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hwmon: (w83627ehf) Optimize multi-bank register access

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Assume that each register is banked, and set the bank for each access.
Cache the bank number so it only needs to be set if it changes.

Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Acked-by: Ian Dobson <i.dobson@planet-ian.com>
This commit is contained in:
Guenter Roeck 2011-02-06 08:10:15 -08:00
parent e7e1ca6ef4
commit 83cc8985b8
1 changed files with 11 additions and 15 deletions
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26
drivers/hwmon/w83627ehf.c
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@ -304,6 +304,7 @@ struct w83627ehf_data {
unsigned long last_updated; /* In jiffies */
/* Register values */
u8 bank; /* current register bank */
u8 in_num; /* number of in inputs we have */
u8 in[10]; /* Register value */
u8 in_max[10]; /* Register value */
@ -347,21 +348,19 @@ struct w83627ehf_sio_data {
enum kinds kind;
};
/* Registers 0x50-0x5f are banked */
/*
* On older chips, only registers 0x50-0x5f are banked.
* On more recent chips, all registers are banked.
* Assume that is the case and set the bank number for each access.
* Cache the bank number so it only needs to be set if it changes.
*/
static inline void w83627ehf_set_bank(struct w83627ehf_data *data, u16 reg)
{
if ((reg & 0x00f0) == 0x50) {
u8 bank = reg >> 8;
if (data->bank != bank) {
outb_p(W83627EHF_REG_BANK, data->addr + ADDR_REG_OFFSET);
outb_p(reg >> 8, data->addr + DATA_REG_OFFSET);
}
}
/* Not strictly necessary, but play it safe for now */
static inline void w83627ehf_reset_bank(struct w83627ehf_data *data, u16 reg)
{
if (reg & 0xff00) {
outb_p(W83627EHF_REG_BANK, data->addr + ADDR_REG_OFFSET);
outb_p(0, data->addr + DATA_REG_OFFSET);
outb_p(bank, data->addr + DATA_REG_OFFSET);
data->bank = bank;
}
}
@ -379,10 +378,8 @@ static u16 w83627ehf_read_value(struct w83627ehf_data *data, u16 reg)
data->addr + ADDR_REG_OFFSET);
res = (res << 8) + inb_p(data->addr + DATA_REG_OFFSET);
}
w83627ehf_reset_bank(data, reg);
mutex_unlock(&data->lock);
return res;
}
@ -401,7 +398,6 @@ static int w83627ehf_write_value(struct w83627ehf_data *data, u16 reg,
data->addr + ADDR_REG_OFFSET);
}
outb_p(value & 0xff, data->addr + DATA_REG_OFFSET);
w83627ehf_reset_bank(data, reg);
mutex_unlock(&data->lock);
return 0;