On Tue, 8 Jan 2019 at 08:11, Jae Hyun Yoo [off-list ref] wrote:

+       ret = of_property_read_u32(priv->dev->of_node, "cmd-timeout-ms",
+                                  &priv->cmd_timeout_ms);
+       if (ret || priv->cmd_timeout_ms > PECI_CMD_TIMEOUT_MS_MAX ||
+           priv->cmd_timeout_ms == 0) {
+               if (!ret)
+                       dev_warn(priv->dev,
+                                "Invalid cmd-timeout-ms : %u. Use default : %u\n",
+                                priv->cmd_timeout_ms,
+                                PECI_CMD_TIMEOUT_MS_DEFAULT);

As this property is documented as optional, I'd split out the checks
so you only warn when the value provided is invalid.

+
+       regmap_write(priv->regmap, ASPEED_PECI_CTRL,
+                    FIELD_PREP(PECI_CTRL_CLK_DIV_MASK, PECI_CLK_DIV_DEFAULT) |
+                    PECI_CTRL_PECI_CLK_EN);
+
+       /**

Just the one *.

+        * Timing negotiation period setting.
+        * The unit of the programmed value is 4 times of PECI clock period.
+        */
+       regmap_write(priv->regmap, ASPEED_PECI_TIMING,
+                    FIELD_PREP(PECI_TIMING_MESSAGE_MASK, msg_timing) |
+                    FIELD_PREP(PECI_TIMING_ADDRESS_MASK, addr_timing));

+static int aspeed_peci_xfer(struct peci_adapter *adapter,
+                           struct peci_xfer_msg *msg)
+{
+       struct aspeed_peci *priv = peci_get_adapdata(adapter);
+
+       return aspeed_peci_xfer_native(priv, msg);
+}

It looks like you could do the peci_get_adapdata in
aspeed_peci_xfer_native and drop the need for this wrapper.

+
+static int aspeed_peci_probe(struct platform_device *pdev)
+{

+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       base = devm_ioremap_resource(&pdev->dev, res);
+       if (IS_ERR(base)) {
+               ret = PTR_ERR(base);
+               goto err_put_adapter_dev;
+       }
+
+       priv->regmap = devm_regmap_init_mmio(&pdev->dev, base,
+                                            &aspeed_peci_regmap_config);
+       if (IS_ERR(priv->regmap)) {
+               ret = PTR_ERR(priv->regmap);
+               goto err_put_adapter_dev;
+       }
+
+       /**
+        * We check that the regmap works on this very first access,
+        * but as this is an MMIO-backed regmap, subsequent regmap
+        * access is not going to fail and we skip error checks from
+        * this point.

Why do you use a regmap for this driver? AFAICT it has exclusive
ownership over the register range it uses, which is sometimes a reason
to use a regmap over a mmio region.

I'm not sure if you've ever disassembled drivers/base/regmap/regmap.o,
but if you do you will find that a single mmio read turns into
hundreds of instructions.

Cheers,

Joel