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SubjectRe: [PATCH v4] usb: phy: samsung: Add support to set pmu isolation
On 12/26/2012 01:28 PM, Vivek Gautam wrote:
> Adding support to parse device node data in order to get
> required properties to set pmu isolation for usb-phy.
>
> Signed-off-by: Vivek Gautam<gautam.vivek@samsung.com>
> ---
> .../devicetree/bindings/usb/samsung-usbphy.txt | 31 ++++
> drivers/usb/phy/samsung-usbphy.c | 145 +++++++++++++++++---
> 2 files changed, 155 insertions(+), 21 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/usb/samsung-usbphy.txt b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
> index 7b26e2d..6b873fd 100644
> --- a/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
> +++ b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
> @@ -9,3 +9,34 @@ Required properties:
> - compatible : should be "samsung,exynos4210-usbphy"
> - reg : base physical address of the phy registers and length of memory mapped
> region.
> +
> +Optional properties:
> +- #address-cells: should be '1' when usbphy node has a child node with 'reg'
> + property.
> +- #size-cells: should be '1' when usbphy node has a child node with 'reg'
> + property.
> +
> +- The child node 'usbphy-pmu' to the node usbphy should provide the following
> + information required by usb-phy controller to enable/disable the phy.
> + - reg : base physical address of PHY control register in PMU which
> + enables/disables the phy controller.
> + The size of this register is the total sum of size of all phy-control
> + registers that the SoC has. For example, the size will be
> + '0x4' in case we have only one phy-control register (like in S3C64XX) or
> + '0x8' in case we have two phy-control registers (like in Exynos4210)
> + and so on.
> +
> +Example:
> + - Exysno4210

s/Exysno/Exynos

> +
> + usbphy@125B0000 {
> + #address-cells =<1>;
> + #size-cells =<1>;
> + compatible = "samsung,exynos4210-usbphy";
> + reg =<0x125B0000 0x100>;
> +
> + usbphy-pmu {
> + /* USB device and host PHY_CONTROL registers */
> + reg =<0x10020704 0x8>;
> + };
> + };
> diff --git a/drivers/usb/phy/samsung-usbphy.c b/drivers/usb/phy/samsung-usbphy.c
> index 5c5e1bb5..b9f4f42 100644
> --- a/drivers/usb/phy/samsung-usbphy.c
> +++ b/drivers/usb/phy/samsung-usbphy.c
> @@ -60,20 +60,42 @@
> #define MHZ (1000*1000)
> #endif
>
> +#define S3C64XX_USBPHY_ENABLE (0x1<< 16)
> +#define EXYNOS_USBPHY_ENABLE (0x1<< 0)
> +
> enum samsung_cpu_type {
> TYPE_S3C64XX,
> TYPE_EXYNOS4210,
> };
>
> /*
> + * struct samsung_usbphy_drvdata - driver data for various SoC variants
> + * @cpu_type: machine identifier
> + * @devphy_en_mask: device phy enable mask for PHY CONTROL register
> + *
> + * Here we have a separate mask for device type phy.
> + * Having different masks for host and device type phy helps
> + * in setting independent masks in case of SoCs like S5PV210,
> + * in which PHY0 and PHY1 enable bits belong to same register
> + * placed at [0] and [1] respectively.

"and are placed at positions 0 and 1 respectively" ?

> + * Although for newer SoCs like exynos these bits belong to
> + * different registers altogether placed at [0].
> + */
> +struct samsung_usbphy_drvdata {
> + int cpu_type;
> + int devphy_en_mask;
> +};
> +
> +/*
> * struct samsung_usbphy - transceiver driver state
> * @phy: transceiver structure
> * @plat: platform data
> * @dev: The parent device supplied to the probe function
> * @clk: usb phy clock
> * @regs: usb phy register memory base
> + * @phyctrl_pmureg: usb device phy-control pmu register memory base

nit: Perhaps we could just call it "pmureg' ?

