[PATCH v2 4/8] i2c: piix4: Move SMBus port selection into function

From: Terry Bowman
Date: Tue Jan 18 2022 - 17:12:54 EST


Move port selection code into a separate function. Refactor is in
preparation for following MMIO changes.

Signed-off-by: Terry Bowman <terry.bowman@xxxxxxx>
To: Guenter Roeck <linux@xxxxxxxxxxxx>
To: linux-watchdog@xxxxxxxxxxxxxxx
To: Jean Delvare <jdelvare@xxxxxxxx>
To: linux-i2c@xxxxxxxxxxxxxxx
To: Wolfram Sang <wsa@xxxxxxxxxx>
To: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
To: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: Wim Van Sebroeck <wim@xxxxxxxxxxxxxxxxxx>
Cc: Robert Richter <rrichter@xxxxxxx>
Cc: Thomas Lendacky <thomas.lendacky@xxxxxxx>
---
drivers/i2c/busses/i2c-piix4.c | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index 35fcb61f4750..58b613b78c97 100644
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -700,6 +700,19 @@ static void piix4_imc_wakeup(void)
release_region(KERNCZ_IMC_IDX, 2);
}

+static int piix4_sb800_port_sel(u8 port)
+{
+ u8 smba_en_lo;
+
+ outb_p(piix4_port_sel_sb800, SB800_PIIX4_SMB_IDX);
+ smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1);
+
+ if ((smba_en_lo & piix4_port_mask_sb800) != port)
+ outb_p((smba_en_lo & ~piix4_port_mask_sb800) | port,
+ SB800_PIIX4_SMB_IDX + 1);
+
+ return (smba_en_lo & piix4_port_mask_sb800);
+}
/*
* Handles access to multiple SMBus ports on the SB800.
* The port is selected by bits 2:1 of the smb_en register (0x2c).
@@ -716,8 +729,7 @@ static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr,
unsigned short piix4_smba = adapdata->smba;
int retries = MAX_TIMEOUT;
int smbslvcnt;
- u8 smba_en_lo;
- u8 port;
+ u8 prev_port;
int retval;

retval = piix4_sb800_region_setup(&adap->dev);
@@ -777,18 +789,12 @@ static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr,
}
}

- outb_p(piix4_port_sel_sb800, SB800_PIIX4_SMB_IDX);
- smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1);
-
- port = adapdata->port;
- if ((smba_en_lo & piix4_port_mask_sb800) != port)
- outb_p((smba_en_lo & ~piix4_port_mask_sb800) | port,
- SB800_PIIX4_SMB_IDX + 1);
+ prev_port = piix4_sb800_port_sel(adapdata->port);

retval = piix4_access(adap, addr, flags, read_write,
command, size, data);

- outb_p(smba_en_lo, SB800_PIIX4_SMB_IDX + 1);
+ piix4_sb800_port_sel(prev_port);

/* Release the semaphore */
outb_p(smbslvcnt | 0x20, SMBSLVCNT);
--
2.30.2