[PATCH] usb: phy: samsung: Introducing usb phy driver for hsotg
Kukjin Kim
kgene.kim at samsung.com
Wed Oct 17 07:00:00 EDT 2012
Praveen Paneri wrote:
>
> platform_set_drvdata() required for driver's remove function, so adding
> it back.
>
> From v6:
> Added TODO for phy bindings with controller
> Dropped platform_set_drvdata() from driver probe
>
> This driver uses usb_phy interface to interact with s3c-hsotg. Supports
> phy_init and phy_shutdown functions to enable/disable phy. Tested with
> smdk6410 and smdkv310. More SoCs can be brought under later.
>
> Signed-off-by: Praveen Paneri <p.paneri at samsung.com>
> Acked-by: Heiko Stuebner <heiko at sntech.de>
> ---
> .../devicetree/bindings/usb/samsung-usbphy.txt | 11 +
> drivers/usb/phy/Kconfig | 8 +
> drivers/usb/phy/Makefile | 1 +
> drivers/usb/phy/samsung-usbphy.c | 357
++++++++++++++++++++
> include/linux/platform_data/samsung-usbphy.h | 27 ++
> 5 files changed, 404 insertions(+), 0 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/usb/samsung-
> usbphy.txt
> create mode 100644 drivers/usb/phy/samsung-usbphy.c
> create mode 100644 include/linux/platform_data/samsung-usbphy.h
>
> diff --git a/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
> b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
> new file mode 100644
> index 0000000..7b26e2d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/usb/samsung-usbphy.txt
> @@ -0,0 +1,11 @@
> +* Samsung's usb phy transceiver
> +
> +The Samsung's phy transceiver is used for controlling usb otg phy for
> +s3c-hsotg usb device controller.
> +TODO: Adding the PHY binding with controller(s) according to the under
> +developement generic PHY driver.
> +
> +Required properties:
> +- compatible : should be "samsung,exynos4210-usbphy"
> +- reg : base physical address of the phy registers and length of memory
> mapped
> + region.
> diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
> index 63c339b..313685f 100644
> --- a/drivers/usb/phy/Kconfig
> +++ b/drivers/usb/phy/Kconfig
> @@ -32,3 +32,11 @@ config MV_U3D_PHY
> help
> Enable this to support Marvell USB 3.0 phy controller for Marvell
> SoC.
> +
> +config SAMSUNG_USBPHY
> + bool "Samsung USB PHY controller Driver"
> + depends on USB_S3C_HSOTG
> + select USB_OTG_UTILS
> + help
> + Enable this to support Samsung USB phy controller for samsung
> + SoCs.
> diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
> index b069f29..55dcfc1 100644
> --- a/drivers/usb/phy/Makefile
> +++ b/drivers/usb/phy/Makefile
> @@ -8,3 +8,4 @@ obj-$(CONFIG_OMAP_USB2) +=
omap-usb2.o
> obj-$(CONFIG_USB_ISP1301) += isp1301.o
> obj-$(CONFIG_MV_U3D_PHY) += mv_u3d_phy.o
> obj-$(CONFIG_USB_EHCI_TEGRA) += tegra_usb_phy.o
> +obj-$(CONFIG_SAMSUNG_USBPHY) += samsung-usbphy.o
> diff --git a/drivers/usb/phy/samsung-usbphy.c b/drivers/usb/phy/samsung-
> usbphy.c
> new file mode 100644
> index 0000000..14c182f
> --- /dev/null
> +++ b/drivers/usb/phy/samsung-usbphy.c
Hi,
Basically I agree and this is a good approach to support usb phy for Samsung
stuff...but there are some comments ;)
> @@ -0,0 +1,357 @@
> +/* linux/drivers/usb/phy/samsung-usbphy.c
> + *
> + * Copyright (c) 2012 Samsung Electronics Co., Ltd.
> + * http://www.samsung.com
> + *
> + * Author: Praveen Paneri <p.paneri at samsung.com>
> + *
> + * Samsung USB2.0 High-speed OTG transceiver, talks to S3C HS OTG
> controller
> + *
> + * 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.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/usb/otg.h>
> +#include <linux/platform_data/samsung-usbphy.h>
> +
> +/* Register definitions */
> +
> +#define S3C_PHYPWR (0x00)
> +
IMHO, according to the file name, samsung-usbphy, SAMSUNG_ is better here?
