERN_INFO "%s: no LED devices found\n",
+				KBUILD_MODNAME);
+		return -ENODEV;
+	}
+
+	printk(KERN_INFO "registering %s PCI driver\n", KBUILD_MODNAME);
+	ret = pci_register_driver(&nas_gpio_pci_driver);
+	if (ret)
+		return ret;
+	for (i = 0; i < ARRAY_SIZE(nasgpio_leds); i++) {
+		ret = register_nasgpio_led(i);
+		if (ret)
+			goto out_err;
+	}
+	/*
+	 * When the system powers on, the BIOS leaves the power
+	 * light blue and blinking.  This will turn it solid
+	 * amber once the driver is loaded.
+	 */
+	set_power_light_amber_noblink();
+	return 0;
+out_err:
+	for (; i >= 0; i--)
+		unregister_nasgpio_led(i);
+	pci_unregister_driver(&nas_gpio_pci_driver);
+	return ret;
+}
+
+/*
+ * module unload
+ */
+static void __exit nas_gpio_exit(void)
+{
+	int i;
+	printk(KERN_INFO "Unregistering %s driver\n", KBUILD_MODNAME);
+	for (i = 0; i < ARRAY_SIZE(nasgpio_leds); i++)
+		unregister_nasgpio_led(i);
+	pci_unregister_driver(&nas_gpio_pci_driver);
+}
+
+module_init(nas_gpio_init);
+module_exit(nas_gpio_exit);
-- 
1.6.5.rc1.13.g2b621c

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