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576 lines
14 KiB
576 lines
14 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/*************************************************************************** |
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* Copyright (C) 2010-2012 Hans de Goede <[email protected]> * |
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* * |
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***************************************************************************/ |
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/module.h> |
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#include <linux/init.h> |
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#include <linux/platform_device.h> |
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#include <linux/err.h> |
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#include <linux/io.h> |
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#include <linux/acpi.h> |
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#include <linux/delay.h> |
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#include <linux/fs.h> |
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#include <linux/watchdog.h> |
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#include <linux/uaccess.h> |
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#include <linux/slab.h> |
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#include "sch56xx-common.h" |
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/* Insmod parameters */ |
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static int nowayout = WATCHDOG_NOWAYOUT; |
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module_param(nowayout, int, 0); |
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" |
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
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#define SIO_SCH56XX_LD_EM 0x0C /* Embedded uController Logical Dev */ |
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#define SIO_UNLOCK_KEY 0x55 /* Key to enable Super-I/O */ |
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#define SIO_LOCK_KEY 0xAA /* Key to disable Super-I/O */ |
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#define SIO_REG_LDSEL 0x07 /* Logical device select */ |
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#define SIO_REG_DEVID 0x20 /* Device ID */ |
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#define SIO_REG_ENABLE 0x30 /* Logical device enable */ |
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#define SIO_REG_ADDR 0x66 /* Logical device address (2 bytes) */ |
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#define SIO_SCH5627_ID 0xC6 /* Chipset ID */ |
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#define SIO_SCH5636_ID 0xC7 /* Chipset ID */ |
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#define REGION_LENGTH 10 |
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#define SCH56XX_CMD_READ 0x02 |
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#define SCH56XX_CMD_WRITE 0x03 |
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/* Watchdog registers */ |
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#define SCH56XX_REG_WDOG_PRESET 0x58B |
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#define SCH56XX_REG_WDOG_CONTROL 0x58C |
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#define SCH56XX_WDOG_TIME_BASE_SEC 0x01 |
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#define SCH56XX_REG_WDOG_OUTPUT_ENABLE 0x58E |
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#define SCH56XX_WDOG_OUTPUT_ENABLE 0x02 |
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struct sch56xx_watchdog_data { |
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u16 addr; |
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struct mutex *io_lock; |
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struct watchdog_info wdinfo; |
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struct watchdog_device wddev; |
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u8 watchdog_preset; |
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u8 watchdog_control; |
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u8 watchdog_output_enable; |
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}; |
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static struct platform_device *sch56xx_pdev; |
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/* Super I/O functions */ |
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static inline int superio_inb(int base, int reg) |
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{ |
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outb(reg, base); |
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return inb(base + 1); |
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} |
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static inline int superio_enter(int base) |
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{ |
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/* Don't step on other drivers' I/O space by accident */ |
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if (!request_muxed_region(base, 2, "sch56xx")) { |
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pr_err("I/O address 0x%04x already in use\n", base); |
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return -EBUSY; |
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} |
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outb(SIO_UNLOCK_KEY, base); |
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return 0; |
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} |
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static inline void superio_select(int base, int ld) |
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{ |
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outb(SIO_REG_LDSEL, base); |
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outb(ld, base + 1); |
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} |
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static inline void superio_exit(int base) |
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{ |
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outb(SIO_LOCK_KEY, base); |
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release_region(base, 2); |
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} |
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static int sch56xx_send_cmd(u16 addr, u8 cmd, u16 reg, u8 v) |
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{ |
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u8 val; |
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int i; |
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/* |
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* According to SMSC for the commands we use the maximum time for |
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* the EM to respond is 15 ms, but testing shows in practice it |
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* responds within 15-32 reads, so we first busy poll, and if |
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* that fails sleep a bit and try again until we are way past |
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* the 15 ms maximum response time. |
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*/ |
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const int max_busy_polls = 64; |
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const int max_lazy_polls = 32; |
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/* (Optional) Write-Clear the EC to Host Mailbox Register */ |
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val = inb(addr + 1); |
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outb(val, addr + 1); |
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/* Set Mailbox Address Pointer to first location in Region 1 */ |
