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);