On Fri, Jan 29, 2016 at 10:44:52AM +0100, Jean Delvare wrote:
> The SB800 register reference guide says that the SMBus port selection
> bits may not always be in register Smbus0En (0x2c) but could
> alternatively be found in register Smbus0Sel (0x2e) depending on the
> settings in register Smbus0SelEn (0x2f.) Add support for this
> configuration.
>
> Signed-off-by: Jean Delvare <jdelvare@xxxxxxx>
> Cc: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
One small comment, see below.
Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> Cc: Christian Fetzer <fetzer.ch@xxxxxxxxx>
> Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-piix4.c | 30 ++++++++++++++++++++++++++----
> 1 file changed, 26 insertions(+), 4 deletions(-)
>
> --- linux-4.5-rc0.orig/drivers/i2c/busses/i2c-piix4.c 2016-01-26 18:25:38.487310421 +0100
> +++ linux-4.5-rc0/drivers/i2c/busses/i2c-piix4.c 2016-01-29 07:54:35.135765313 +0100
> @@ -85,8 +85,13 @@
> /* SB800 constants */
> #define SB800_PIIX4_SMB_IDX 0xcd6
>
> -/* SB800 port is selected by bits 2:1 of the smb_en register (0x2c) */
> +/*
> + * SB800 port is selected by bits 2:1 of the smb_en register (0x2c)
> + * or the smb_sel register (0x2e), depending on bit 0 of register 0x2f.
> + */
> #define SB800_PIIX4_PORT_IDX 0x2c
> +#define SB800_PIIX4_PORT_IDX_ALT 0x2e
> +#define SB800_PIIX4_PORT_IDX_SEL 0x2f
> #define SB800_PIIX4_PORT_IDX_MASK 0x06
>
> /* insmod parameters */
> @@ -136,8 +141,13 @@ static const struct dmi_system_id piix4_
> { },
> };
>
> -/* SB800 globals */
> +/*
> + * SB800 globals
> + * piix4_mutex_sb800 protects piix4_port_sel_sb800 and the pair
> + * of I/O ports at SB800_PIIX4_SMB_IDX.
> + */
> static DEFINE_MUTEX(piix4_mutex_sb800);
> +static u8 piix4_port_sel_sb800;
> static const char *piix4_main_port_names_sb800[PIIX4_MAX_ADAPTERS] = {
> " port 0", " port 2", " port 3", " port 4"
> };
> @@ -254,7 +264,7 @@ static int piix4_setup_sb800(struct pci_
> const struct pci_device_id *id, u8 aux)
> {
> unsigned short piix4_smba;
> - u8 smba_en_lo, smba_en_hi, smb_en, smb_en_status;
> + u8 smba_en_lo, smba_en_hi, smb_en, smb_en_status, port_sel;
> u8 i2ccfg, i2ccfg_offset = 0x10;
>
> /* SB800 and later SMBus does not support forcing address */
> @@ -334,6 +344,18 @@ static int piix4_setup_sb800(struct pci_
> "SMBus Host Controller at 0x%x, revision %d\n",
> piix4_smba, i2ccfg >> 4);
>
> + /* Find which register is used for port selection */
> + mutex_lock(&piix4_mutex_sb800);
> + outb_p(SB800_PIIX4_PORT_IDX_SEL, SB800_PIIX4_SMB_IDX);
> + port_sel = inb_p(SB800_PIIX4_SMB_IDX + 1);
> + piix4_port_sel_sb800 = (port_sel & 0x01) ? SB800_PIIX4_PORT_IDX_ALT
> + : SB800_PIIX4_PORT_IDX;
> + mutex_unlock(&piix4_mutex_sb800);
> +
> + dev_info(&PIIX4_dev->dev,
> + "Using register 0x%02x for SMBus port selection\n",
> + (unsigned int)piix4_port_sel_sb800);
Would dev_dbg() be better here? Not sure how useful this information is
for normal users.
> +
> return piix4_smba;
> }
>
> @@ -563,7 +585,7 @@ static s32 piix4_access_sb800(struct i2c
>
> mutex_lock(&piix4_mutex_sb800);
>
> - outb_p(SB800_PIIX4_PORT_IDX, SB800_PIIX4_SMB_IDX);
> + outb_p(piix4_port_sel_sb800, SB800_PIIX4_SMB_IDX);
> smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1);
>
> port = adapdata->port;
>
> --
> Jean Delvare
> SUSE L3 Support
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