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outb(0x00, addr + 2); |
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outb(0x80, addr + 3); |
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/* Write Request Packet Header */ |
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outb(cmd, addr + 4); /* VREG Access Type read:0x02 write:0x03 */ |
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outb(0x01, addr + 5); /* # of Entries: 1 Byte (8-bit) */ |
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outb(0x04, addr + 2); /* Mailbox AP to first data entry loc. */ |
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/* Write Value field */ |
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if (cmd == SCH56XX_CMD_WRITE) |
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outb(v, addr + 4); |
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/* Write Address field */ |
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outb(reg & 0xff, addr + 6); |
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outb(reg >> 8, addr + 7); |
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/* Execute the Random Access Command */ |
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outb(0x01, addr); /* Write 01h to the Host-to-EC register */ |
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/* EM Interface Polling "Algorithm" */ |
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for (i = 0; i < max_busy_polls + max_lazy_polls; i++) { |
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if (i >= max_busy_polls) |
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msleep(1); |
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/* Read Interrupt source Register */ |
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val = inb(addr + 8); |
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/* Write Clear the interrupt source bits */ |
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if (val) |
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outb(val, addr + 8); |
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/* Command Completed ? */ |
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if (val & 0x01) |
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break; |
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} |
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if (i == max_busy_polls + max_lazy_polls) { |
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pr_err("Max retries exceeded reading virtual register 0x%04hx (%d)\n", |
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reg, 1); |
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return -EIO; |
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} |
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/* |
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* According to SMSC we may need to retry this, but sofar I've always |
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* seen this succeed in 1 try. |
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*/ |
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for (i = 0; i < max_busy_polls; i++) { |
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/* Read EC-to-Host Register */ |
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val = inb(addr + 1); |
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/* Command Completed ? */ |
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if (val == 0x01) |
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break; |
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if (i == 0) |
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pr_warn("EC reports: 0x%02x reading virtual register 0x%04hx\n", |
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(unsigned int)val, reg); |
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} |
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if (i == max_busy_polls) { |
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pr_err("Max retries exceeded reading virtual register 0x%04hx (%d)\n", |
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reg, 2); |
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return -EIO; |
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} |
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/* |
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* According to the SMSC app note we should now do: |
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* |
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* Set Mailbox Address Pointer to first location in Region 1 * |
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* outb(0x00, addr + 2); |
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* outb(0x80, addr + 3); |
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* |
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* But if we do that things don't work, so let's not. |
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*/ |
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/* Read Value field */ |
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if (cmd == SCH56XX_CMD_READ) |
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return inb(addr + 4); |
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return 0; |
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} |
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int sch56xx_read_virtual_reg(u16 addr, u16 reg) |
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{ |
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return sch56xx_send_cmd(addr, SCH56XX_CMD_READ, reg, 0); |
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} |
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EXPORT_SYMBOL(sch56xx_read_virtual_reg); |
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int sch56xx_write_virtual_reg(u16 addr, u16 reg, u8 val) |
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{ |
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return sch56xx_send_cmd(addr, SCH56XX_CMD_WRITE, reg, val); |
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} |
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EXPORT_SYMBOL(sch56xx_write_virtual_reg); |
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int sch56xx_read_virtual_reg16(u16 addr, u16 reg) |
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{ |
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int lsb, msb; |
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/* Read LSB first, this will cause the matching MSB to be latched */ |
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lsb = sch56xx_read_virtual_reg(addr, reg); |
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if (lsb < 0) |
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return lsb; |
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msb = sch56xx_read_virtual_reg(addr, reg + 1); |
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if (msb < 0) |
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return msb; |
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return lsb | (msb << 8); |
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} |
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EXPORT_SYMBOL(sch56xx_read_virtual_reg16); |
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int sch56xx_read_virtual_reg12(u16 addr, u16 msb_reg, u16 lsn_reg, |
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int high_nibble) |
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{ |
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int msb, lsn; |
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/* Read MSB first, this will cause the matching LSN to be latched */ |
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msb = sch56xx_read_virtual_reg(addr, msb_reg); |
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if (msb < 0) |
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return msb; |
