hwmon: (sch5627) Factor out some code shared with sch5636 driver

This patch adds a new sch56xx-common.ko which contains code which will also
be used in the new sch5636 driver.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 336 insertions, 0 deletions

diff --git a/drivers/hwmon/sch56xx-common.c b/drivers/hwmon/sch56xx-common.c
new file mode 100644
index 000000000000..a579313b55df
--- /dev/null
+++ b/drivers/hwmon/sch56xx-common.c
@@ -0,0 +1,336 @@
+/***************************************************************************
+ *   Copyright (C) 2010-2011 Hans de Goede <hdegoede@redhat.com>           *
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program is distributed in the hope that 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.,                                       *
+ *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
+ ***************************************************************************/
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include "sch56xx-common.h"
+
+#define SIO_SCH56XX_LD_EM	0x0C	/* Embedded uController Logical Dev */
+#define SIO_UNLOCK_KEY		0x55	/* Key to enable Super-I/O */
+#define SIO_LOCK_KEY		0xAA	/* Key to disable Super-I/O */
+
+#define SIO_REG_LDSEL		0x07	/* Logical device select */
+#define SIO_REG_DEVID		0x20	/* Device ID */
+#define SIO_REG_ENABLE		0x30	/* Logical device enable */
+#define SIO_REG_ADDR		0x66	/* Logical device address (2 bytes) */
+
+#define SIO_SCH5627_ID		0xC6	/* Chipset ID */
+
+#define REGION_LENGTH		9
+
+#define SCH56XX_CMD_READ	0x02
+#define SCH56XX_CMD_WRITE	0x03
+
+static struct platform_device *sch56xx_pdev;
+
+/* Super I/O functions */
+static inline int superio_inb(int base, int reg)
+{
+	outb(reg, base);
+	return inb(base + 1);
+}
+
+static inline int superio_enter(int base)
+{
+	/* Don't step on other drivers' I/O space by accident */
+	if (!request_muxed_region(base, 2, "sch56xx")) {
+		pr_err("I/O address 0x%04x already in use\n", base);
+		return -EBUSY;
+	}
+
+	outb(SIO_UNLOCK_KEY, base);
+
+	return 0;
+}
+
+static inline void superio_select(int base, int ld)
+{
+	outb(SIO_REG_LDSEL, base);
+	outb(ld, base + 1);
+}
+
+static inline void superio_exit(int base)
+{
+	outb(SIO_LOCK_KEY, base);
+	release_region(base, 2);
+}
+
+static int sch56xx_send_cmd(u16 addr, u8 cmd, u16 reg, u8 v)
+{
+	u8 val;
+	int i;
+	/*
+	 * According to SMSC for the commands we use the maximum time for
+	 * the EM to respond is 15 ms, but testing shows in practice it
+	 * responds within 15-32 reads, so we first busy poll, and if
+	 * that fails sleep a bit and try again until we are way past
+	 * the 15 ms maximum response time.
+	 */
+	const int max_busy_polls = 64;
+	const int max_lazy_polls = 32;
+
+	/* (Optional) Write-Clear the EC to Host Mailbox Register */
+	val = inb(addr + 1);
+	outb(val, addr + 1);
+
+	/* Set Mailbox Address Pointer to first location in Region 1 */
+	outb(0x00, addr + 2);
+	outb(0x80, addr + 3);
+
+	/* Write Request Packet Header */
+	outb(cmd, addr + 4); /* VREG Access Type read:0x02 write:0x03 */
+	outb(0x01, addr + 5); /* # of Entries: 1 Byte (8-bit) */
+	outb(0x04, addr + 2); /* Mailbox AP to first data entry loc. */
+
+	/* Write Value field */
+	if (cmd == SCH56XX_CMD_WRITE)
+		outb(v, addr + 4);
+
+	/* Write Address field */
+	outb(reg & 0xff, addr + 6);
+	outb(reg >> 8, addr + 7);
+
+	/* Execute the Random Access Command */
+	outb(0x01, addr); /* Write 01h to the Host-to-EC register */
+
+	/* EM Interface Polling "Algorithm" */
+	for (i = 0; i < max_busy_polls + max_lazy_polls; i++) {
+		if (i >= max_busy_polls)
+			msleep(1);
+		/* Read Interrupt source Register */
+		val = inb(addr + 8);
+		/* Write Clear the interrupt source bits */
+		if (val)
+			outb(val, addr + 8);
+		/* Command Completed ? */
+		if (val & 0x01)
+			break;
+	}
+	if (i == max_busy_polls + max_lazy_polls) {
+		pr_err("Max retries exceeded reading virtual "
+		       "register 0x%04hx (%d)\n", reg, 1);
+		return -EIO;
+	}
+
+	/*
+	 * According to SMSC we may need to retry this, but sofar I've always
+	 * seen this succeed in 1 try.
+	 */
+	for (i = 0; i < max_busy_polls; i++) {
+		/* Read EC-to-Host Register */
+		val = inb(addr + 1);
+		/* Command Completed ? */
+		if (val == 0x01)
+			break;
+
+		if (i == 0)
+			pr_warn("EC reports: 0x%02x reading virtual register "
+				"0x%04hx\n", (unsigned int)val, reg);
+	}
+	if (i == max_busy_polls) {
+		pr_err("Max retries exceeded reading virtual "
+		       "register 0x%04hx (%d)\n", reg, 2);
+		return -EIO;
+	}
+
+	/*
+	 * According to the SMSC app note we should now do:
+	 *
+	 * Set Mailbox Address Pointer to first location in Region 1 *
+	 * outb(0x00, addr + 2);
+	 * outb(0x80, addr + 3);
+	 *
+	 * But if we do that things don't work, so let's not.
