On Sat, 05 Jul 2014, Peter Griffin wrote:
> This patch adds the ST glue logic to manage the DWC3 HC
> on STiH407 SoC family. It manages the powerdown signal,
> and configures the internal glue logic and syscfg registers.
>
> Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>
> Signed-off-by: Peter Griffin <peter.griffin@xxxxxxxxxx>
> ---
> drivers/usb/dwc3/Kconfig | 9 ++
> drivers/usb/dwc3/Makefile | 1 +
> drivers/usb/dwc3/dwc3-st.c | 325 +++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 335 insertions(+)
> create mode 100644 drivers/usb/dwc3/dwc3-st.c
>
> diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
> index 8eb996e..6c85c43 100644
> --- a/drivers/usb/dwc3/Kconfig
> +++ b/drivers/usb/dwc3/Kconfig
> @@ -79,6 +79,15 @@ config USB_DWC3_KEYSTONE
> Support of USB2/3 functionality in TI Keystone2 platforms.
> Say 'Y' or 'M' here if you have one such device
>
> +config USB_DWC3_ST
> + tristate "STMicroelectronics Platforms"
> + depends on ARCH_STI && OF
> + default USB_DWC3_HOST
> + help
> + STMicroelectronics SoCs with one DesignWare Core USB3 IP
> + inside (i.e. STiH407).
> + Say 'Y' or 'M' if you have one such device.
> +
> comment "Debugging features"
>
> config USB_DWC3_DEBUG
> diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
> index 10ac3e7..11c9f54 100644
> --- a/drivers/usb/dwc3/Makefile
> +++ b/drivers/usb/dwc3/Makefile
> @@ -33,3 +33,4 @@ obj-$(CONFIG_USB_DWC3_OMAP) += dwc3-omap.o
> obj-$(CONFIG_USB_DWC3_EXYNOS) += dwc3-exynos.o
> obj-$(CONFIG_USB_DWC3_PCI) += dwc3-pci.o
> obj-$(CONFIG_USB_DWC3_KEYSTONE) += dwc3-keystone.o
> +obj-$(CONFIG_USB_DWC3_ST) += dwc3-st.o
> diff --git a/drivers/usb/dwc3/dwc3-st.c b/drivers/usb/dwc3/dwc3-st.c
> new file mode 100644
> index 0000000..2cae9d3
> --- /dev/null
> +++ b/drivers/usb/dwc3/dwc3-st.c
> @@ -0,0 +1,325 @@
> +/**
> + * dwc3-st.c Support for dwc3 platform devices on ST Microelectronics platforms
> + *
> + * This is a small platform driver for the dwc3 to provide the glue logic
> + * to configure the controller. Tested on STi platforms.
Not sure about the use of the term 'platform driver' here and in the
title. We don't normally differentiate. I can find examples to the
contrary, but not many.
> + * Copyright (C) 2014 Stmicroelectronics
> + *
> + * Author: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>
> + * Contributors: Aymen Bouattay <aymen.bouattay@xxxxxx>
> + * Peter Griffin <peter.griffin@xxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * Inspired by dwc3-omap.c and dwc3-exynos.c.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/slab.h>
> +#include <linux/interrupt.h>
> +#include <linux/platform_device.h>
> +#include <linux/ioport.h>
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/delay.h>
> +#include <linux/regmap.h>
> +#include <linux/reset.h>
> +
> +#include "core.h"
> +#include "io.h"
> +
> +/* Reg glue registers */
> +#define USB2_CLKRST_CTRL 0x00
> +#define aux_clk_en(n) ((n)<<0)
> +#define sw_pipew_reset_n(n) ((n)<<4)
> +#define ext_cfg_reset_n(n) ((n)<<8)
> +#define xhci_revision(n) ((n)<<12)
These all need reformatting, see CodingStyle - 3.1: Spaces
#define xhci_revision(n) ((n) << 12)
Lining them up with TABs would make them easier to read.
Also, I don't think there is a requirement to encapsulate the 'n'.
