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References: <1496225523-22035-1-git-send-email-raviteja.garimella@broadcom.com>
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 <f90cd885-be89-5c66-c5d8-224173825f0c@ti.com> <CAEHZuqMJyxCdNmv2RZ9ZOc=FuWRQesfJ9-QMQCKW+XHUQru6wg@mail.gmail.com>
From: Raviteja Garimella <raviteja.garimella@broadcom.com>
Date: Fri, 2 Jun 2017 17:21:37 +0530
Message-ID: <CAEHZuqMVV_TmTqZk=w-y2naeU0PAO4=vO5R_oHZwgwe5KzDHtw@mail.gmail.com>
Subject: Re: [PATCH v6 2/3] phy:phy-bcm-ns2-usbdrd:Broadcom USB DRD Phy driver
 for Northstar2
To: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Rob Herring <robh+dt@kernel.org>, Mark Rutland <mark.rutland@arm.com>,
        Ray Jui <rjui@broadcom.com>, Scott Branden <sbranden@broadcom.com>,
        Jon Mason <jonmason@broadcom.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will.deacon@arm.com>, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        BCM Kernel Feedback <bcm-kernel-feedback-list@broadcom.com>,
        linux-arm-kernel@lists.infradead.org
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Sender: linux-kernel-owner@vger.kernel.org
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Hi,

On Fri, Jun 2, 2017 at 5:18 PM, Raviteja Garimella
<raviteja.garimella@broadcom.com> wrote:
> Hi Kishon,
>
> On Fri, Jun 2, 2017 at 3:59 PM, Kishon Vijay Abraham I <kishon@ti.com> wrote:
>> Hi,
>>
>> On Wednesday 31 May 2017 03:42 PM, Raviteja Garimella wrote:
>>> This is driver for USB DRD Phy used in Broadcom's Northstar2
>>> SoC. The phy can be configured to be in Device mode or Host
>>> mode based on the type of cable connected to the port. The
>>> driver registers to  extcon framework to get appropriate
>>> connect events for Host/Device cables connect/disconnect
>>> states based on VBUS and ID interrupts.
>>>
>>> Signed-off-by: Raviteja Garimella <raviteja.garimella@broadcom.com>
>>> ---
>>>  drivers/phy/Kconfig              |  13 ++
>>>  drivers/phy/Makefile             |   1 +
>>>  drivers/phy/phy-bcm-ns2-usbdrd.c | 466 +++++++++++++++++++++++++++++++++++++++
>>>  3 files changed, 480 insertions(+)
>>>  create mode 100644 drivers/phy/phy-bcm-ns2-usbdrd.c
>>>
>>> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
>>> index afaf7b6..8028da7 100644
>>> --- a/drivers/phy/Kconfig
>>> +++ b/drivers/phy/Kconfig
>>> @@ -507,6 +507,19 @@ config PHY_CYGNUS_PCIE
>>>         Enable this to support the Broadcom Cygnus PCIe PHY.
>>>         If unsure, say N.
>>>
>>> +config PHY_NS2_USB_DRD
>>> +     tristate "Broadcom Northstar2 USB DRD PHY support"
>>> +     depends on OF && (ARCH_BCM_IPROC || COMPILE_TEST)
>>> +     select GENERIC_PHY
>>> +     select EXTCON
>>> +     default ARCH_BCM_IPROC
>>> +     help
>>> +       Enable this to support the Broadcom Northstar2 USB DRD PHY.
>>> +       This driver initializes the PHY in either HOST or DEVICE mode.
>>> +       The host or device configuration is read from device tree.
>>> +
>>> +       If unsure, say N.
>>> +
>>>  source "drivers/phy/tegra/Kconfig"
>>>
>>>  config PHY_NS2_PCIE
>>> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
>>> index f8047b4..e5fbb0e 100644
>>> --- a/drivers/phy/Makefile
>>> +++ b/drivers/phy/Makefile
>>> @@ -61,6 +61,7 @@ obj-$(CONFIG_PHY_TUSB1210)          += phy-tusb1210.o
>>>  obj-$(CONFIG_PHY_BRCM_SATA)          += phy-brcm-sata.o
>>>  obj-$(CONFIG_PHY_PISTACHIO_USB)              += phy-pistachio-usb.o
>>>  obj-$(CONFIG_PHY_CYGNUS_PCIE)                += phy-bcm-cygnus-pcie.o
>>> +obj-$(CONFIG_PHY_NS2_USB_DRD)                += phy-bcm-ns2-usbdrd.o
>>>  obj-$(CONFIG_ARCH_TEGRA) += tegra/
>>>  obj-$(CONFIG_PHY_NS2_PCIE)           += phy-bcm-ns2-pcie.o
>>>  obj-$(CONFIG_PHY_MESON8B_USB2)               += phy-meson8b-usb2.o
>>> diff --git a/drivers/phy/phy-bcm-ns2-usbdrd.c b/drivers/phy/phy-bcm-ns2-usbdrd.c
>>> new file mode 100644
>>> index 0000000..8e05c70
>>> --- /dev/null
>>> +++ b/drivers/phy/phy-bcm-ns2-usbdrd.c
>>> @@ -0,0 +1,466 @@
>>> +/*
>>> + * Copyright (C) 2017 Broadcom
>>> + *
>>> + * 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 version 2.
