Implement the i2c_algorithm operations to enable support for AMD ASF
(Alert Standard Format) with SMBus. This enhancement includes:
- Adding functionality to identify and select the supported ASF functions.
- Implementing mechanisms for registering and deregistering I2C slave
devices.
- Providing support for data transfer operations over ASF.
These changes will extend the piix4 driver to accommodate the additional
capabilities provided by AMD's ASF Controller.
Additionally, include a 'select' Kconfig entry for CONFIG_I2C_PIIX4, as
the current patch utilizes reg_slave and unreg_slave callbacks, which are
controlled by IS_ENABLED(CONFIG_I2C_SLAVE).
Co-developed-by: Sanket Goswami <Sanket.Goswami@xxxxxxx>
Signed-off-by: Sanket Goswami <Sanket.Goswami@xxxxxxx>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@xxxxxxx>
---
drivers/i2c/busses/Kconfig | 1 +
drivers/i2c/busses/i2c-piix4.c | 184 +++++++++++++++++++++++++++++++++
2 files changed, 185 insertions(+)
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index a22f9125322a..10ad839bf4a2 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -197,6 +197,7 @@ config I2C_PIIX4
tristate "Intel PIIX4 and compatible (ATI/AMD/Serverworks/Broadcom/SMSC)"
depends on PCI && HAS_IOPORT
select I2C_SMBUS
+ select I2C_SLAVE
help
If you say yes to this option, support will be included for the Intel
PIIX4 family of mainboard I2C interfaces. Specifically, the following
diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index d56083e58a2d..003cb04312cf 100644
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -50,6 +50,22 @@
#define SMBSLVEVT (0xA + piix4_smba)
#define SMBSLVDAT (0xC + piix4_smba)
+/* SB800 ASF register bits */
+#define SB800_ASF_SLV_LISTN 0
+#define SB800_ASF_SLV_INTR 1
+#define SB800_ASF_SLV_RST 4
+#define SB800_ASF_PEC_SP 5
+#define SB800_ASF_DATA_EN 7
+#define SB800_ASF_MSTR_EN 16
+#define SB800_ASF_CLK_EN 17
+
+/* SB800 ASF address offsets */
+#define ASFLISADDR (9 + piix4_smba)
+#define ASFSTA (0xA + piix4_smba)
+#define ASFSLVSTA (0xD + piix4_smba)
+#define ASFDATABNKSEL (0x13 + piix4_smba)
+#define ASFSLVEN (0x15 + piix4_smba)
+
/* count for request_region */
#define SMBIOSIZE 9
@@ -101,6 +117,7 @@
#define SB800_PIIX4_FCH_PM_ADDR 0xFED80300
#define SB800_PIIX4_FCH_PM_SIZE 8
+#define SB800_ASF_BLOCK_MAX_BYTES 72
/* insmod parameters */
@@ -168,6 +185,7 @@ struct sb800_mmio_cfg {
enum piix4_algo {
PIIX4_SB800,
PIIX4_SMBUS,
+ SMBUS_ASF,
};
struct i2c_piix4_adapdata {
@@ -179,6 +197,7 @@ struct i2c_piix4_adapdata {
u8 port; /* Port number, shifted */
struct sb800_mmio_cfg mmio_cfg;
u8 algo_select;
+ struct i2c_client *slave;
};
static int piix4_sb800_region_request(struct device *dev,
@@ -887,6 +906,168 @@ static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr,
return retval;
}
+static void sb800_asf_update_bits(unsigned short piix4_smba, u8 bit, unsigned long offset, bool set)
+{
+ unsigned long reg;
+
+ reg = inb_p(offset);
+ if (set)
+ set_bit(bit, ®);
+ else
+ clear_bit(bit, ®);
+ outb_p(reg, offset);
+}
+
+static void sb800_asf_update_bytes(struct i2c_piix4_adapdata *adap, u8 bit, bool set)
+{
+ unsigned long reg;
+
+ reg = ioread32(adap->mmio_cfg.addr);
+ if (set)
+ set_bit(bit, ®);
+ else
+ clear_bit(bit, ®);
+ iowrite32(reg, adap->mmio_cfg.addr);
+}
+
+static void sb800_asf_setup_slave(struct i2c_piix4_adapdata *adap)
+{
+ unsigned short piix4_smba = adap->smba;
+
+ /* Reset both host and slave before setting up */
+ outb_p(0, SMBHSTSTS);
+ outb_p(0, ASFSLVSTA);
+ outb_p(0, ASFSTA);
+
+ /* Update slave address */
+ sb800_asf_update_bits(piix4_smba, SB800_ASF_SLV_LISTN, ASFLISADDR, true);
+ /* Enable slave and set the clock */
+ sb800_asf_update_bytes(adap, SB800_ASF_MSTR_EN, false);
+ sb800_asf_update_bytes(adap, SB800_ASF_CLK_EN, true);
+ /* Enable slave interrupt */
+ sb800_asf_update_bits(piix4_smba, SB800_ASF_SLV_INTR, ASFSLVEN, true);
+ sb800_asf_update_bits(piix4_smba, SB800_ASF_SLV_RST, ASFSLVEN, false);
+ /* Enable PEC and PEC append */
+ sb800_asf_update_bits(piix4_smba, SB800_ASF_DATA_EN, SMBHSTCNT, true);