> +#define USB2_VBUS_MNGMNT_SEL1 0x2C
> +/*
> + * 2'b00 : Override value from Reg 0x30 is selected
> + * 2'b01 : utmiotg_vbusvalid from usb3_top top is selected
> + * 2'b10 : pipew_powerpresent from PIPEW instance is selected
> + * 2'b11 : value is 1'b0
> + */
What is this documenting? Isn't documentation meant to make things
clearer? Now I'm just really confused - by the documentation.
> +#define SEL_OVERRIDE_VBUSVALID(n) ((n)<<0)
> +#define SEL_OVERRIDE_POWERPRESENT(n) ((n)<<4)
> +#define SEL_OVERRIDE_BVALID(n) ((n)<<8)
> +
> +#define USB2_VBUS_MNGMNT_VAL1 0x30
> +#define OVERRIDE_VBUSVALID_VAL (1 << 0)
> +#define OVERRIDE_POWERPRESENT_VAL (1 << 4)
> +#define OVERRIDE_BVALID_VAL (1 << 8)
Use BIT() for all of these bit setting macros.
> +/* Static DRD configuration */
> +#define USB_HOST_DEFAULT_MASK 0xffe
> +#define USB_SET_PORT_DEVICE 0x1
> +
> +struct st_dwc3 {
> + struct platform_device *dwc3; /* platform device pointer */
> + struct device *dev; /* device pointer */
> + void __iomem *glue_base; /* ioaddr for programming the glue */
> + struct regmap *regmap; /* regmap for getting syscfg */
> + int syscfg_reg_off; /* usb syscfg control offset */
> + bool drd_device_conf; /* DRD static host/device conf */
> + struct reset_control *rstc_pwrdn;/* Rst control for powerdown*/
> +};
This is a mess. Use kerneldoc formatting instead.
> +static inline u32 st_dwc3_readl(void __iomem *base, u32 offset)
> +{
> + return readl_relaxed(base + offset);
> +}
> +
> +static inline void st_dwc3_writel(void __iomem *base, u32 offset, u32 value)
> +{
> + writel_relaxed(value, base + offset);
> +}
Why are these being abstracted?
Just use {read,write}l_relaxed() directly.
> +/**
> + * st_dwc3_drd_init: program the port
> + * @dwc3_data: driver private structure
> + * Description: this function is to program the port as either host or device
> + * according to the static configuration passed from devicetree.
> + * OTG and dual role are not yet supported!
> + */
> +static int st_dwc3_drd_init(struct st_dwc3 *dwc3_data)
> +{
> + u32 val;
> +
> + regmap_read(dwc3_data->regmap, dwc3_data->syscfg_reg_off, &val);
Shouldn't you be checking the return value of regmap_read()?
> + if (dwc3_data->drd_device_conf)
> + val |= USB_SET_PORT_DEVICE;
> + else
> + val &= USB_HOST_DEFAULT_MASK;
> +
> + return regmap_write(dwc3_data->regmap, dwc3_data->syscfg_reg_off, val);
> +}
> +
> +/**
> + * st_dwc3_init: init the controller via glue logic
> + * @dwc3_data: driver private structure
> + */
> +static void st_dwc3_init(struct st_dwc3 *dwc3_data)
> +{
> + u32 reg = st_dwc3_readl(dwc3_data->glue_base, USB2_CLKRST_CTRL);
> +
> + reg |= aux_clk_en(1) | ext_cfg_reset_n(1) | xhci_revision(1);
> + reg &= ~sw_pipew_reset_n(1);
1? Better to add defines for these magic numbers. What is 1 anyway?
Port one? If so, shouldn't this function be called
st_dwc2_init_port_one(), or similar?
> + st_dwc3_writel(dwc3_data->glue_base, USB2_CLKRST_CTRL, reg);
> +
> + reg = st_dwc3_readl(dwc3_data->glue_base, USB2_VBUS_MNGMNT_SEL1);
> + reg |= SEL_OVERRIDE_VBUSVALID(1) | SEL_OVERRIDE_POWERPRESENT(1) |
> + SEL_OVERRIDE_BVALID(1);
> + st_dwc3_writel(dwc3_data->glue_base, USB2_VBUS_MNGMNT_SEL1, reg);
> + udelay(100);
Why 100?