>>> + *
>>> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
>>> + * kind, whether express or implied; without even the implied warranty
>>> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>>> + * GNU General Public License for more details.
>>> + */
>>> +
>>> +#include <linux/delay.h>
>>> +#include <linux/extcon.h>
>>> +#include <linux/gpio.h>
>>> +#include <linux/gpio/consumer.h>
>>> +#include <linux/init.h>
>>> +#include <linux/interrupt.h>
>>> +#include <linux/io.h>
>>> +#include <linux/irq.h>
>>> +#include <linux/mfd/syscon.h>
>>> +#include <linux/module.h>
>>> +#include <linux/of.h>
>>> +#include <linux/of_address.h>
>>> +#include <linux/phy/phy.h>
>>> +#include <linux/platform_device.h>
>>> +#include <linux/regmap.h>
>>> +#include <linux/slab.h>
>>> +#include <linux/workqueue.h>
>>> +
>>> +#define ICFG_DRD_AFE         0x0
>>> +#define ICFG_MISC_STAT               0x18
>>> +#define ICFG_DRD_P0CTL               0x1C
>>> +#define ICFG_STRAP_CTRL              0x20
>>> +#define ICFG_FSM_CTRL                0x24
>>> +
>>> +#define ICFG_DEV_BIT         BIT(2)
>>> +#define IDM_RST_BIT          BIT(0)
>>> +#define AFE_CORERDY_VDDC     BIT(18)
>>> +#define PHY_PLL_RESETB               BIT(15)
>>> +#define PHY_RESETB           BIT(14)
>>> +#define PHY_PLL_LOCK         BIT(0)
>>> +
>>> +#define DRD_DEV_MODE         BIT(20)
>>> +#define OHCI_OVRCUR_POL              BIT(11)
>>> +#define ICFG_OFF_MODE                BIT(6)
>>> +#define PLL_LOCK_RETRY               1000
>>> +
>>> +#define EVT_DEVICE           0
>>> +#define EVT_HOST             1
>>> +
>>> +#define DRD_HOST_MODE                (BIT(2) | BIT(3))
>>> +#define DRD_DEVICE_MODE              (BIT(4) | BIT(5))
>>> +#define DRD_HOST_VAL         0x803
>>> +#define DRD_DEV_VAL          0x807
>>> +#define GPIO_DELAY           20
>>> +
>>> +struct ns2_phy_data;
>>> +struct ns2_phy_driver {
>>> +     void __iomem *icfgdrd_regs;
>>> +     void __iomem *idmdrd_rst_ctrl;
>>> +     void __iomem *crmu_usb2_ctrl;
>>> +     void __iomem *usb2h_strap_reg;
>>> +     struct ns2_phy_data *data;
>>> +     struct extcon_specific_cable_nb extcon_dev;
>>> +     struct extcon_specific_cable_nb extcon_host;
>>
>> The above two members are not used in the driver.
>
> Missed out to remove them. Will do.
>
>>> +     struct extcon_dev *edev;
>>
>> Does USB DRD driver waits for extcon events? If not using extcon here is bogus.
>
> DRD driver uses extcon events to disconnect/connect gadget driver runtime.

I meant USB Device controller driver. It's not capable of DRD.

