Re: [PATCH V2] net: phy: tja11xx: Add TJA11xx PHY driver

[Heiner Kallweit <hkallweit1@gmail.com>]

On 14.12.2018 17:11, Marek Vasut wrote:
> Add driver for the NXP TJA1100 and TJA1101 PHYs. These PHYs are special
> BroadRReach 100BaseT1 PHYs used in automotive.
> 
> Signed-off-by: Marek Vasut <marex@denx.de>
> ---
> V2: - Use phy_modify(), phy_{set,clear}_bits()
>     - Drop enable argument of tja11xx_enable_link_control()
>     - Use PHY_BASIC_T1_FEATURES and dont modify supported/advertised
>       features in config_init callback
>     - Use genphy_soft_reset() instead of opencoding the reset sequence.
>     - Drop the aneg parts, since the PHY datasheet claims it does not
>       support aneg
> ---
>  drivers/net/phy/Kconfig       |   5 +
>  drivers/net/phy/Makefile      |   1 +
>  drivers/net/phy/nxp-tja11xx.c | 312 ++++++++++++++++++++++++++++++++++
>  3 files changed, 318 insertions(+)
>  create mode 100644 drivers/net/phy/nxp-tja11xx.c
> 
> diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
> index 3d187cd50eb0..ad7420c95fa6 100644
> --- a/drivers/net/phy/Kconfig
> +++ b/drivers/net/phy/Kconfig
> @@ -389,6 +389,11 @@ config NATIONAL_PHY
>  	---help---
>  	  Currently supports the DP83865 PHY.
>  
> +config NXP_TJA11XX_PHY
> +	tristate "NXP TJA11xx PHYs support"
> +	---help---
> +	  Currently supports the NXP TJA1100 and TJA1101 PHY.
> +
>  config QSEMI_PHY
>  	tristate "Quality Semiconductor PHYs"
>  	---help---
> diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
> index 5805c0b7d60e..023e5db8c7cc 100644
> --- a/drivers/net/phy/Makefile
> +++ b/drivers/net/phy/Makefile
> @@ -76,6 +76,7 @@ obj-$(CONFIG_MICROCHIP_PHY)	+= microchip.o
>  obj-$(CONFIG_MICROCHIP_T1_PHY)	+= microchip_t1.o
>  obj-$(CONFIG_MICROSEMI_PHY)	+= mscc.o
>  obj-$(CONFIG_NATIONAL_PHY)	+= national.o
> +obj-$(CONFIG_NXP_TJA11XX_PHY)	+= nxp-tja11xx.o
>  obj-$(CONFIG_QSEMI_PHY)		+= qsemi.o
>  obj-$(CONFIG_REALTEK_PHY)	+= realtek.o
>  obj-$(CONFIG_RENESAS_PHY)	+= uPD60620.o
> diff --git a/drivers/net/phy/nxp-tja11xx.c b/drivers/net/phy/nxp-tja11xx.c
> new file mode 100644
> index 000000000000..8a3f4f15d215
