Messages in this thread | | | Subject | Re: [PATCH v10 06/12] peci: Add a PECI adapter driver for Aspeed AST24xx/AST25xx | From | Jae Hyun Yoo <> | Date | Mon, 14 Jan 2019 14:49:48 -0800 |
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On 1/14/2019 3:37 AM, Joel Stanley wrote: > On Tue, 8 Jan 2019 at 08:11, Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> 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. >
Please check the above 'if' statement too. It prints out warning only when the property is defined in device tree but the value is out of range.
>> + >> + 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 *. >
Will fix it.
>> + * 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. >
Yes, that would be neater. Will remove 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. >
No specific reason. regmap makes some overhead as you mentioned but it also provides some advantages on access simplification, endianness handling and register dump at run time. I would not insist using of regmap if you prefer using of raw readl and writel. Do you want replace regmap with readl and writel in this driver?
Thanks, Jae
> Cheers, > > Joel >
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