> * @ref_clk_freq: reference clock frequency selection
> - * @cpu_type: machine identifier
> + * @drv_data: driver data available for different cpu types

Actually it's for different SoCs, not CPUs, right ?

> */
> struct samsung_usbphy {
> struct usb_phy phy;
> @@ -81,12 +103,67 @@ struct samsung_usbphy {
> struct device *dev;
> struct clk *clk;
> void __iomem *regs;
> + void __iomem *phyctrl_pmureg;
> int ref_clk_freq;
> - int cpu_type;
> + const struct samsung_usbphy_drvdata *drv_data;
> };
>
> #define phy_to_sphy(x) container_of((x), struct samsung_usbphy, phy)
>
> +static int samsung_usbphy_parse_dt_param(struct samsung_usbphy *sphy)

nit: s/samsung_usbphy_parse_dt_param/samsung_usbphy_parse_dt ?

> +{
> + struct device_node *usbphy_pmu;
> + u32 reg[2];
> + int ret;
> +
> + if (!sphy->dev->of_node) {
> + dev_err(sphy->dev, "Can't get usb-phy node\n");
> + return -ENODEV;

The function is called only when dev->of_node is not NULL, so this path
is never executed, AFAICS. I would just drop this redundant check.

> + }
> +
> + usbphy_pmu = of_get_child_by_name(sphy->dev->of_node, "usbphy-pmu");
> + if (!usbphy_pmu)
> + dev_warn(sphy->dev, "Can't get usb-phy pmu control node\n");

> + ret = of_property_read_u32_array(usbphy_pmu, "reg", reg,
> + ARRAY_SIZE(reg));
> + if (!ret)
> + sphy->phyctrl_pmureg = ioremap(reg[0], reg[1]);

I don't think this is correct. reg is not really an array of u32 type,
it's an array of address/size tuples. I thought you would use of_iomap()
here. Any reason why you didn't do so ? It would also make it easier to
handle multiple address/size pairs if required.

> +
> + of_node_put(usbphy_pmu);
> +
> + if (IS_ERR_OR_NULL(sphy->phyctrl_pmureg)) {

When is sphy->phyctrl_pmureg assigned a ERR_PTR() value ? Wouldn't it
be enough to simply check for NULL ?

> + dev_err(sphy->dev, "Can't get usb-phy pmu control register\n");
> + return -ENODEV;
> + }
> +
> + return 0;
> +}
> +
> +/*
> + * Set isolation here for phy.
> + * SOCs control this by controlling corresponding PMU registers
> + */
> +static void samsung_usbphy_set_isolation(struct samsung_usbphy *sphy, int on)
> +{
> + u32 reg;
> + int en_mask;
> +
> + if (!sphy->phyctrl_pmureg) {
> + dev_warn(sphy->dev, "Can't set pmu isolation\n");
> + return;
> + }
> +
> + reg = readl(sphy->phyctrl_pmureg);

To make it more generic maybe it's worth to store an offset to the actual
register somewhere, e.g. in the driver_data struct ? This function is
supposed to handle both device and host PHYs, isn't it ?

> + en_mask = sphy->drv_data->devphy_en_mask;
> +
> + if (on)
> + writel(reg& ~en_mask, sphy->phyctrl_pmureg);
> + else
> + writel(reg | en_mask, sphy->phyctrl_pmureg);

nit: This could be also written as:

