Re: [PATCH v3 3/6] phy: qcom-m31: Introduce qcom,m31 USB phy driver

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 11/07/2023 10:51, Varadarajan Narayanan wrote:
> Add the M31 USB2 phy driver.
> 
> Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
> ---
> 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
> +	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
> diff --git a/drivers/phy/qualcomm/phy-qcom-m31.c b/drivers/phy/qualcomm/phy-qcom-m31.c
> new file mode 100644
> index 0000000..8700728
> --- /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.
> + */
> +
> +#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>
> +
> +enum clk_reset_action {
> +	CLK_RESET_DEASSERT	= 0,
> +	CLK_RESET_ASSERT	= 1
> +};

Drop entire enum. I don't see it being used.

...

> +
> +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");

How do you handle errors? I don't see it.

> +	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);
> +
> +	return ret;
> +}
> +
> +static void m31usb_phy_remove(struct platform_device *pdev)
> +{
> +	struct m31usb_phy *qphy = platform_get_drvdata(pdev);
> +
> +	usb_remove_phy(&qphy->phy);
> +}
> +
> +struct m31_priv_data m31_ipq5332_data = {

static const

> +	.ulpi_mode = false,
> +	.regs = m31_ipq5332_regs,
> +};


Best regards,
Krzysztof