Re: [PATCH V6 04/12] phy: st-miphy40lp: Add skeleton driver

From: Kishon Vijay Abraham I
Date: Tue Feb 11 2014 - 06:35:46 EST


Hi,

On Tuesday 11 February 2014 03:00 PM, Mohit Kumar wrote:
> From: Pratyush Anand <pratyush.anand@xxxxxx>
>
> ST miphy40lp supports PCIe, SATA and Super Speed USB. This driver adds
> skeleton support for the same.
>
> This skeleton defines function corresponding to phy ops as well as sleep
> pm ops. Any platform using this phy can add its own platform specific
> ops(if needed) corresponding to each phy ops.
>
> Phy specific modifications will require phy register space, which is
> passed from DT as a resource. Currently only SPEAr1310 and SPEAr1340 are
> known user of this phy, which do not need to modify phy registers
> normally. Therefore we have not retrieved phy base address from DT and
> hence not io-remapped it. However, same can be added in future if
> required.
>
> SoC specific modifications should be done in plat specific ops and phy
> specific modifications should be done in phy ops itself. As a general
> rule, follow the convention of modifying misc reg space in plat ops and
> phy reg space in phy ops.
>
> Signed-off-by: Pratyush Anand <pratyush.anand@xxxxxx>
> Tested-by: Mohit Kumar <mohit.kumar@xxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Viresh Kumar <viresh.linux@xxxxxxxxx>
> Cc: Kishon Vijay Abraham I <kishon@xxxxxx>
> Cc: spear-devel@xxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> ---
> drivers/phy/Kconfig | 7 ++
> drivers/phy/Makefile | 1 +
> drivers/phy/phy-miphy40lp.c | 234 +++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 242 insertions(+), 0 deletions(-)
> create mode 100644 drivers/phy/phy-miphy40lp.c
>
> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
> index afa2354..ed5b4f3 100644
> --- a/drivers/phy/Kconfig
> +++ b/drivers/phy/Kconfig
> @@ -64,4 +64,11 @@ config BCM_KONA_USB2_PHY
> help
> Enable this to support the Broadcom Kona USB 2.0 PHY.
>
> +config PHY_ST_MIPHY40LP
> + tristate "ST MIPHY 40LP driver"
> + select GENERIC_PHY
> + help
> + Support for ST MIPHY 40LP which can be used for PCIe, SATA and Super Speed USB.
> + SPEAr13xx SoCs have used this PHY internally for PCIe and SATA implementation.
> +
> endmenu
> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
> index b57c253..c061091 100644
> --- a/drivers/phy/Makefile
> +++ b/drivers/phy/Makefile
> @@ -9,3 +9,4 @@ obj-$(CONFIG_PHY_EXYNOS_MIPI_VIDEO) += phy-exynos-mipi-video.o
> obj-$(CONFIG_PHY_MVEBU_SATA) += phy-mvebu-sata.o
> obj-$(CONFIG_OMAP_USB2) += phy-omap-usb2.o
> obj-$(CONFIG_TWL4030_USB) += phy-twl4030-usb.o
> +obj-$(CONFIG_PHY_ST_MIPHY40LP) += phy-miphy40lp.o
> diff --git a/drivers/phy/phy-miphy40lp.c b/drivers/phy/phy-miphy40lp.c
> new file mode 100644
> index 0000000..98859ff
> --- /dev/null
> +++ b/drivers/phy/phy-miphy40lp.c
> @@ -0,0 +1,234 @@
> +/*
> + * ST MiPHY-40LP PHY driver
> + *
> + * Copyright (C) 2014 ST Microelectronics
> + * Pratyush Anand <pratyush.anand@xxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/phy/phy.h>
> +#include <linux/regmap.h>
> +
> +enum phy_mode {
miphy40lp_phy_mode?
> + SATA,
> + PCIE,
> + SS_USB,
> +};
> +
> +struct miphy40lp_priv;
> +
> +/* platform specific function struct */
> +struct miphy40lp_plat_ops {
> + int (*plat_init)(struct miphy40lp_priv *priv);
> + int (*plat_exit)(struct miphy40lp_priv *priv);
> + int (*plat_power_off)(struct miphy40lp_priv *priv);
> + int (*plat_power_on)(struct miphy40lp_priv *priv);
> + int (*plat_suspend)(struct miphy40lp_priv *priv);
> + int (*plat_resume)(struct miphy40lp_priv *priv);
> +};
> +
> +struct miphy40lp_priv {
> + /* regmap for any soc specific misc registers */
> + struct regmap *misc;
> + /* phy struct pointer */
> + struct phy *phy;
> + /* phy mode: 0 for SATA 1 for PCIe and 2 for SS-USB */
> + enum phy_mode mode;
> + /* instance id of this phy */
> + u32 id;
> + /* platform specific callbacks */
> + const struct miphy40lp_plat_ops *plat_ops;
> +};
> +
> +static int miphy40lp_init(struct phy *phy)
> +{
> + struct miphy40lp_priv *priv = phy_get_drvdata(phy);
> + const struct miphy40lp_plat_ops *ops = priv->plat_ops;
> + int ret = 0;
> +
> + if (ops && ops->plat_init)
> + ret = ops->plat_init(priv);
> +
> + return ret;
> +}
> +
> +static int miphy40lp_exit(struct phy *phy)
> +{
> + struct miphy40lp_priv *priv = phy_get_drvdata(phy);
> + const struct miphy40lp_plat_ops *ops = priv->plat_ops;
> + int ret = 0;
> +
> + if (ops && ops->plat_exit)
> + ret = ops->plat_exit(priv);
> +
> + return ret;
> +}
> +
> +static int miphy40lp_power_off(struct phy *phy)
> +{
> + struct miphy40lp_priv *priv = phy_get_drvdata(phy);
> + const struct miphy40lp_plat_ops *ops = priv->plat_ops;
> + int ret = 0;
> +
> + if (ops && ops->plat_init)
> + ret = ops->plat_init(priv);

