Re: [PATCH v3 06/10] phy: qcom: Add M31 based eUSB2 PHY driver

From: Dmitry Baryshkov
Date: Wed Mar 26 2025 - 10:34:21 EST


On Mon, Mar 24, 2025 at 01:18:34PM -0700, Melody Olvera wrote:
> From: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
>
> SM8750 utilizes an eUSB2 PHY from M31. Add the initialization
> sequences to bring it out of reset and into an operational state. This
> differs to the M31 USB driver, in that the M31 eUSB2 driver will
> require a connection to an eUSB2 repeater. This PHY driver will handle
> the initialization of the associated eUSB2 repeater when required.
>
> Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
> Signed-off-by: Melody Olvera <quic_molvera@xxxxxxxxxxx>
> ---
> drivers/phy/qualcomm/Kconfig | 10 +
> drivers/phy/qualcomm/Makefile | 1 +
> drivers/phy/qualcomm/phy-qcom-m31-eusb2.c | 297 ++++++++++++++++++++++++++++++
> 3 files changed, 308 insertions(+)
>
> diff --git a/drivers/phy/qualcomm/phy-qcom-m31-eusb2.c b/drivers/phy/qualcomm/phy-qcom-m31-eusb2.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..b18aab968122683e2e87287a4b570321d376870a
> --- /dev/null
> +++ b/drivers/phy/qualcomm/phy-qcom-m31-eusb2.c
> @@ -0,0 +1,297 @@
> +// SPDX-License-Identifier: GPL-2.0+

GPL-2.0-only

> +/*
> + * Copyright (c) 2024-2025 Qualcomm Innovation Center, Inc. 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.h>
> +#include <linux/phy/phy.h>
> +#include <linux/platform_device.h>
> +#include <linux/reset.h>
> +#include <linux/slab.h>
> +
> +#include <linux/regulator/consumer.h>
> +
> +#define USB_PHY_UTMI_CTRL0 (0x3c)
> +
> +#define USB_PHY_UTMI_CTRL5 (0x50)
> +
> +#define USB_PHY_HS_PHY_CTRL_COMMON0 (0x54)
> +#define FSEL GENMASK(6, 4)
> +#define FSEL_38_4_MHZ_VAL (0x6)
> +
> +#define USB_PHY_HS_PHY_CTRL2 (0x64)
> +
> +#define USB_PHY_CFG0 (0x94)
> +#define USB_PHY_CFG1 (0x154)
> +
> +#define USB_PHY_FSEL_SEL (0xb8)
> +
> +#define USB_PHY_XCFGI_39_32 (0x16c)
> +#define USB_PHY_XCFGI_71_64 (0x17c)
> +#define USB_PHY_XCFGI_31_24 (0x168)
> +#define USB_PHY_XCFGI_7_0 (0x15c)
> +
> +#define M31_EUSB_PHY_INIT_CFG(o, b, v) \
> +{ \
> + .off = o, \
> + .mask = b, \
> + .val = v, \
> +}
> +
> +struct m31_phy_tbl_entry {
> + u32 off;
> + u32 mask;
> + u32 val;
> +};
> +
> +struct m31_eusb2_priv_data {
> + const struct m31_phy_tbl_entry *setup_seq;
> + unsigned int setup_seq_nregs;
> + const struct m31_phy_tbl_entry *override_seq;
> + unsigned int override_seq_nregs;
> + const struct m31_phy_tbl_entry *reset_seq;
> + unsigned int reset_seq_nregs;
> + unsigned int fsel;
> +};
> +
> +static const struct m31_phy_tbl_entry m31_eusb2_setup_tbl[] = {
> + M31_EUSB_PHY_INIT_CFG(USB_PHY_CFG0, BIT(1), 1),
> + M31_EUSB_PHY_INIT_CFG(USB_PHY_UTMI_CTRL5, BIT(1), 1),
> + M31_EUSB_PHY_INIT_CFG(USB_PHY_CFG1, BIT(0), 1),
> + M31_EUSB_PHY_INIT_CFG(USB_PHY_FSEL_SEL, BIT(0), 1),

I suppose, we can not expect to have #defines for all used bitfields?

> +};
> +

[...]

> +
> +static const struct phy_ops m31eusb2_phy_gen_ops = {
> + .init = m31eusb2_phy_init,
> + .exit = m31eusb2_phy_exit,

I think, you have a missing .set_mode callback here.

> + .owner = THIS_MODULE,
> +};
> +
> +static int m31eusb2_phy_probe(struct platform_device *pdev)
> +{
> + struct phy_provider *phy_provider;
> + const struct m31_eusb2_priv_data *data;
> + struct device *dev = &pdev->dev;
> + struct m31eusb2_phy *phy;
> + int ret;
> +
> + phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
> + if (!phy)
> + return -ENOMEM;
> +
> + data = of_device_get_match_data(dev);

device_get_match_data()

> + if (IS_ERR(data))
> + return -EINVAL;
> + phy->data = data;
> +

--
With best wishes
Dmitry