drm/amdgpu/pm: add smu i2c implementation for navi1x (v5)

And handle more than just EEPROMs.

v2: fix restart handling between transactions.
v3: handle 7 to 8 bit addr conversion
v4: Fix &req --> req. (Luben T)
v5: squash in i2c channel fix
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>

drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c

@@ -2735,6 +2735,120 @@ static ssize_t navi10_get_legacy_gpu_metrics(struct smu_context *smu,
 	return sizeof(struct gpu_metrics_v1_3);
 }
 
+static int navi10_i2c_xfer(struct i2c_adapter *i2c_adap,
+			   struct i2c_msg *msgs, int num)
+{
+	struct amdgpu_device *adev = to_amdgpu_device(i2c_adap);
+	struct smu_table_context *smu_table = &adev->smu.smu_table;
+	struct smu_table *table = &smu_table->driver_table;
+	SwI2cRequest_t *req, *res = (SwI2cRequest_t *)table->cpu_addr;
+	u16 bytes_to_transfer, remaining_bytes, msg_bytes;
+	u16 available_bytes = MAX_SW_I2C_COMMANDS;
+	int i, j, r, c;
+	u8 slave;
+
+	/* only support a single slave addr per transaction */
+	slave = msgs[0].addr;
+	for (i = 0; i < num; i++) {
+		if (slave != msgs[i].addr)
+			return -EINVAL;
+		bytes_to_transfer += min(msgs[i].len, available_bytes);
+		available_bytes -= bytes_to_transfer;
+	}
+
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req)
+		return -ENOMEM;
+
+	req->I2CcontrollerPort = 0;
+	req->I2CSpeed = I2C_SPEED_FAST_400K;
+	req->SlaveAddress = slave << 1; /* 8 bit addresses */
+	req->NumCmds = bytes_to_transfer;
+
+	remaining_bytes = bytes_to_transfer;
+	c = 0;
+	for (i = 0; i < num; i++) {
+		struct i2c_msg *msg = &msgs[i];
+
+		msg_bytes = min(msg->len, remaining_bytes);
+		for (j = 0; j < msg_bytes; j++) {
+			SwI2cCmd_t *cmd = &req->SwI2cCmds[c++];
+
+			remaining_bytes--;
+			if (!(msg[i].flags & I2C_M_RD)) {
+				/* write */
+				cmd->CmdConfig |= I2C_CMD_WRITE;
+				cmd->RegisterAddr = msg->buf[j];
+			}
+			if ((msg[i].flags & I2C_M_STOP) ||
+			    (!remaining_bytes))
+				cmd->CmdConfig |= CMDCONFIG_STOP_MASK;
+			if ((i > 0) && !(msg[i].flags & I2C_M_NOSTART))
+				cmd->CmdConfig |= CMDCONFIG_RESTART_BIT;
+		}
+	}
+	mutex_lock(&adev->smu.mutex);
+	r = smu_cmn_update_table(&adev->smu, SMU_TABLE_I2C_COMMANDS, 0, req, true);
+	mutex_unlock(&adev->smu.mutex);
+	if (r)
+		goto fail;
+
+	remaining_bytes = bytes_to_transfer;
+	c = 0;
+	for (i = 0; i < num; i++) {
+		struct i2c_msg *msg = &msgs[i];
+
+		msg_bytes = min(msg->len, remaining_bytes);
+		for (j = 0; j < msg_bytes; j++) {
+			SwI2cCmd_t *cmd = &res->SwI2cCmds[c++];
+
+			remaining_bytes--;
+			if (msg[i].flags & I2C_M_RD)
+				msg->buf[j] = cmd->Data;
+		}
+	}
+	r = bytes_to_transfer;
+
+fail:
+	kfree(req);
+
+	return r;
+}
+
+static u32 navi10_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+
+static const struct i2c_algorithm navi10_i2c_algo = {
+	.master_xfer = navi10_i2c_xfer,
+	.functionality = navi10_i2c_func,
+};
+
+static int navi10_i2c_control_init(struct smu_context *smu, struct i2c_adapter *control)
+{
+	struct amdgpu_device *adev = to_amdgpu_device(control);
+	int res;
+
+	control->owner = THIS_MODULE;
+	control->class = I2C_CLASS_SPD;
+	control->dev.parent = &adev->pdev->dev;
+	control->algo = &navi10_i2c_algo;
+	snprintf(control->name, sizeof(control->name), "AMDGPU SMU");
+
+	res = i2c_add_adapter(control);
+	if (res)
+		DRM_ERROR("Failed to register hw i2c, err: %d\n", res);
+
+	return res;
+}
+
+static void navi10_i2c_control_fini(struct smu_context *smu, struct i2c_adapter *control)
+{
+	i2c_del_adapter(control);
+}
+
 static ssize_t navi10_get_gpu_metrics(struct smu_context *smu,
 				      void **table)
 {
@@ -3078,6 +3192,8 @@ static const struct pptable_funcs navi10_ppt_funcs = {
 	.set_default_dpm_table = navi10_set_default_dpm_table,
 	.dpm_set_vcn_enable = navi10_dpm_set_vcn_enable,
 	.dpm_set_jpeg_enable = navi10_dpm_set_jpeg_enable,
+	.i2c_init = navi10_i2c_control_init,
+	.i2c_fini = navi10_i2c_control_fini,
 	.print_clk_levels = navi10_print_clk_levels,
 	.force_clk_levels = navi10_force_clk_levels,
 	.populate_umd_state_clk = navi10_populate_umd_state_clk,