Re: [PATCH v4 3/6] phy: qcom-m31: Introduce qcom,m31 USB phy driver

From: Vinod Koul
Date: Fri Jul 14 2023 - 09:08:34 EST


On 12-07-23, 17:08, Varadarajan Narayanan wrote:
> Add the M31 USB2 phy driver.
>
> Signed-off-by: Varadarajan Narayanan <quic_varada@xxxxxxxxxxx>
> ---
> v4:
> Remove unused enum
> Error handling for devm_clk_get
> v1:
> Combine driver, makefile and kconfig into 1 patch
> Remove 'qscratch' region and its usage. The controller driver takes care
> of those settings
> Use compatible/data to handle ipq5332 init
> Drop the default case
> Get resources by index instead of name as there is only one resource
> Add clock
> Fix review comments in the driver
> ---
> drivers/phy/qualcomm/Kconfig | 11 ++
> drivers/phy/qualcomm/Makefile | 1 +
> drivers/phy/qualcomm/phy-qcom-m31.c | 256 ++++++++++++++++++++++++++++++++++++
> 3 files changed, 268 insertions(+)
> create mode 100644 drivers/phy/qualcomm/phy-qcom-m31.c
>
> diff --git a/drivers/phy/qualcomm/Kconfig b/drivers/phy/qualcomm/Kconfig
> index 97ca595..76be191 100644
> --- a/drivers/phy/qualcomm/Kconfig
> +++ b/drivers/phy/qualcomm/Kconfig
> @@ -197,3 +197,14 @@ config PHY_QCOM_SGMII_ETH
> help
> Enable this to support the internal SerDes/SGMII PHY on various
> Qualcomm chipsets.
> +
> +config PHY_QCOM_M31_USB

Sorted alphabetically please

> + tristate "Qualcomm M31 HS PHY driver support"
> + depends on (USB || USB_GADGET) && ARCH_QCOM
> + select USB_PHY
> + help
> + Enable this to support M31 HS PHY transceivers on Qualcomm chips
> + with DWC3 USB core. It handles PHY initialization, clock
> + management required after resetting the hardware and power
> + management. This driver is required even for peripheral only or
> + host only mode configurations.
> diff --git a/drivers/phy/qualcomm/Makefile b/drivers/phy/qualcomm/Makefile
> index b030858..0b5dd66 100644
> --- a/drivers/phy/qualcomm/Makefile
> +++ b/drivers/phy/qualcomm/Makefile
> @@ -22,3 +22,4 @@ obj-$(CONFIG_PHY_QCOM_USB_SS) += phy-qcom-usb-ss.o
> obj-$(CONFIG_PHY_QCOM_USB_SNPS_FEMTO_V2)+= phy-qcom-snps-femto-v2.o
> obj-$(CONFIG_PHY_QCOM_IPQ806X_USB) += phy-qcom-ipq806x-usb.o
> obj-$(CONFIG_PHY_QCOM_SGMII_ETH) += phy-qcom-sgmii-eth.o
> +obj-$(CONFIG_PHY_QCOM_M31_USB) += phy-qcom-m31.o

this one too

> diff --git a/drivers/phy/qualcomm/phy-qcom-m31.c b/drivers/phy/qualcomm/phy-qcom-m31.c
> new file mode 100644
> index 0000000..fd568ef
> --- /dev/null
> +++ b/drivers/phy/qualcomm/phy-qcom-m31.c
> @@ -0,0 +1,256 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2014-2016, 2020, The Linux Foundation. All rights reserved.
> + */

we are in 2023

> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/reset.h>
> +#include <linux/slab.h>
> +#include <linux/usb/of.h>
> +#include <linux/usb/phy.h>
> +
> +#define USB2PHY_PORT_UTMI_CTRL1 0x40
> +
> +#define USB2PHY_PORT_UTMI_CTRL2 0x44
> + #define UTMI_ULPI_SEL BIT(7)
> + #define UTMI_TEST_MUX_SEL BIT(6)
> +
> +#define HS_PHY_CTRL_REG 0x10
> + #define UTMI_OTG_VBUS_VALID BIT(20)
> + #define SW_SESSVLD_SEL BIT(28)
> +
> +#define USB_PHY_UTMI_CTRL0 0x3c
> +
> +#define USB_PHY_UTMI_CTRL5 0x50
> + #define POR_EN BIT(1)
> + #define ATERESET ~BIT(0)

??