reg = on ? reg & ~mask : reg | mask;
writel(reg, sphy->phyctrl_pmureg);
> +}
> +
> /*
> * Returns reference clock frequency selection value
> */
> @@ -112,7 +189,7 @@ static int samsung_usbphy_get_refclk_freq(struct samsung_usbphy *sphy)
> refclk_freq = PHYCLK_CLKSEL_48M;
> break;
> default:
> - if (sphy->cpu_type == TYPE_S3C64XX)
> + if (sphy->drv_data->cpu_type == TYPE_S3C64XX)
> refclk_freq = PHYCLK_CLKSEL_48M;
> else
> refclk_freq = PHYCLK_CLKSEL_24M;
> @@ -135,7 +212,7 @@ static void samsung_usbphy_enable(struct samsung_usbphy *sphy)
> phypwr = readl(regs + SAMSUNG_PHYPWR);
> rstcon = readl(regs + SAMSUNG_RSTCON);
>
> - switch (sphy->cpu_type) {
> + switch (sphy->drv_data->cpu_type) {
> case TYPE_S3C64XX:
> phyclk&= ~PHYCLK_COMMON_ON_N;
> phypwr&= ~PHYPWR_NORMAL_MASK;
> @@ -165,7 +242,7 @@ static void samsung_usbphy_disable(struct samsung_usbphy *sphy)
>
> phypwr = readl(regs + SAMSUNG_PHYPWR);
>
> - switch (sphy->cpu_type) {
> + switch (sphy->drv_data->cpu_type) {
> case TYPE_S3C64XX:
> phypwr |= PHYPWR_NORMAL_MASK;
> break;
> @@ -199,6 +276,8 @@ static int samsung_usbphy_init(struct usb_phy *phy)
> /* Disable phy isolation */
> if (sphy->plat&& sphy->plat->pmu_isolation)
> sphy->plat->pmu_isolation(false);
> + else
> + samsung_usbphy_set_isolation(sphy, false);
>
> /* Initialize usb phy registers */
> samsung_usbphy_enable(sphy);
> @@ -228,38 +307,37 @@ static void samsung_usbphy_shutdown(struct usb_phy *phy)
> /* Enable phy isolation */
> if (sphy->plat&& sphy->plat->pmu_isolation)
> sphy->plat->pmu_isolation(true);
> + else
> + samsung_usbphy_set_isolation(sphy, true);
>
> clk_disable_unprepare(sphy->clk);
> }
>
> static const struct of_device_id samsung_usbphy_dt_match[];
>
> -static inline int samsung_usbphy_get_driver_data(struct platform_device *pdev)
> +static inline struct samsung_usbphy_drvdata
> +*samsung_usbphy_get_driver_data(struct platform_device *pdev)
> {
> if (pdev->dev.of_node) {
> const struct of_device_id *match;
> match = of_match_node(samsung_usbphy_dt_match,
> pdev->dev.of_node);
> - return (int) match->data;
> + return (struct samsung_usbphy_drvdata *) match->data;
> }
>
> - return platform_get_device_id(pdev)->driver_data;
> + return (struct samsung_usbphy_drvdata *)
> + platform_get_device_id(pdev)->driver_data;
> }
>
> static int __devinit samsung_usbphy_probe(struct platform_device *pdev)
> {
> struct samsung_usbphy *sphy;
> - struct samsung_usbphy_data *pdata;
> + struct samsung_usbphy_data *pdata = pdev->dev.platform_data;
> struct device *dev =&pdev->dev;
> struct resource *phy_mem;
> void __iomem *phy_base;
> struct clk *clk;
> -
> - pdata = pdev->dev.platform_data;
> - if (!pdata) {
> - dev_err(&pdev->dev, "%s: no platform data defined\n", __func__);
> - return -EINVAL;
> - }
> + int ret;
>
> phy_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> if (!phy_mem) {
> @@ -283,7 +361,19 @@ static int __devinit samsung_usbphy_probe(struct platform_device *pdev)
> return PTR_ERR(clk);
> }
>
> - sphy->dev =&pdev->dev;
> + sphy->dev = dev;
> +
> + if (dev->of_node) {
> + ret = samsung_usbphy_parse_dt_param(sphy);
> + if (ret< 0)
> + return ret;
> + } else {
> + if (!pdata) {
> + dev_err(dev, "no platform data specified\n");
> + return -EINVAL;
> + }
> + }
> +
> sphy->plat = pdata;
> sphy->regs = phy_base;
> sphy->clk = clk;

--

Thanks,
Sylwester


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