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lsn = sch56xx_read_virtual_reg(addr, lsn_reg); |
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if (lsn < 0) |
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return lsn; |
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if (high_nibble) |
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return (msb << 4) | (lsn >> 4); |
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else |
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return (msb << 4) | (lsn & 0x0f); |
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} |
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EXPORT_SYMBOL(sch56xx_read_virtual_reg12); |
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/* |
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* Watchdog routines |
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*/ |
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static int watchdog_set_timeout(struct watchdog_device *wddev, |
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unsigned int timeout) |
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{ |
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struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev); |
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unsigned int resolution; |
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u8 control; |
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int ret; |
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/* 1 second or 60 second resolution? */ |
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if (timeout <= 255) |
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resolution = 1; |
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else |
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resolution = 60; |
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if (timeout < resolution || timeout > (resolution * 255)) |
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return -EINVAL; |
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if (resolution == 1) |
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control = data->watchdog_control | SCH56XX_WDOG_TIME_BASE_SEC; |
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else |
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control = data->watchdog_control & ~SCH56XX_WDOG_TIME_BASE_SEC; |
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if (data->watchdog_control != control) { |
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mutex_lock(data->io_lock); |
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ret = sch56xx_write_virtual_reg(data->addr, |
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SCH56XX_REG_WDOG_CONTROL, |
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control); |
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mutex_unlock(data->io_lock); |
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if (ret) |
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return ret; |
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data->watchdog_control = control; |
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} |
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/* |
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* Remember new timeout value, but do not write as that (re)starts |
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* the watchdog countdown. |
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*/ |
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data->watchdog_preset = DIV_ROUND_UP(timeout, resolution); |
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wddev->timeout = data->watchdog_preset * resolution; |
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return 0; |
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} |
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static int watchdog_start(struct watchdog_device *wddev) |
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{ |
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struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev); |
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int ret; |
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u8 val; |
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/* |
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* The sch56xx's watchdog cannot really be started / stopped |
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* it is always running, but we can avoid the timer expiring |
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* from causing a system reset by clearing the output enable bit. |
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* |
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* The sch56xx's watchdog will set the watchdog event bit, bit 0 |
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* of the second interrupt source register (at base-address + 9), |
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* when the timer expires. |
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* |
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* This will only cause a system reset if the 0-1 flank happens when |
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* output enable is true. Setting output enable after the flank will |
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* not cause a reset, nor will the timer expiring a second time. |
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* This means we must clear the watchdog event bit in case it is set. |
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* |
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* The timer may still be running (after a recent watchdog_stop) and |
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* mere milliseconds away from expiring, so the timer must be reset |
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* first! |
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*/ |
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mutex_lock(data->io_lock); |
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/* 1. Reset the watchdog countdown counter */ |
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ret = sch56xx_write_virtual_reg(data->addr, SCH56XX_REG_WDOG_PRESET, |
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data->watchdog_preset); |
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if (ret) |
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goto leave; |
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/* 2. Enable output */ |
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val = data->watchdog_output_enable | SCH56XX_WDOG_OUTPUT_ENABLE; |
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ret = sch56xx_write_virtual_reg(data->addr, |
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SCH56XX_REG_WDOG_OUTPUT_ENABLE, val); |
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if (ret) |
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goto leave; |
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data->watchdog_output_enable = val; |
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/* 3. Clear the watchdog event bit if set */ |
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val = inb(data->addr + 9); |
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if (val & 0x01) |
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outb(0x01, data->addr + 9); |
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leave: |
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mutex_unlock(data->io_lock); |
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return ret; |
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} |
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static int watchdog_trigger(struct watchdog_device *wddev) |
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{ |