> +
> +#define USB_PHY_HS_PHY_CTRL_COMMON0 0x54
> + #define COMMONONN BIT(7)
> + #define FSEL BIT(4)
> + #define RETENABLEN BIT(3)
> + #define FREQ_24MHZ (5 << 4)

Use GENMASK for these

> +
> +#define USB_PHY_HS_PHY_CTRL2 0x64
> + #define USB2_SUSPEND_N_SEL BIT(3)
> + #define USB2_SUSPEND_N BIT(2)
> + #define USB2_UTMI_CLK_EN BIT(1)
> +
> +#define USB_PHY_CFG0 0x94
> + #define UTMI_PHY_OVERRIDE_EN BIT(1)
> +
> +#define USB_PHY_REFCLK_CTRL 0xa0
> + #define CLKCORE BIT(1)
> +
> +#define USB2PHY_PORT_POWERDOWN 0xa4
> + #define POWER_UP BIT(0)
> + #define POWER_DOWN 0
> +
> +#define USB_PHY_FSEL_SEL 0xb8
> + #define FREQ_SEL BIT(0)
> +
> +#define USB2PHY_USB_PHY_M31_XCFGI_1 0xbc
> + #define USB2_0_TX_ENABLE BIT(2)
> +
> +#define USB2PHY_USB_PHY_M31_XCFGI_4 0xc8
> + #define HSTX_SLEW_RATE_565PS GENMASK(1, 0)
> + #define PLL_CHARGING_PUMP_CURRENT_35UA GENMASK(4, 3)
> + #define ODT_VALUE_38_02_OHM GENMASK(7, 6)
> +
> +#define USB2PHY_USB_PHY_M31_XCFGI_5 0xcc
> + #define ODT_VALUE_45_02_OHM BIT(2)
> + #define HSTX_PRE_EMPHASIS_LEVEL_0_55MA BIT(0)
> +
> +#define USB2PHY_USB_PHY_M31_XCFGI_11 0xe4
> + #define XCFG_COARSE_TUNE_NUM BIT(1)
> + #define XCFG_FINE_TUNE_NUM BIT(3)
> +
> +struct m31_phy_regs {
> + u32 off;
> + u32 val;
> + u32 delay;
> +};
> +
> +struct m31_priv_data {
> + bool ulpi_mode;
> + const struct m31_phy_regs *regs;
> +};
> +
> +#define M31_REG(__o, __v, __d) \
> + { .off = __o, .val = __v, .delay = __d }
> +
> +#define M31_REG_INVALID 0xffffffffu
> +
> +struct m31_phy_regs m31_ipq5332_regs[] = {
> + M31_REG(USB_PHY_CFG0, UTMI_PHY_OVERRIDE_EN, 0),
> + M31_REG(USB_PHY_UTMI_CTRL5, POR_EN, 15),
> + M31_REG(USB_PHY_FSEL_SEL, FREQ_SEL, 0),
> + M31_REG(USB_PHY_HS_PHY_CTRL_COMMON0,
> + COMMONONN | FREQ_24MHZ | RETENABLEN, 0),
> + M31_REG(USB_PHY_UTMI_CTRL5, POR_EN & ATERESET, 0),
> + M31_REG(USB_PHY_HS_PHY_CTRL2,
> + USB2_SUSPEND_N_SEL | USB2_SUSPEND_N | USB2_UTMI_CLK_EN, 0),
> + M31_REG(USB2PHY_USB_PHY_M31_XCFGI_11,
> + XCFG_COARSE_TUNE_NUM | XCFG_FINE_TUNE_NUM, 0),
> + M31_REG(USB2PHY_USB_PHY_M31_XCFGI_4,
> + HSTX_SLEW_RATE_565PS | PLL_CHARGING_PUMP_CURRENT_35UA |
> + ODT_VALUE_38_02_OHM, 0),
> + M31_REG(USB2PHY_USB_PHY_M31_XCFGI_1, USB2_0_TX_ENABLE, 0),
> + M31_REG(USB2PHY_USB_PHY_M31_XCFGI_5,
> + ODT_VALUE_45_02_OHM | HSTX_PRE_EMPHASIS_LEVEL_0_55MA, 4),
> + M31_REG(USB_PHY_UTMI_CTRL5, 0x0, 0),
> + M31_REG(USB_PHY_HS_PHY_CTRL2, USB2_SUSPEND_N | USB2_UTMI_CLK_EN, 0),
> + M31_REG(M31_REG_INVALID, 0, 0),
> +};
> +
> +struct m31usb_phy {
> + struct usb_phy phy;
> + void __iomem *base;
> + const struct m31_phy_regs *regs;
> +
> + struct clk *cfg_ahb_clk;
> + struct reset_control *phy_reset;
> +
> + bool cable_connected;
> + bool suspended;
> + bool ulpi_mode;
> +};
> +
> +static void m31usb_phy_enable_clock(struct m31usb_phy *qphy)
> +{
> + const struct m31_phy_regs *regs = qphy->regs;
> +
> + for (; regs->off != M31_REG_INVALID; regs++) {