Thanks,
Ravi

>
>>> +     struct gpio_desc *vbus_gpiod;
>>> +     struct gpio_desc *id_gpiod;
>>> +     int id_irq;
>>> +     int vbus_irq;
>>> +     unsigned long debounce_jiffies;
>>> +     struct delayed_work wq_extcon;
>>> +};
>>> +
>>> +struct ns2_phy_data {
>>> +     struct ns2_phy_driver *driver;
>>> +     struct phy *phy;
>>> +     int new_state;
>>> +};
>>> +
>>> +static const unsigned int usb_extcon_cable[] = {
>>> +     EXTCON_USB,
>>> +     EXTCON_USB_HOST,
>>> +     EXTCON_NONE,
>>> +};
>>> +
>>> +static inline int pll_lock_stat(u32 usb_reg, int reg_mask,
>>> +                             struct ns2_phy_driver *driver)
>>> +{
>>> +     int retry = PLL_LOCK_RETRY;
>>> +     u32 val;
>>> +
>>> +     do {
>>> +             udelay(1);
>>> +             val = readl(driver->icfgdrd_regs + usb_reg);
>>> +             if (val & reg_mask)
>>> +                     return 0;
>>> +     } while (--retry > 0);
>>> +
>>> +     return -EBUSY;
>>> +}
>>> +
>>> +static int ns2_drd_phy_init(struct phy *phy)
>>> +{
>>> +     struct ns2_phy_data *data = phy_get_drvdata(phy);
>>> +     struct ns2_phy_driver *driver = data->driver;
>>> +     u32 val;
>>> +
>>> +     val = readl(driver->icfgdrd_regs + ICFG_FSM_CTRL);
>>> +
>>> +     if (data->new_state == EVT_HOST) {
>>> +             val &= ~DRD_DEVICE_MODE;
>>> +             val |= DRD_HOST_MODE;
>>> +     } else {
>>> +             val &= ~DRD_HOST_MODE;
>>> +             val |= DRD_DEVICE_MODE;
>>> +     }
>>> +     writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
>>> +
>>> +     return 0;
>>> +}
>>> +
>>> +static int ns2_drd_phy_shutdown(struct phy *phy)
>>> +{
>>> +     struct ns2_phy_data *data = phy_get_drvdata(phy);
>>> +     struct ns2_phy_driver *driver = data->driver;
>>> +     u32 val;
>>> +
>>> +     val = readl(driver->crmu_usb2_ctrl);
>>> +     val &= ~AFE_CORERDY_VDDC;
>>> +     writel(val, driver->crmu_usb2_ctrl);
>>> +
>>> +     val = readl(driver->crmu_usb2_ctrl);
>>> +     val &= ~DRD_DEV_MODE;
>>> +     writel(val, driver->crmu_usb2_ctrl);
>>> +
>>> +     /* Disable Host and Device Mode */
>>> +     val = readl(driver->icfgdrd_regs + ICFG_FSM_CTRL);
>>> +     val &= ~(DRD_HOST_MODE | DRD_DEVICE_MODE | ICFG_OFF_MODE);
>>> +     writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
>>> +
>>> +     return 0;
>>> +}
>>> +
>>> +static int ns2_drd_phy_poweron(struct phy *phy)
>>> +{
>>> +     struct ns2_phy_data *data = phy_get_drvdata(phy);
>>> +     struct ns2_phy_driver *driver = data->driver;
>>> +     u32 extcon_event = data->new_state;
>>> +     int ret;
>>> +     u32 val;
>>> +
>>> +     if (extcon_event == EVT_DEVICE) {
>>> +             writel(DRD_DEV_VAL, driver->icfgdrd_regs + ICFG_DRD_P0CTL);
>>> +
>>> +             val = readl(driver->icfgdrd_regs + ICFG_FSM_CTRL);
>>> +             val &= ~(DRD_HOST_MODE | ICFG_OFF_MODE);
>>> +             val |= DRD_DEVICE_MODE;
>>> +             writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
>>
>> Setting to DRD_DEVICE_MODE or DRD_HOST_MODE is done in connect_change. Why do
>> you want to do it here?
>
> Will remove it if not required for power management support. I would
> like this to be there now.
> Pls let me know.