> + reg = st_dwc3_readl(dwc3_data->glue_base, USB2_CLKRST_CTRL);
> + reg |= sw_pipew_reset_n(1);
> + st_dwc3_writel(dwc3_data->glue_base, USB2_CLKRST_CTRL, reg);
> +}
> +
> +static void st_dwc3_dt_get_pdata(struct platform_device *pdev,
> + struct st_dwc3 *dwc3_data)
> +{
> + struct device_node *np = pdev->dev.of_node;
> +
> + dwc3_data->drd_device_conf =
> + of_property_read_bool(np, "st,dwc3-drd-device");
This requires a DT Ack.
> +}
> +
> +/**
> + * st_dwc3_probe: main probe function
> + * @pdev: platform_device
> + * Description: this is the probe function that gets all the resources to manage
> + * the glue-logic, setup the controller and take out of powerdown.
> + */
I've never seen .probe() documented before? I think you can safely
remove this kerneldoc header.
> +static int st_dwc3_probe(struct platform_device *pdev)
> +{
> + struct platform_device *dwc3;
> + struct st_dwc3 *dwc3_data;
> + struct resource *res;
> + struct device *dev = &pdev->dev;
> + struct device_node *node = dev->of_node;
> + struct regmap *regmap;
> + int ret = 0;
No need to initialise.
> + if (!node) {
> + dev_err(dev, "device node not found\n");
> + return -EINVAL;
> + }
Remove this and make the driver depend on OF.
> + dwc3_data = devm_kzalloc(dev, sizeof(*dwc3_data), GFP_KERNEL);
> + if (!dwc3_data)
> + return -ENOMEM;
> +
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "reg-glue");
> + if (!res)
> + return -ENXIO;
No need to check res here, devm_request_and_ioremap() does it for you.
> + dwc3_data->glue_base = devm_request_and_ioremap(dev, res);
> + if (!dwc3_data->glue_base)
> + return -EADDRNOTAVAIL;
What? Better to return the value from devm_request_and_ioremap() than
make up your own.
> + regmap = syscon_regmap_lookup_by_phandle(node, "st,syscfg");
> + if (IS_ERR(regmap))
> + return PTR_ERR(regmap);
> +
> + dwc3 = platform_device_alloc("st-dwc3", PLATFORM_DEVID_AUTO);
> + if (!dwc3) {
> + dev_err(&pdev->dev, "couldn't allocate dwc3 device\n");
> + return -ENOMEM;
> + }
I'm confused. What is this doing? Isn't this the DWC3 driver, which
already had a platform device structure associated to it? Perhaps a
small ASCII diagram describing the layers might be useful.
> + dma_set_coherent_mask(&dwc3->dev, dev->coherent_dma_mask);
> +
> + dwc3->dev.parent = &pdev->dev;
> + dwc3->dev.dma_mask = pdev->dev.dma_mask;
> + dwc3->dev.dma_parms = pdev->dev.dma_parms;
> +
> + dwc3_data->dwc3 = dwc3;
> + dwc3_data->dev = &pdev->dev;
We're saving this twice, it's already available in dwc3, which we just
saved.
> + dwc3_data->regmap = regmap;
> +
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "syscfg-reg");
> + if (!res) {
> + ret = -ENXIO;
> + goto undo_platform_dev_alloc;
> + }
> +
> + dwc3_data->syscfg_reg_off = res->start;
> +
> + dev_info(&pdev->dev, "glue-logic addr 0x%p, syscfg-reg offset 0x%x\n",
> + dwc3_data->glue_base, dwc3_data->syscfg_reg_off);
I think this should be removed. At the very least downgraded to
dev_dbg().
> + dwc3_data->rstc_pwrdn = devm_reset_control_get(dwc3_data->dev, NULL);
> + if (IS_ERR(dwc3_data->rstc_pwrdn)) {
> + dev_err(&pdev->dev, "could not get reset controller\n");
> + ret = PTR_ERR(dwc3_data->rstc_pwrdn);
> + goto undo_platform_dev_alloc;
> + }
> +
> + /* Manage PowerDown */
> + reset_control_deassert(dwc3_data->rstc_pwrdn);
> +
> + st_dwc3_dt_get_pdata(pdev, dwc3_data);
As there is only one line in this function and this driver is DT only,
I would bring that line directly into .probe().
