Re: [PATCH v3 2/2] phy: bcm-sr-pcie: Add Stingray PCIe PHY driver

[Kishon Vijay Abraham I]

Hi,

On Wednesday 04 July 2018 11:52 PM, Ray Jui wrote:
> Add Stingray PCIe PHY driver for both PAXB and PAXC root complex
> 
> Signed-off-by: Ray Jui <ray.jui@xxxxxxxxxxxx>
> ---
>  drivers/phy/broadcom/Kconfig           |  10 +
>  drivers/phy/broadcom/Makefile          |   2 +
>  drivers/phy/broadcom/phy-bcm-sr-pcie.c | 327 +++++++++++++++++++++++++++++++++
>  3 files changed, 339 insertions(+)
>  create mode 100644 drivers/phy/broadcom/phy-bcm-sr-pcie.c
> 
> diff --git a/drivers/phy/broadcom/Kconfig b/drivers/phy/broadcom/Kconfig
> index 97d27b0d5..8786a96 100644
> --- a/drivers/phy/broadcom/Kconfig
> +++ b/drivers/phy/broadcom/Kconfig
> @@ -80,3 +80,13 @@ config PHY_BRCM_USB
>  	  This driver is required by the USB XHCI, EHCI and OHCI
>  	  drivers.
>  	  If unsure, say N.
> +
> +config PHY_BCM_SR_PCIE
> +	tristate "Broadcom Stingray PCIe PHY driver"
> +	depends on OF && (ARCH_BCM_IPROC || COMPILE_TEST)
> +	select GENERIC_PHY
> +	select MFD_SYSCON
> +	default ARCH_BCM_IPROC
> +	help
> +	  Enable this to support the Broadcom Stingray PCIe PHY
> +	  If unsure, say N.
> diff --git a/drivers/phy/broadcom/Makefile b/drivers/phy/broadcom/Makefile
> index 13e000c..0f60184 100644
> --- a/drivers/phy/broadcom/Makefile
> +++ b/drivers/phy/broadcom/Makefile
> @@ -9,3 +9,5 @@ obj-$(CONFIG_PHY_BRCM_SATA)		+= phy-brcm-sata.o
>  obj-$(CONFIG_PHY_BRCM_USB)		+= phy-brcm-usb-dvr.o
>  
>  phy-brcm-usb-dvr-objs := phy-brcm-usb.o phy-brcm-usb-init.o
> +
> +obj-$(CONFIG_PHY_BCM_SR_PCIE)		+= phy-bcm-sr-pcie.o
> diff --git a/drivers/phy/broadcom/phy-bcm-sr-pcie.c b/drivers/phy/broadcom/phy-bcm-sr-pcie.c
> new file mode 100644
> index 0000000..ff15dae
> --- /dev/null
> +++ b/drivers/phy/broadcom/phy-bcm-sr-pcie.c
> @@ -0,0 +1,327 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2016-2018 Broadcom
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/of.h>
> +#include <linux/phy/phy.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +/* we have up to 8 PAXB based RC. The 9th one is always PAXC */
> +#define SR_NR_PCIE_PHYS               9
> +#define SR_PAXC_PHY_IDX               (SR_NR_PCIE_PHYS - 1)
> +
> +#define PCIE_PIPEMUX_CFG_OFFSET       0x10c
> +#define PCIE_PIPEMUX_SELECT_STRAP     0xf
> +
> +#define CDRU_STRAP_DATA_LSW_OFFSET    0x5c
> +#define PCIE_PIPEMUX_SHIFT            19
> +#define PCIE_PIPEMUX_MASK             0xf
> +
> +#define MHB_MEM_PW_PAXC_OFFSET        0x1c0
> +#define MHB_PWR_ARR_POWERON           0x8
> +#define MHB_PWR_ARR_POWEROK           0x4
> +#define MHB_PWR_POWERON               0x2
> +#define MHB_PWR_POWEROK               0x1
> +#define MHB_PWR_STATUS_MASK           (MHB_PWR_ARR_POWERON | \
> +				       MHB_PWR_ARR_POWEROK | \
> +				       MHB_PWR_POWERON | \
> +				       MHB_PWR_POWEROK)
> +
> +struct sr_pcie_phy_core;
> +
> +/**
> + * struct sr_pcie_phy - Stingray PCIe PHY
> + *
> + * @core: pointer to the Stingray PCIe PHY core control
> + * @index: PHY index
> + * @phy: pointer to the kernel PHY device
> + */
> +struct sr_pcie_phy {
> +	struct sr_pcie_phy_core *core;
> +	unsigned int index;
> +	struct phy *phy;
> +};
> +
> +/**
> + * struct sr_pcie_phy_core - Stingray PCIe PHY core control
> + *
> + * @dev: pointer to device
> + * @base: base register of PCIe SS
> + * @cdru: regmap to the CDRU device
> + * @mhb: regmap to the MHB device
> + * @pipemux: pipemuex strap
> + * @phys: array of PCIe PHYs
> + */
> +struct sr_pcie_phy_core {
> +	struct device *dev;
> +	void __iomem *base;
> +	struct regmap *cdru;
> +	struct regmap *mhb;
> +	u32 pipemux;
> +	struct sr_pcie_phy phys[SR_NR_PCIE_PHYS];
> +};
> +
> +/*
> + * PCIe PIPEMUX lookup table
> + *
> + * Each array index represents a PIPEMUX strap setting
> + * The array element represents a bitmap where a set bit means the PCIe
> + * core and associated serdes has been enabled as RC and is available for use
> + */
> +static const u8 pipemux_table[] = {
> +	/* PIPEMUX = 0, EP 1x16 */
> +	0x00,
> +	/* PIPEMUX = 1, EP 2x8 */
> +	0x00,
> +	/* PIPEMUX = 2, EP 4x4 */
> +	0x00,
> +	/* PIPEMUX = 3, RC 2x8, cores 0, 7 */
> +	0x81,
> +	/* PIPEMUX = 4, RC 4x4, cores 0, 1, 6, 7 */
> +	0xc3,
> +	/* PIPEMUX = 5, RC 8x2, all 8 cores */
> +	0xff,
> +	/* PIPEMUX = 6, RC 3x4 + 2x2, cores 0, 2, 3, 6, 7 */
> +	0xcd,
> +	/* PIPEMUX = 7, RC 1x4 + 6x2, cores 0, 2, 3, 4, 5, 6, 7 */
> +	0xfd,
> +	/* PIPEMUX = 8, EP 1x8 + RC 4x2, cores 4, 5, 6, 7 */
> +	0xf0,
> +	/* PIPEMUX = 9, EP 1x8 + RC 2x4, cores 6, 7 */
> +	0xc0,
> +	/* PIPEMUX = 10, EP 2x4 + RC 2x4, cores 1, 6 */
> +	0x42,
> +	/* PIPEMUX = 11, EP 2x4 + RC 4x2, cores 2, 3, 4, 5 */
> +	0x3c,
> +	/* PIPEMUX = 12, EP 1x4 + RC 6x2, cores 2, 3, 4, 5, 6, 7 */
> +	0xfc,
> +	/* PIPEMUX = 13, RC 2x4 + RC 1x4 + 2x2, cores 2, 3, 6 */
> +	0x4c,
> +};