plat_power_off here..
> +
> + return ret;
> +}
> +
> +static int miphy40lp_power_on(struct phy *phy)
> +{
> + struct miphy40lp_priv *priv = phy_get_drvdata(phy);
> + const struct miphy40lp_plat_ops *ops = priv->plat_ops;
> + int ret = 0;
> +
> + if (ops && ops->plat_power_on)
> + ret = ops->plat_power_on(priv);
> +
> + return ret;
> +}
> +
> +static const struct of_device_id miphy40lp_of_match[] = {
> + { .compatible = "st,miphy40lp-phy", .data = NULL },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, miphy40lp_of_match);
> +
> +static struct phy_ops miphy40lp_ops = {
> + .init = miphy40lp_init,
> + .exit = miphy40lp_exit,
> + .power_off = miphy40lp_power_off,
> + .power_on = miphy40lp_power_on,
> + .owner = THIS_MODULE,
> +};
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int miphy40lp_suspend(struct device *dev)
> +{
> + struct miphy40lp_priv *priv = dev_get_drvdata(dev);
> + const struct miphy40lp_plat_ops *ops = priv->plat_ops;
> + int ret = 0;
> +
> + if (ops && ops->plat_suspend)
> + ret = ops->plat_suspend(priv);
> +
> + return ret;
> +}
> +
> +static int miphy40lp_resume(struct device *dev)
> +{
> + struct miphy40lp_priv *priv = dev_get_drvdata(dev);
> + const struct miphy40lp_plat_ops *ops = priv->plat_ops;
> + int ret = 0;
> +
> + if (ops && ops->plat_resume)
> + ret = ops->plat_resume(priv);
> +
> + return ret;
> +}
> +#endif
> +
> +static SIMPLE_DEV_PM_OPS(miphy40lp_pm_ops, miphy40lp_suspend,
> + miphy40lp_resume);
> +
> +static struct phy *miphy40lp_xlate(struct device *dev,
> + struct of_phandle_args *args)
> +{
> + struct miphy40lp_priv *priv = dev_get_drvdata(dev);
> +
> + if (args->args_count < 1) {
> + dev_err(dev, "DT did not pass correct no of args\n");
> + return NULL;
> + }
> +
> + priv->mode = args->args[0];

Lets add error checking here if the mode is incorrect.

Thanks
Kishon
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