why have last entry as invalid and check that, this is an array so you
can use ARRAY_SIZE to define the count of regs

> + writel(regs->val, qphy->base + regs->off);
> + if (regs->delay)
> + udelay(regs->delay);
> + }
> +}
> +
> +static int m31usb_phy_init(struct usb_phy *phy)
> +{
> + int ret;
> + struct m31usb_phy *qphy = container_of(phy, struct m31usb_phy, phy);
> +
> + ret = clk_prepare_enable(qphy->cfg_ahb_clk);
> + if (ret) {
> + dev_err(phy->dev, "failed to enable cfg ahb clock, %d\n", ret);
> + return ret;
> + }
> +
> + /* Perform phy reset */
> + reset_control_assert(qphy->phy_reset);
> + udelay(5);
> + reset_control_deassert(qphy->phy_reset);
> +
> + /* configure for ULPI mode if requested */
> + if (qphy->ulpi_mode)
> + writel(0x0, qphy->base + USB2PHY_PORT_UTMI_CTRL2);
> +
> + /* Enable the PHY */
> + writel(POWER_UP, qphy->base + USB2PHY_PORT_POWERDOWN);
> +
> + /* Make sure above write completed */
> + wmb();
> +
> + /* Turn on phy ref clock */
> + m31usb_phy_enable_clock(qphy);
> +
> + return 0;
> +}
> +
> +static void m31usb_phy_shutdown(struct usb_phy *phy)
> +{
> + struct m31usb_phy *qphy = container_of(phy, struct m31usb_phy, phy);
> +
> + /* Disable the PHY */
> + writel_relaxed(POWER_DOWN, qphy->base + USB2PHY_PORT_POWERDOWN);
> + /* Make sure above write completed */
> + wmb();
> +
> + clk_disable_unprepare(qphy->cfg_ahb_clk);
> +}
> +
> +static int m31usb_phy_probe(struct platform_device *pdev)
> +{
> + const struct m31_priv_data *data;
> + struct device *dev = &pdev->dev;
> + struct m31usb_phy *qphy;
> + int ret;
> +
> + qphy = devm_kzalloc(dev, sizeof(*qphy), GFP_KERNEL);
> + if (!qphy)
> + return -ENOMEM;
> +
> + qphy->phy.dev = dev;
> +
> + qphy->base = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(qphy->base))
> + return PTR_ERR(qphy->base);
> +
> + qphy->phy_reset = devm_reset_control_get_exclusive_by_index(dev, 0);
> + if (IS_ERR(qphy->phy_reset))
> + return PTR_ERR(qphy->phy_reset);
> +
> + qphy->cfg_ahb_clk = devm_clk_get(dev, "cfg_ahb");
> + if (IS_ERR(qphy->cfg_ahb_clk)) {
> + ret = PTR_ERR(qphy->cfg_ahb_clk);
> + dev_err(dev, "failed to get cfg_ahb clock, %d\n", ret);
> + return ret;
> + }
> +
> + platform_set_drvdata(pdev, qphy);
> +
> + data = of_device_get_match_data(dev);
> + qphy->regs = data->regs;
> + qphy->ulpi_mode = data->ulpi_mode;
> +
> + qphy->phy.label = "m31-usb-phy";
> + qphy->phy.init = m31usb_phy_init;
> + qphy->phy.shutdown = m31usb_phy_shutdown;
> + qphy->phy.type = USB_PHY_TYPE_USB2;
> +
> + ret = usb_add_phy_dev(&qphy->phy);

why usb and not devm_phy_create()? It should be generic phy here

--
~Vinod