> --- /dev/null
> +++ b/drivers/net/phy/nxp-tja11xx.c
> @@ -0,0 +1,312 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* NXP TJA1100 BroadRReach PHY driver
> + *
> + * Copyright (C) 2018 Marek Vasut <marex@denx.de>
> + */
> +#include <linux/delay.h>
> +#include <linux/ethtool.h>
> +#include <linux/kernel.h>
> +#include <linux/mii.h>
> +#include <linux/module.h>
> +#include <linux/phy.h>
> +
> +#define PHY_ID_MASK			0xfffffff0
> +#define PHY_ID_TJA1100			0x0180dc40
> +#define PHY_ID_TJA1101			0x0180dd00
> +
> +#define MII_ECTRL			17
> +#define MII_ECTRL_LINK_CONTROL		BIT(15)
> +#define MII_ECTRL_POWER_MODE_MASK	GENMASK(14, 11)
> +#define MII_ECTRL_POWER_MODE_NO_CHANGE	(0x0 << 11)
> +#define MII_ECTRL_POWER_MODE_NORMAL	(0x3 << 11)
> +#define MII_ECTRL_POWER_MODE_STANDBY	(0xc << 11)
> +#define MII_ECTRL_CONFIG_EN		BIT(2)
> +#define MII_ECTRL_WAKE_REQUEST		BIT(0)
> +
> +#define MII_CFG1			18
> +#define MII_CFG1_AUTO_OP		BIT(14)
> +#define MII_CFG1_SLEEP_CONFIRM		BIT(6)
> +#define MII_CFG1_LED_MODE_MASK		GENMASK(5, 4)
> +#define MII_CFG1_LED_MODE_LINKUP	0
> +#define MII_CFG1_LED_ENABLE		BIT(3)
> +
> +#define MII_CFG2			19
> +#define MII_CFG2_SLEEP_REQUEST_TO	GENMASK(1, 0)
> +#define MII_CFG2_SLEEP_REQUEST_TO_16MS	0x3
> +
> +#define MII_INTSRC			21
> +
> +#define MII_COMMSTAT			23
> +#define MII_COMMSTAT_LINK_UP		BIT(15)
> +
> +#define MII_GENSTAT			24
> +#define MII_GENSTAT_PLL_LOCKED		BIT(14)
> +
> +#define MII_COMMCFG			27
> +#define MII_COMMCFG_AUTO_OP		BIT(15)
> +
> +struct tja11xx_phy_stats {
> +	const char	*string;
> +	u8		reg;
> +	u8		off;
> +	u16		mask;
> +};
> +
> +static struct tja11xx_phy_stats tja11xx_hw_stats[] = {
> +	{ "phy_symbol_error_count", 20, 0, 0xffff },
> +	{ "phy_overtemp_error", 21, 1, BIT(1) },
> +	{ "phy_undervolt_error", 21, 3, BIT(3) },
> +	{ "phy_polarity_detect", 25, 6, BIT(6) },
> +	{ "phy_open_detect", 25, 7, BIT(7) },
> +	{ "phy_short_detect", 25, 8, BIT(8) },
> +	{ "phy_rem_rcvr_count", 26, 0, 0xff },
> +	{ "phy_loc_rcvr_count", 26, 8, 0xff },
> +};
> +
> +static int tja11xx_check(struct phy_device *phydev, u8 reg, u16 clr, u16 set)

