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Message-ID: <CAEHZuqMXqq=xue51Y6yHZBN9ZWaB3j9sXoy6n-eTWB+M0jHuhA@mail.gmail.com>
Date: Fri, 27 Jan 2017 18:03:33 +0530
From: Raviteja Garimella <raviteja.garimella@...adcom.com>
To: Kishon Vijay Abraham I <kishon@...com>
Cc: Rob Herring <robh+dt@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Ray Jui <rjui@...adcom.com>,
Scott Branden <sbranden@...adcom.com>,
Jon Mason <jonmason@...adcom.com>,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will.deacon@....com>, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org,
BCM Kernel Feedback <bcm-kernel-feedback-list@...adcom.com>,
linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v2 2/3] Broadcom USB DRD Phy driver for Northstar2
Hi Kishon,
On Thu, Jan 26, 2017 at 9:13 PM, Kishon Vijay Abraham I <kishon@...com> wrote:
> Hi,
>
> On Wednesday 18 January 2017 05:50 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@...adcom.com>
>> ---
>> drivers/phy/Kconfig | 13 +
>> drivers/phy/Makefile | 1 +
>> drivers/phy/phy-bcm-ns2-usbdrd.c | 588 +++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 602 insertions(+)
>> create mode 100644 drivers/phy/phy-bcm-ns2-usbdrd.c
>>
>> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
>> index e8eb7f2..1b3de42 100644
>> --- a/drivers/phy/Kconfig
>> +++ b/drivers/phy/Kconfig
>> @@ -463,6 +463,19 @@ 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 65eb2f4..cfbdd9a 100644
>> --- a/drivers/phy/Makefile
>> +++ b/drivers/phy/Makefile
>> @@ -56,6 +56,7 @@ 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..e9478d1
>> --- /dev/null
>> +++ b/drivers/phy/phy-bcm-ns2-usbdrd.c
>> @@ -0,0 +1,588 @@
>> +/*
>> + * Copyright (C) 2016 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 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 EVT_IDLE 2
>> +
>> +#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
>> +#define PHY_WQ_DELAY msecs_to_jiffies(600)
>> +
>> +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;
>> + spinlock_t lock; /* spin lock for phy driver */
>> + bool host_mode;
>> + struct ns2_phy_data *data;
>> + struct extcon_specific_cable_nb extcon_dev;
>> + struct extcon_specific_cable_nb extcon_host;
>> + struct notifier_block host_nb;
>> + struct notifier_block dev_nb;
>> + struct delayed_work conn_work;
>> + struct extcon_dev *edev;
>> + 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;
>> + bool poweron;
>> +};
>> +
>> +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;
>> + unsigned long flags;
>> + u32 val;
>> +
>> + spin_lock_irqsave(&driver->lock, flags);
>
> Is this a multi-phy phy driver? if not remove the spinlock used in this driver.
>> +
>> + 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);
>> +
>> + spin_unlock_irqrestore(&driver->lock, flags);
>> + 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;
>> + unsigned long flags;
>> + u32 val;
>> +
>> + spin_lock_irqsave(&driver->lock, flags);
>> + if (!data->poweron)
>> + goto exit;
>> +
>> + val = readl(driver->crmu_usb2_ctrl);
>> + val &= ~AFE_CORERDY_VDDC;
>> + writel(val, driver->crmu_usb2_ctrl);
>> +
>> + driver->host_mode = 0;
>> + 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);
>> +
>> + data->poweron = 0;
>> +exit:
>> + spin_unlock_irqrestore(&driver->lock, flags);
>> + 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;
>> + unsigned long flags;
>> + int ret;
>> + u32 val;
>> +
>> + spin_lock_irqsave(&driver->lock, flags);
>> + if (extcon_event == EVT_DEVICE) {
>> + if (data->poweron)
>> + goto exit;
>> +
>> + 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);
>> +
>> + 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 {
>> + if (data->poweron && driver->host_mode)
>> + goto exit;
>> +
>> + 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);
>> +
>> + driver->host_mode = 1;
>> + }
>> +
>> + data->poweron = 1;
>
> phy-core performs the reference counting. This should be not needed here.
Yes, verified it is not needed. Will make this change in next patch version.
>> +exit:
>> + spin_unlock_irqrestore(&driver->lock, flags);
>> + return 0;
>> +
>> +err_shutdown:
>> + data->poweron = 1;
>> + spin_unlock_irqrestore(&driver->lock, flags);
>> + ns2_drd_phy_shutdown(phy);
>> + return ret;
>> +}
>> +
>> +static void connect_work(struct work_struct *work)
>> +{
>> + struct ns2_phy_driver *driver;
>> + struct ns2_phy_data *data;
>> + u32 extcon_event;
>> +
>> + driver = container_of(to_delayed_work(work),
>> + struct ns2_phy_driver, conn_work);
>> + data = driver->data;
>> + extcon_event = data->new_state;
>> +
>> + if (extcon_event == EVT_DEVICE || extcon_event == EVT_HOST) {
>> + ns2_drd_phy_init(data->phy);
>> + ns2_drd_phy_poweron(data->phy);
>
> Ah, there are two ways in which you can phy_init/poweron can be done. That's
> why you used spinlock.
Correct.
>
> If it's based on what cable is connected, why do you even need phy ops? I think
> the phy ops should be split so that the init/poweron should be done in phy ops
> and host/device mode specific config should be done in extcon event.
Phy ops is needed in case any controller calls phy poweron/init/exit
during probe
and power management. The extcon here handles it during runtime, say once after
boot, unplug the device cable and use the host cable. In such cases,
it is required that
we shutdown and init the phy once again.
Even now the driver has the work split between init and poweron (in
the phy ops).
But powen on sequence for either mode is required during change of
states (i.e., as per
extcon event).
Thanks,
Ravi
>
> Thanks
> Kishon
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