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struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev); |
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int ret; |
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/* Reset the watchdog countdown counter */ |
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mutex_lock(data->io_lock); |
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ret = sch56xx_write_virtual_reg(data->addr, SCH56XX_REG_WDOG_PRESET, |
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data->watchdog_preset); |
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mutex_unlock(data->io_lock); |
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return ret; |
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} |
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static int watchdog_stop(struct watchdog_device *wddev) |
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{ |
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struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev); |
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int ret = 0; |
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u8 val; |
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val = data->watchdog_output_enable & ~SCH56XX_WDOG_OUTPUT_ENABLE; |
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mutex_lock(data->io_lock); |
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ret = sch56xx_write_virtual_reg(data->addr, |
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SCH56XX_REG_WDOG_OUTPUT_ENABLE, val); |
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mutex_unlock(data->io_lock); |
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if (ret) |
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return ret; |
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data->watchdog_output_enable = val; |
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return 0; |
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} |
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static const struct watchdog_ops watchdog_ops = { |
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.owner = THIS_MODULE, |
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.start = watchdog_start, |
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.stop = watchdog_stop, |
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.ping = watchdog_trigger, |
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.set_timeout = watchdog_set_timeout, |
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}; |
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struct sch56xx_watchdog_data *sch56xx_watchdog_register(struct device *parent, |
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u16 addr, u32 revision, struct mutex *io_lock, int check_enabled) |
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{ |
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struct sch56xx_watchdog_data *data; |
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int err, control, output_enable; |
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/* Cache the watchdog registers */ |
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mutex_lock(io_lock); |
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control = |
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sch56xx_read_virtual_reg(addr, SCH56XX_REG_WDOG_CONTROL); |
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output_enable = |
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sch56xx_read_virtual_reg(addr, SCH56XX_REG_WDOG_OUTPUT_ENABLE); |
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mutex_unlock(io_lock); |
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if (control < 0) |
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return NULL; |
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if (output_enable < 0) |
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return NULL; |
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if (check_enabled && !(output_enable & SCH56XX_WDOG_OUTPUT_ENABLE)) { |
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pr_warn("Watchdog not enabled by BIOS, not registering\n"); |
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return NULL; |
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} |
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data = kzalloc(sizeof(struct sch56xx_watchdog_data), GFP_KERNEL); |
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if (!data) |
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return NULL; |
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data->addr = addr; |
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data->io_lock = io_lock; |
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strlcpy(data->wdinfo.identity, "sch56xx watchdog", |
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sizeof(data->wdinfo.identity)); |
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data->wdinfo.firmware_version = revision; |
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data->wdinfo.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT; |
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if (!nowayout) |
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data->wdinfo.options |= WDIOF_MAGICCLOSE; |
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data->wddev.info = &data->wdinfo; |
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data->wddev.ops = &watchdog_ops; |
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data->wddev.parent = parent; |
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data->wddev.timeout = 60; |
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data->wddev.min_timeout = 1; |
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data->wddev.max_timeout = 255 * 60; |
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if (nowayout) |
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set_bit(WDOG_NO_WAY_OUT, &data->wddev.status); |
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if (output_enable & SCH56XX_WDOG_OUTPUT_ENABLE) |
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set_bit(WDOG_ACTIVE, &data->wddev.status); |
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/* Since the watchdog uses a downcounter there is no register to read |
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the BIOS set timeout from (if any was set at all) -> |
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Choose a preset which will give us a 1 minute timeout */ |
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if (control & SCH56XX_WDOG_TIME_BASE_SEC) |
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data->watchdog_preset = 60; /* seconds */ |
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else |
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data->watchdog_preset = 1; /* minute */ |
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data->watchdog_control = control; |
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data->watchdog_output_enable = output_enable; |
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watchdog_set_drvdata(&data->wddev, data); |
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err = watchdog_register_device(&data->wddev); |
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if (err) { |
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pr_err("Registering watchdog chardev: %d\n", err); |
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kfree(data); |
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return NULL; |
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} |
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return data; |
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} |
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EXPORT_SYMBOL(sch56xx_watchdog_register); |
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void sch56xx_watchdog_unregister(struct sch56xx_watchdog_data *data) |