Please use mux framework for this. (drivers/mux/mmio.c)
> +
> +/*
> + * Return true if the strap setting is valid
> + */
> +static bool pipemux_strap_is_valid(u32 pipemux)
> +{
> +	return !!(pipemux < ARRAY_SIZE(pipemux_table));
> +}
> +
> +/*
> + * Read the PCIe PIPEMUX from strap
> + */
> +static u32 pipemux_strap_read(struct sr_pcie_phy_core *core)
> +{
> +	u32 pipemux;
> +
> +	/*
> +	 * Read PIPEMUX configuration register to determine the pipemux setting
> +	 *
> +	 * In the case when the value indicates using HW strap, fall back to
> +	 * use HW strap
> +	 */
> +	pipemux = readl(core->base + PCIE_PIPEMUX_CFG_OFFSET);
> +	pipemux &= PCIE_PIPEMUX_MASK;
> +	if (pipemux == PCIE_PIPEMUX_SELECT_STRAP) {
> +		regmap_read(core->cdru, CDRU_STRAP_DATA_LSW_OFFSET, &pipemux);
> +		pipemux >>= PCIE_PIPEMUX_SHIFT;
> +		pipemux &= PCIE_PIPEMUX_MASK;
> +	}
> +
> +	return pipemux;
> +}
> +
> +/*
> + * Given a PIPEMUX strap and PCIe core index, this function returns true if the
> + * PCIe core needs to be enabled
> + */
> +static bool pcie_core_is_for_rc(struct sr_pcie_phy *phy)
> +{
> +	struct sr_pcie_phy_core *core = phy->core;
> +	unsigned int core_idx = phy->index;
> +
> +	return !!((pipemux_table[core->pipemux] >> core_idx) & 0x1);
> +}
> +
> +static int sr_pcie_phy_init(struct phy *p)
> +{
> +	struct sr_pcie_phy *phy = phy_get_drvdata(p);
> +
> +	/*
> +	 * Check whether this PHY is for root complex or not. If yes, return
> +	 * zero so the host driver can proceed to enumeration. If not, return
> +	 * an error and that will force the host driver to bail out
> +	 */
> +	if (pcie_core_is_for_rc(phy))
> +		return 0;
> +	else

This else can be removed.
> +		return -ENODEV;
> +}
> +
> +static int sr_paxc_phy_init(struct phy *p)
> +{
> +	struct sr_pcie_phy *phy = phy_get_drvdata(p);
> +	struct sr_pcie_phy_core *core = phy->core;
> +	unsigned int core_idx = phy->index;
> +	u32 val;
> +
> +	if (core_idx != SR_PAXC_PHY_IDX)
> +		return -EINVAL;
> +
> +	regmap_read(core->mhb, MHB_MEM_PW_PAXC_OFFSET, &val);
> +	if ((val & MHB_PWR_STATUS_MASK) != MHB_PWR_STATUS_MASK) {
> +		dev_err(core->dev, "PAXC is not powered up\n");
> +		return -ENODEV;
> +	}
> +
> +	return 0;
> +}
> +
> +static int sr_pcie_phy_exit(struct phy *p)
> +{
> +	/* dummy function to allow host driver to proceed */
> +	return 0;
> +}
> +
> +static int sr_pcie_phy_power_on(struct phy *p)
> +{
> +	/* dummy function to allow host driver to proceed */
> +	return 0;
> +}
> +
> +static int sr_pcie_phy_power_off(struct phy *p)
> +{
> +	/* dummy function to allow host to proceed */
> +	return 0;
> +}

dummy functions are not required.
> +
> +static const struct phy_ops sr_pcie_phy_ops = {
> +	.init = sr_pcie_phy_init,
> +	.exit = sr_pcie_phy_exit,
> +	.power_on = sr_pcie_phy_power_on,
> +	.power_off = sr_pcie_phy_power_off,
> +};
> +
> +static const struct phy_ops sr_paxc_phy_ops = {
> +	.init = sr_paxc_phy_init,
> +	.exit = sr_pcie_phy_exit,
> +	.power_on = sr_pcie_phy_power_on,
> +	.power_off = sr_pcie_phy_power_off,
> +};

phy_ops should have .owner.

Thanks
Kishon