> +#define S3C_PHYPWR_NORMAL_MASK (0x19 << 0)
> +#define S3C_PHYPWR_OTG_DISABLE (1 << 4)
> +#define S3C_PHYPWR_ANALOG_POWERDOWN (1 << 3)
> +#define S3C_PHYPWR_FORCE_SUSPEND (1 << 1)
> +/* For Exynos4 */
> +#define EXYNOS4_PHYPWR_NORMAL_MASK (0x39 << 0)
Hmm...is this right? If so, need to use exact name for the definition.
See arch/arm/mach-exynos/include/mach/regs-usb-phy.h
> +#define EXYNOS4_PHYPWR_SLEEP (1 << 5)
Ditto.
> +
> +#define S3C_PHYCLK (0x04)
> +
> +#define S3C_PHYCLK_MODE_SERIAL (1 << 6)
MODE_USB11?
> +#define S3C_PHYCLK_EXT_OSC (1 << 5)
> +#define S3C_PHYCLK_COMMON_ON_N (1 << 4)
There are Samsung SoCs which is having two PHYs, so I think, we need to
design this with considering it.
> +#define S3C_PHYCLK_ID_PULL (1 << 2)
> +#define S3C_PHYCLK_CLKSEL_MASK (0x3 << 0)
> +#define S3C_PHYCLK_CLKSEL_SHIFT (0)
> +#define S3C_PHYCLK_CLKSEL_48M (0x0 << 0)
> +#define S3C_PHYCLK_CLKSEL_12M (0x2 << 0)
> +#define S3C_PHYCLK_CLKSEL_24M (0x3 << 0)
As you know, the values for CLKSEL are different on each Samsung SoCs...if
we use this patch, we need to implement for other SoCs many things. In
addition, this patch says can support EXYNOS4210 but not actually...
> +
> +#define S3C_RSTCON (0x08)
> +
> +#define S3C_RSTCON_PHYCLK (1 << 2)
> +#define S3C_RSTCON_HCLK (1 << 1)
> +#define S3C_RSTCON_PHY (1 << 0)
> +
> +#ifndef MHZ
> +#define MHZ (1000*1000)
> +#endif
> +
> +enum samsung_cpu_type {
> + TYPE_S3C64XX,
> + TYPE_EXYNOS4210,
> +};
> +
> +/*
> + * 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
> + * @ref_clk_freq: reference clock frequency selection
> + * @cpu_type: machine identifier
> + */
> +struct samsung_usbphy {
> + struct usb_phy phy;
> + struct samsung_usbphy_data *plat;
> + struct device *dev;
> + struct clk *clk;
> + void __iomem *regs;
> + int ref_clk_freq;
> + int cpu_type;
> +};
> +
> +#define phy_to_sphy(x) container_of((x), struct
samsung_usbphy,
> phy)
> +
> +/*
> + * Returns reference clock frequency selection value
> + */
> +static int samsung_usbphy_get_refclk_freq(struct samsung_usbphy *sphy)
> +{
> + struct clk *ref_clk;
> + int refclk_freq = 0;
> +
> + ref_clk = clk_get(sphy->dev, "xusbxti");
> + if (IS_ERR(ref_clk)) {
IS_ERR_OR_NULL(ref_clk)?
> + dev_err(sphy->dev, "Failed to get reference clock\n");
> + return PTR_ERR(ref_clk);
> + }
> +
> + switch (clk_get_rate(ref_clk)) {
> + case 12 * MHZ:
> + refclk_freq |= S3C_PHYCLK_CLKSEL_12M;
Just,
+ refclk_freq = S3C_PHYCLK_CLKSEL_12M;
because its defalut value is 0...BTW, how do you think to support other SoCs
such as EXYNOS4210, EXYNOS4X12?
> + break;
> + case 24 * MHZ:
> + refclk_freq |= S3C_PHYCLK_CLKSEL_24M;
Ditto.
> + break;
> + default:
> + case 48 * MHZ:
> + /* default reference clock */
> + refclk_freq |= S3C_PHYCLK_CLKSEL_48M;
Ditto...and default refernec clock for EXYNOS4 is 24MHz...
> + break;
> + }
> + clk_put(ref_clk);
> +
> + return refclk_freq;
> +}
> +
Hmm...I need more time to look at this again...
Thanks.
Best regards,
Kgene.
--
Kukjin Kim <kgene.kim at samsung.com>, Senior Engineer,
SW Solution Development Team, Samsung Electronics Co., Ltd.
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