>
>>> +
>>> +             val = readl(driver->idmdrd_rst_ctrl);
>>> +             val &= ~IDM_RST_BIT;
>>> +             writel(val, driver->idmdrd_rst_ctrl);
>>> +
>>> +             val = readl(driver->crmu_usb2_ctrl);
>>> +             val |= (AFE_CORERDY_VDDC | DRD_DEV_MODE);
>>> +             writel(val, driver->crmu_usb2_ctrl);
>>> +
>>> +             /* Bring PHY and PHY_PLL out of Reset */
>>> +             val = readl(driver->crmu_usb2_ctrl);
>>> +             val |= (PHY_PLL_RESETB | PHY_RESETB);
>>> +             writel(val, driver->crmu_usb2_ctrl);
>>> +
>>> +             ret = pll_lock_stat(ICFG_MISC_STAT, PHY_PLL_LOCK, driver);
>>> +             if (ret < 0) {
>>> +                     dev_err(&phy->dev, "Phy PLL lock failed\n");
>>> +                     goto err_shutdown;
>>> +             }
>>> +     } else {
>>> +             writel(DRD_HOST_VAL, driver->icfgdrd_regs + ICFG_DRD_P0CTL);
>>> +
>>> +             val = readl(driver->icfgdrd_regs + ICFG_FSM_CTRL);
>>> +             val &= ~(DRD_DEVICE_MODE | ICFG_OFF_MODE);
>>> +             val |= DRD_HOST_MODE;
>>> +             writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
>>> +
>>> +             val = readl(driver->crmu_usb2_ctrl);
>>> +             val |= AFE_CORERDY_VDDC;
>>> +             writel(val, driver->crmu_usb2_ctrl);
>>> +
>>> +             ret = pll_lock_stat(ICFG_MISC_STAT, PHY_PLL_LOCK, driver);
>>> +             if (ret < 0) {
>>> +                     dev_err(&phy->dev, "Phy PLL lock failed\n");
>>> +                     goto err_shutdown;
>>> +             }
>>> +
>>> +             val = readl(driver->idmdrd_rst_ctrl);
>>> +             val &= ~IDM_RST_BIT;
>>> +             writel(val, driver->idmdrd_rst_ctrl);
>>> +
>>> +             /* port over current Polarity */
>>> +             val = readl(driver->usb2h_strap_reg);
>>> +             val |= OHCI_OVRCUR_POL;
>>> +             writel(val, driver->usb2h_strap_reg);
>>> +     }
>>> +
>>> +     return 0;
>>> +
>>> +err_shutdown:
>>> +     ns2_drd_phy_shutdown(phy);
>>
>> This should be left for the consumer driver to handle.
>
> Ok.
>
>>> +     return ret;
>>> +}
>>> +
>>> +static void connect_change(struct ns2_phy_driver *driver)
>>> +{
>>> +     u32 extcon_event;
>>> +     u32 val;
>>> +
>>> +     extcon_event = driver->data->new_state;
>>> +     val = readl(driver->icfgdrd_regs + ICFG_FSM_CTRL);
>>> +
>>> +     switch (extcon_event) {
>>> +     case EVT_DEVICE:
>>> +             val &= ~(DRD_HOST_MODE | DRD_DEVICE_MODE);
>>> +             writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
>>> +
>>> +             val = (val & ~DRD_HOST_MODE) | DRD_DEVICE_MODE;
>>> +             writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
>>> +
>>> +             val = readl(driver->icfgdrd_regs + ICFG_DRD_P0CTL);
>>> +             val |= ICFG_DEV_BIT;
>>> +             writel(val, driver->icfgdrd_regs + ICFG_DRD_P0CTL);
>>> +             break;
>>> +
>>> +     case EVT_HOST:
>>> +             val &= ~(DRD_HOST_MODE | DRD_DEVICE_MODE);
>>> +             writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
>>> +
>>> +             val = (val & ~DRD_DEVICE_MODE) | DRD_HOST_MODE;
>>> +             writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
>>> +
>>> +             val = readl(driver->usb2h_strap_reg);
>>> +             val |= OHCI_OVRCUR_POL;
>>> +             writel(val, driver->usb2h_strap_reg);
>>> +
>>> +             val = readl(driver->icfgdrd_regs + ICFG_DRD_P0CTL);
>>> +             val &= ~ICFG_DEV_BIT;
>>> +             writel(val, driver->icfgdrd_regs + ICFG_DRD_P0CTL);
>>> +             break;
>>> +
>>> +     default:
>>> +             pr_err("Invalid extcon event\n");
>>> +             break;
>>> +     }
>>> +}
>>> +
>>> +static void extcon_work(struct work_struct *work)
>>> +{
>>> +     struct ns2_phy_driver *driver;
>>> +     int vbus;
>>> +     int id;
>>> +
>>> +     driver  = container_of(to_delayed_work(work),
>>> +                            struct ns2_phy_driver, wq_extcon);
>>> +
>>> +     id = gpiod_get_value_cansleep(driver->id_gpiod);
>>> +     vbus = gpiod_get_value_cansleep(driver->vbus_gpiod);
>>> +
>>> +     if (!id && vbus) { /* Host connected */
>>> +             extcon_set_cable_state_(driver->edev, EXTCON_USB_HOST, true);
>>
>> Why do you need all extcon_set_cable_state_ here?
>
> Based on the cable state, the UDC driver can do gagdet driver
> connect/disconnect,
> the way it is done now.
>
> Thanks,
> Ravi
>
>>
>> Thanks
>> Kishon