> + /* Allocate and initialize the core */
> + ret = of_platform_populate(node, NULL, NULL, dev);
> + if (ret) {
> + dev_err(dev, "failed to add dwc3 core\n");
> + goto undo_powerdown;
> + }
> +
> + /*
> + * Configure the USB port as device or host according to the static
> + * configuration passed from the platform.
> + * DRD is the only mode currently supported so this will be enhanced
> + * later as soon as OTG will be available.
> + */
> + ret = st_dwc3_drd_init(dwc3_data);
> + if (ret) {
> + dev_err(dev, "st_dwc3_drd_init failed\n");
I wouldn't have names of functions in the kernel log.
Swap out for something like "initialisation failed\n"
> + goto undo_powerdown;
> + }
> +
> + dev_info(&pdev->dev, "configured as %s DRD\n",
> + dwc3_data->drd_device_conf ? "device" : "host");
> +
> + /* ST glue logic init */
> + st_dwc3_init(dwc3_data);
Can this fail?
> + ret = platform_device_add_resources(dwc3_data->dwc3, pdev->resource,
> + pdev->num_resources);
> + if (ret) {
> + dev_err(&pdev->dev, "couldn't add resources to dwc3 device\n");
> + goto undo_powerdown;
> + }
> +
> + ret = platform_device_add(dwc3_data->dwc3);
> + if (ret) {
> + dev_err(&pdev->dev, "failed to register dwc3 device\n");
> + goto undo_powerdown;
> + }
> +
> + platform_set_drvdata(pdev, dwc3_data);
> +
> + return 0;
> +
> +undo_powerdown:
> + reset_control_assert(dwc3_data->rstc_pwrdn);
> +undo_platform_dev_alloc:
> + platform_device_put(pdev);
> +
> + return ret;
> +
Remove the '\n' here.
> +}
> +
> +static int st_dwc3_remove(struct platform_device *pdev)
> +{
> + struct st_dwc3 *dwc3_data = platform_get_drvdata(pdev);
> +
> + platform_device_unregister(dwc3_data->dwc3);
> +
> + return 0;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int st_dwc3_suspend(struct device *dev)
> +{
> + struct st_dwc3 *dwc3_data = dev_get_drvdata(dev);
> +
> + reset_control_assert(dwc3_data->rstc_pwrdn);
> +
> + pinctrl_pm_select_sleep_state(dev);
> +
> + return 0;
> +}
> +
> +static int st_dwc3_resume(struct device *dev)
> +{
> + struct st_dwc3 *dwc3_data = dev_get_drvdata(dev);
> +
> + pinctrl_pm_select_default_state(dev);
> +
> + reset_control_deassert(dwc3_data->rstc_pwrdn);
> +
> + return 0;
> +}
> +
Remove the '\n' here.
> +#endif /* CONFIG_PM_SLEEP */
> +
> +static const struct dev_pm_ops st_dwc3_dev_pm_ops = {
> + SET_SYSTEM_SLEEP_PM_OPS(st_dwc3_suspend, st_dwc3_resume)
> +};
Use SIMPLE_DEV_PM_OPS().
> +static struct of_device_id st_dwc3_match[] = {
> + { .compatible = "st,stih407-dwc3" },
> + { /* sentinel */ },
> +};
> +
> +MODULE_DEVICE_TABLE(of, st_dwc3_match);
> +
> +static struct platform_driver st_dwc3_driver = {
> + .probe = st_dwc3_probe,
> + .remove = st_dwc3_remove,
> + .driver = {
> + .name = "usb-st-dwc3",
> + .owner = THIS_MODULE,
This is done for you elese where, you can remove.
> + .of_match_table = of_match_ptr(st_dwc3_match),
> + .pm = &st_dwc3_dev_pm_ops,
> + },
> +};
> +
> +module_platform_driver(st_dwc3_driver);
> +
> +MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>");
> +MODULE_DESCRIPTION("DesignWare USB3 STi Glue Layer");
> +MODULE_LICENSE("GPL v2");
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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