Re: [PATCH 15/21] usb: chipidea: msm: Mux over secondary phy at the right time

Bjorn Andersson
2016-06-28T04:51:49Z

On Sun 26 Jun 00:28 PDT 2016, Stephen Boyd wrote:

> We need to pick the correct phy at runtime based on how the SoC
> has been wired onto the board. If the secondary phy is used, take
> it out of reset and mux over to it by writing into the TCSR
> register. Make sure to do this on reset too, because this
> register is reset to the default value (primary phy) after the
> RESET bit is set in USBCMD.
>
> Cc: Peter Chen <peter.chen@nxp.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
> ---
> drivers/usb/chipidea/ci_hdrc_msm.c | 78 +++++++++++++++++++++++++++++++++++---
> 1 file changed, 73 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/usb/chipidea/ci_hdrc_msm.c b/drivers/usb/chipidea/ci_hdrc_msm.c
[..]
>
> +static int ci_hdrc_msm_mux_phy(struct ci_hdrc_msm *ci,
> + struct platform_device *pdev)
> +{
> + struct regmap *regmap;
> + struct device_node *syscon;
> + struct device *dev = &pdev->dev;
> + u32 off, val;
> + int ret;
> +
> + syscon = of_parse_phandle(dev->of_node, "phy-select", 0);
> + if (!syscon)
> + return 0;
> +
> + regmap = syscon_node_to_regmap(syscon);
> + if (IS_ERR(regmap))
> + return PTR_ERR(regmap);
> +
> + ret = of_property_read_u32_index(dev->of_node, "phy-select", 1, &off);
> + if (ret < 0) {
> + dev_err(dev, "no offset in syscon\n");
> + return -EINVAL;
> + }
> +
> + ret = of_property_read_u32_index(dev->of_node, "phy-select", 2, &val);
> + if (ret < 0) {
> + dev_err(dev, "no value in syscon\n");
> + return -EINVAL;
> + }
> +
> + ret = regmap_write(regmap, off, val);

I recently found out (thanks to a comment from Srinivas) that you can
drop the last two error checks by using
of_parse_phandle_with_fixed_args() as in:

struct of_phandle_args args;

ret = of_parse_phandle_with_fixed_args(dev->of_node, "phy-select", 2, 0, &args);
if (ret < 0)
...

regmap = syscon_node_to_regmap(args.np);
of_node_put(args.np);
if (IS_ERR(regmap))
...

ret = regmap_write(regmap, args.args[0], args.args[1]);

> + if (ret)
> + return ret;
> +
> + ci->secondary_phy = !!val;
> + if (ci->secondary_phy) {
> + val = readl_relaxed(ci->base + HS_PHY_SEC_CTRL);
> + val |= HS_PHY_DIG_CLAMP_N;
> + writel_relaxed(val, ci->base + HS_PHY_SEC_CTRL);
> + }
> +
> + return 0;
> +}
> +
> static int ci_hdrc_msm_probe(struct platform_device *pdev)
> {
> struct ci_hdrc_msm *ci;
> struct platform_device *plat_ci;
> struct clk *clk;
> struct reset_control *reset;
> + struct resource *res;
> + void __iomem *base;

Doesn't look like you need "base".

> + resource_size_t size;
> int ret;
>
> dev_dbg(&pdev->dev, "ci_hdrc_msm_probe\n");
> @@ -76,6 +132,15 @@ static int ci_hdrc_msm_probe(struct platform_device *pdev)
> if (IS_ERR(clk))
> return PTR_ERR(clk);
>
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res)
> + return -ENODEV;
> +
> + size = resource_size(res);
> + ci->base = base = devm_ioremap(&pdev->dev, res->start, size);
> + if (!base)
> + return -ENOMEM;

Replace these two snippets with:

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
ci->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(ci->base))
return PTR_ERR(ci->base);

> +
> reset_control_assert(reset);
> usleep_range(10000, 12000);
> reset_control_deassert(reset);

Regards,
Bjorn