Message-Id: <1253047135.10449.11657.camel@nimitz>
Date:	Tue, 15 Sep 2009 13:38:55 -0700
From:	Dave Hansen <dave@...1.net>
To:	Richard Purdie <rpurdie@...ys.net>
Cc:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Arjan van de Ven <arjan@...radead.org>
Subject: [RFC][PATCH] LED driver for Intel NAS SS4200 series

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
called SS4200-E_Linux_SIO_Driver-v1.4.zip.

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.
I decided that the interface probably wasn't mergeable in that
form. :)
    
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().  I don't have any need for brightness
control, and its code is *completely* separate from the on/off
controls implemented here.  If anyone else wants it, I'd be
happy to look into adding it, but I don't care enough for now.

Except for the probe routines, I rewrote most of it.  I also
Note that I don't have any hardware documentation except for
the original driver.  

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>

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..95d7796
--- /dev/null
+++ b/drivers/leds/leds-ss4200.c
@@ -0,0 +1,506 @@
+/*********************************************************
+ *
+/*
+ * 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/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");
+
+#define DRIVER_NAME (THIS_MODULE->name)
+
+/*
+ * 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);
+
+/*
+ * 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, DRIVER_NAME);
+	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 = DRIVER_NAME,
+	.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);
+	device_remove_file(led->dev, &dev_attr_blink);
+}
+/*
+ * module load/initialization
+ */
+static int __init nas_gpio_init(void)
+{
+	int i;
+	int ret = 0;
+
+	printk(KERN_INFO "registering %s driver\n", DRIVER_NAME);
+	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", DRIVER_NAME);
+	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);

-- Dave

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