+ sb800_asf_update_bits(piix4_smba, SB800_ASF_PEC_SP, SMBHSTCNT, true);
+}
+
+static s32 sb800_asf_access(struct i2c_adapter *adap, u16 addr, u8 command, u8 *data)
+{
+ struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);
+ unsigned short piix4_smba = adapdata->smba;
+ u8 len;
+ int i;
+
+ outb_p((addr << 1), SMBHSTADD);
+ outb_p(command, SMBHSTCMD);
+ len = data[0];
+ if (len == 0 || len > SB800_ASF_BLOCK_MAX_BYTES)
+ return -EINVAL;
+
+ outb_p(len, SMBHSTDAT0);
+ inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */
+ for (i = 1; i <= len; i++)
+ outb_p(data[i], SMBBLKDAT);
+
+ outb_p(PIIX4_BLOCK_DATA, SMBHSTCNT);
+ /* Enable PEC and PEC append */
+ sb800_asf_update_bits(piix4_smba, SB800_ASF_DATA_EN, SMBHSTCNT, true);
+ sb800_asf_update_bits(piix4_smba, SB800_ASF_PEC_SP, SMBHSTCNT, true);
+
+ return piix4_transaction(adap);
+}
+
+static int sb800_asf_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);
+ unsigned short piix4_smba = adapdata->smba;
+ u8 asf_data[SB800_ASF_BLOCK_MAX_BYTES];
+ struct i2c_msg *dev_msgs = msgs;
+ u8 prev_port;
+ int ret;
+
+ if (msgs->flags & I2C_M_RD) {
+ dev_err(&adap->dev, "Read not supported\n");
+ return -EOPNOTSUPP;
+ }
+
+ /* Exclude the receive header and PEC */
+ if (msgs->len > SB800_ASF_BLOCK_MAX_BYTES - 3) {
+ dev_err(&adap->dev, "ASF max message length exceeded\n");
+ return -EOPNOTSUPP;
+ }
+
+ asf_data[0] = dev_msgs->len;
+ memcpy(asf_data + 1, dev_msgs[0].buf, dev_msgs->len);
+
+ ret = piix4_sb800_region_request(&adap->dev, &adapdata->mmio_cfg);
+ if (ret)
+ return ret;
+
+ sb800_asf_update_bits(piix4_smba, SB800_ASF_SLV_RST, ASFSLVEN, true);
+ sb800_asf_update_bits(piix4_smba, SB800_ASF_SLV_LISTN, ASFLISADDR, false);
+ /* Clear ASF slave status */
+ outb_p(0, ASFSLVSTA);
+
+ /* Enable ASF SMBus master function */
+ sb800_asf_update_bytes(adapdata, SB800_ASF_MSTR_EN, true);
+ prev_port = piix4_sb800_port_sel(adapdata->port, &adapdata->mmio_cfg);
+ ret = sb800_asf_access(adap, msgs->addr, msgs[0].buf[0], asf_data);
+ piix4_sb800_port_sel(prev_port, &adapdata->mmio_cfg);
+ sb800_asf_setup_slave(adapdata);
+ piix4_sb800_region_release(&adap->dev, &adapdata->mmio_cfg);
+ return ret;
+}
+
+static int sb800_asf_reg_slave(struct i2c_client *slave)
+{
+ struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(slave->adapter);
+ unsigned short piix4_smba = adapdata->smba;
+ int ret;
+ u8 reg;
+
+ if (adapdata->slave)
+ return -EBUSY;
+
+ ret = piix4_sb800_region_request(&slave->dev, &adapdata->mmio_cfg);
+ if (ret)
+ return ret;
+
+ reg = (slave->addr << 1) | BIT(0);
+ outb_p(reg, ASFLISADDR);
+
+ sb800_asf_setup_slave(adapdata);
+ adapdata->slave = slave;
+ sb800_asf_update_bits(piix4_smba, SB800_ASF_DATA_EN, ASFDATABNKSEL, false);
+ piix4_sb800_region_release(&slave->dev, &adapdata->mmio_cfg);
+ return 0;
+}
+
+static int sb800_asf_unreg_slave(struct i2c_client *slave)
+{
+ struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(slave->adapter);
+ unsigned short piix4_smba = adapdata->smba;
+
+ sb800_asf_update_bits(piix4_smba, SB800_ASF_SLV_INTR, ASFSLVEN, false);
+ sb800_asf_update_bits(piix4_smba, SB800_ASF_SLV_RST, ASFSLVEN, true);
+ adapdata->slave = NULL;
+ return 0;
+}
+
+static u32 sb800_asf_func(struct i2c_adapter *adapter)
+{
+ return I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BYTE |
+ I2C_FUNC_SLAVE | I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | I2C_FUNC_SMBUS_PEC;
+}
+
+static const struct i2c_algorithm sb800_asf_smbus_algorithm = {
+ .master_xfer = sb800_asf_xfer,
+ .reg_slave = sb800_asf_reg_slave,
+ .unreg_slave = sb800_asf_unreg_slave,
+ .functionality = sb800_asf_func,
+};
+
static u32 piix4_func(struct i2c_adapter *adapter)
{
return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
@@ -959,6 +1140,9 @@ static int piix4_add_adapter(struct pci_dev *dev, unsigned short smba,
case PIIX4_SB800:
adap->algo = &piix4_smbus_algorithm_sb800;
break;
+ case SMBUS_ASF:
+ adap->algo = &sb800_asf_smbus_algorithm;
+ break;
default:
dev_err(&dev->dev, "Unsupported SMBus algorithm\n");
return -EINVAL;
--
2.25.1