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{ |
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watchdog_unregister_device(&data->wddev); |
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kfree(data); |
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} |
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EXPORT_SYMBOL(sch56xx_watchdog_unregister); |
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/* |
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* platform dev find, add and remove functions |
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*/ |
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static int __init sch56xx_find(int sioaddr, const char **name) |
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{ |
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u8 devid; |
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unsigned short address; |
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int err; |
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err = superio_enter(sioaddr); |
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if (err) |
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return err; |
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devid = superio_inb(sioaddr, SIO_REG_DEVID); |
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switch (devid) { |
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case SIO_SCH5627_ID: |
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*name = "sch5627"; |
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break; |
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case SIO_SCH5636_ID: |
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*name = "sch5636"; |
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break; |
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default: |
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pr_debug("Unsupported device id: 0x%02x\n", |
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(unsigned int)devid); |
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err = -ENODEV; |
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goto exit; |
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} |
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superio_select(sioaddr, SIO_SCH56XX_LD_EM); |
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if (!(superio_inb(sioaddr, SIO_REG_ENABLE) & 0x01)) { |
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pr_warn("Device not activated\n"); |
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err = -ENODEV; |
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goto exit; |
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} |
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/* |
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* Warning the order of the low / high byte is the other way around |
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* as on most other superio devices!! |
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*/ |
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address = superio_inb(sioaddr, SIO_REG_ADDR) | |
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superio_inb(sioaddr, SIO_REG_ADDR + 1) << 8; |
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if (address == 0) { |
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pr_warn("Base address not set\n"); |
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err = -ENODEV; |
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goto exit; |
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} |
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err = address; |
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exit: |
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superio_exit(sioaddr); |
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return err; |
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} |
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static int __init sch56xx_device_add(int address, const char *name) |
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{ |
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struct resource res = { |
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.start = address, |
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.end = address + REGION_LENGTH - 1, |
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.flags = IORESOURCE_IO, |
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}; |
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int err; |
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sch56xx_pdev = platform_device_alloc(name, address); |
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if (!sch56xx_pdev) |
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return -ENOMEM; |
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res.name = sch56xx_pdev->name; |
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err = acpi_check_resource_conflict(&res); |
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if (err) |
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goto exit_device_put; |
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err = platform_device_add_resources(sch56xx_pdev, &res, 1); |
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if (err) { |
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pr_err("Device resource addition failed\n"); |
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goto exit_device_put; |
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} |
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err = platform_device_add(sch56xx_pdev); |
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if (err) { |
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pr_err("Device addition failed\n"); |
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goto exit_device_put; |
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} |
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return 0; |
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exit_device_put: |
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platform_device_put(sch56xx_pdev); |
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return err; |
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} |
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static int __init sch56xx_init(void) |
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{ |
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int address; |
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const char *name = NULL; |
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address = sch56xx_find(0x4e, &name); |
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if (address < 0) |
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address = sch56xx_find(0x2e, &name); |
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if (address < 0) |
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return address; |
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return sch56xx_device_add(address, name); |
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} |
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static void __exit sch56xx_exit(void) |
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{ |
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platform_device_unregister(sch56xx_pdev); |
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} |
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MODULE_DESCRIPTION("SMSC SCH56xx Hardware Monitoring Common Code"); |
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MODULE_AUTHOR("Hans de Goede <[email protected]>"); |
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MODULE_LICENSE("GPL"); |
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module_init(sch56xx_init); |
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module_exit(sch56xx_exit);
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