+	 */
+
+	/* Read Value field */
+	if (cmd == SCH56XX_CMD_READ)
+		return inb(addr + 4);
+
+	return 0;
+}
+
+int sch56xx_read_virtual_reg(u16 addr, u16 reg)
+{
+	return sch56xx_send_cmd(addr, SCH56XX_CMD_READ, reg, 0);
+}
+EXPORT_SYMBOL(sch56xx_read_virtual_reg);
+
+int sch56xx_write_virtual_reg(u16 addr, u16 reg, u8 val)
+{
+	return sch56xx_send_cmd(addr, SCH56XX_CMD_WRITE, reg, val);
+}
+EXPORT_SYMBOL(sch56xx_write_virtual_reg);
+
+int sch56xx_read_virtual_reg16(u16 addr, u16 reg)
+{
+	int lsb, msb;
+
+	/* Read LSB first, this will cause the matching MSB to be latched */
+	lsb = sch56xx_read_virtual_reg(addr, reg);
+	if (lsb < 0)
+		return lsb;
+
+	msb = sch56xx_read_virtual_reg(addr, reg + 1);
+	if (msb < 0)
+		return msb;
+
+	return lsb | (msb << 8);
+}
+EXPORT_SYMBOL(sch56xx_read_virtual_reg16);
+
+int sch56xx_read_virtual_reg12(u16 addr, u16 msb_reg, u16 lsn_reg,
+			       int high_nibble)
+{
+	int msb, lsn;
+
+	/* Read MSB first, this will cause the matching LSN to be latched */
+	msb = sch56xx_read_virtual_reg(addr, msb_reg);
+	if (msb < 0)
+		return msb;
+
+	lsn = sch56xx_read_virtual_reg(addr, lsn_reg);
+	if (lsn < 0)
+		return lsn;
+
+	if (high_nibble)
+		return (msb << 4) | (lsn >> 4);
+	else
+		return (msb << 4) | (lsn & 0x0f);
+}
+EXPORT_SYMBOL(sch56xx_read_virtual_reg12);
+
+static int __init sch56xx_find(int sioaddr, unsigned short *address,
+			       const char **name)
+{
+	u8 devid;
+	int err;
+
+	err = superio_enter(sioaddr);
+	if (err)
+		return err;
+
+	devid = superio_inb(sioaddr, SIO_REG_DEVID);
+	switch (devid) {
+	case SIO_SCH5627_ID:
+		*name = "sch5627";
+		break;
+	default:
+		pr_debug("Unsupported device id: 0x%02x\n",
+			 (unsigned int)devid);
+		err = -ENODEV;
+		goto exit;
+	}
+
+	superio_select(sioaddr, SIO_SCH56XX_LD_EM);
+
+	if (!(superio_inb(sioaddr, SIO_REG_ENABLE) & 0x01)) {
+		pr_warn("Device not activated\n");
+		err = -ENODEV;
+		goto exit;
+	}
+
+	/*
+	 * Warning the order of the low / high byte is the other way around
+	 * as on most other superio devices!!
+	 */
+	*address = superio_inb(sioaddr, SIO_REG_ADDR) |
+		   superio_inb(sioaddr, SIO_REG_ADDR + 1) << 8;
+	if (*address == 0) {
+		pr_warn("Base address not set\n");
+		err = -ENODEV;
+		goto exit;
+	}
+
+exit:
+	superio_exit(sioaddr);
+	return err;
+}
+
+static int __init sch56xx_device_add(unsigned short address, const char *name)
+{
+	struct resource res = {
+		.start	= address,
+		.end	= address + REGION_LENGTH - 1,
+		.flags	= IORESOURCE_IO,
+	};
+	int err;
+
+	sch56xx_pdev = platform_device_alloc(name, address);
+	if (!sch56xx_pdev)
+		return -ENOMEM;
+
+	res.name = sch56xx_pdev->name;
+	err = acpi_check_resource_conflict(&res);
+	if (err)
+		goto exit_device_put;
+
+	err = platform_device_add_resources(sch56xx_pdev, &res, 1);
+	if (err) {
+		pr_err("Device resource addition failed\n");
+		goto exit_device_put;
+	}
+
+	err = platform_device_add(sch56xx_pdev);
+	if (err) {
+		pr_err("Device addition failed\n");
+		goto exit_device_put;
+	}
+
+	return 0;
+
+exit_device_put:
+	platform_device_put(sch56xx_pdev);
+
+	return err;
+}
+
+static int __init sch56xx_init(void)
+{
+	int err;
+	unsigned short address;
+	const char *name;
+
+	err = sch56xx_find(0x4e, &address, &name);
+	if (err)
+		err = sch56xx_find(0x2e, &address, &name);
+	if (err)
+		return err;
+
+	return sch56xx_device_add(address, name);
+}
+
+static void __exit sch56xx_exit(void)
+{
+	platform_device_unregister(sch56xx_pdev);
+}
+
+MODULE_DESCRIPTION("SMSC SCH56xx Hardware Monitoring Common Code");
+MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
+MODULE_LICENSE("GPL");
+
+module_init(sch56xx_init);
+module_exit(sch56xx_exit);