Based on how you use "clr" it may be better to call this parameter "mask".

> +{
> +	int i, ret;
> +
> +	for (i = 0; i < 200; i++) {
> +		ret = phy_read(phydev, reg);
> +		if (ret < 0)
> +			return ret;
> +
> +		if ((ret & clr) == set)
> +			return 0;
> +
> +		usleep_range(100, 150);
> +	}
> +
> +	return -ETIMEDOUT;
> +}
> +
> +static int phy_modify_check(struct phy_device *phydev, u8 reg,
> +			     u16 clr, u16 set)

Same here

> +{
> +	int ret;
> +
> +	ret = phy_modify(phydev, reg, clr, set);
> +	if (ret)
> +		return ret;
> +
> +	return tja11xx_check(phydev, reg, clr, set);
> +}
> +
> +static int tja11xx_enable_reg_write(struct phy_device *phydev)
> +{
> +	return phy_set_bits(phydev, MII_ECTRL, MII_ECTRL_CONFIG_EN);
> +}
> +
> +static int tja11xx_enable_link_control(struct phy_device *phydev)
> +{
> +	return phy_set_bits(phydev, MII_ECTRL, MII_ECTRL_LINK_CONTROL);
> +}
> +
> +static int tja11xx_wakeup(struct phy_device *phydev)
> +{
> +	int ret;
> +
> +	ret = phy_read(phydev, MII_ECTRL);
> +	if (ret < 0)
> +		return ret;
> +
> +	switch (ret & MII_ECTRL_POWER_MODE_MASK) {
> +	case MII_ECTRL_POWER_MODE_NO_CHANGE:
> +		break;
> +	case MII_ECTRL_POWER_MODE_NORMAL:
> +		ret = phy_set_bits(phydev, MII_ECTRL, MII_ECTRL_WAKE_REQUEST);
> +		if (ret)
> +			return ret;
> +
> +		ret = phy_clear_bits(phydev, MII_ECTRL, MII_ECTRL_WAKE_REQUEST);
> +		if (ret)
> +			return ret;
> +		break;
> +	case MII_ECTRL_POWER_MODE_STANDBY:
> +		ret = phy_modify_check(phydev, MII_ECTRL,
> +					MII_ECTRL_POWER_MODE_MASK,
> +					MII_ECTRL_POWER_MODE_STANDBY);
> +		if (ret)
> +			return ret;
> +
> +		ret = phy_modify(phydev, MII_ECTRL, MII_ECTRL_POWER_MODE_MASK,
> +				 MII_ECTRL_POWER_MODE_NORMAL);
> +		if (ret)
> +			return ret;
> +
> +		ret = phy_modify_check(phydev, MII_GENSTAT,
> +					MII_GENSTAT_PLL_LOCKED,
> +					MII_GENSTAT_PLL_LOCKED);
> +		if (ret)
> +			return ret;
> +
> +		return tja11xx_enable_link_control(phydev);
> +	default:
> +		break;
> +	}
> +
> +	return 0;
> +}
> +
> +static int tja11xx_soft_reset(struct phy_device *phydev)
> +{
> +	int ret;
> +
> +	ret = tja11xx_enable_reg_write(phydev);
> +	if (ret)
> +		return ret;
> +
> +	return genphy_soft_reset(phydev);
> +}
> +
> +static int tja11xx_config_init(struct phy_device *phydev)
> +{
> +	int ret;
> +
> +	ret = tja11xx_enable_reg_write(phydev);
> +	if (ret)
> +		return ret;
> +
> +	phydev->irq = PHY_POLL;
> +	phydev->autoneg = AUTONEG_DISABLE;
> +	phydev->speed = SPEED_100;
> +	phydev->duplex = DUPLEX_FULL;
> +	phydev->pause = 0;
> +	phydev->asym_pause = 0;
> +
> +	switch (phydev->phy_id & PHY_ID_MASK) {
> +	case PHY_ID_TJA1100:
> +		ret = phy_modify(phydev, MII_CFG1,
> +				 MII_CFG1_AUTO_OP | MII_CFG1_LED_MODE_MASK |
> +				 MII_CFG1_LED_ENABLE,
> +				 MII_CFG1_AUTO_OP | MII_CFG1_LED_MODE_LINKUP |
> +				 MII_CFG1_LED_ENABLE);
> +		if (ret)
> +			return ret;
> +		break;
> +	case PHY_ID_TJA1101:
> +		ret = phy_set_bits(phydev, MII_COMMCFG, MII_COMMCFG_AUTO_OP);
> +		if (ret)
> +			return ret;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	ret = phy_clear_bits(phydev, MII_CFG1, MII_CFG1_SLEEP_CONFIRM);
> +	if (ret)
> +		return ret;
> +
> +	ret = phy_modify(phydev, MII_CFG2, MII_CFG2_SLEEP_REQUEST_TO,
> +			 MII_CFG2_SLEEP_REQUEST_TO_16MS);
> +	if (ret)
> +		return ret;
> +
> +	ret = tja11xx_wakeup(phydev);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* ACK interrupts by reading the status register */
> +	ret = phy_read(phydev, MII_INTSRC);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int tja11xx_read_status(struct phy_device *phydev)
> +{
> +	int ret;
> +
> +	ret = genphy_update_link(phydev);
> +	if (ret)
> +		return ret;
> +
> +	ret = phy_read(phydev, MII_COMMSTAT);
> +	if (ret < 0)
> +		return ret;
> +
> +	phydev->link = phydev->link && !!(ret & MII_COMMSTAT_LINK_UP);
> +

I think better to read would be:

genphy_update_link();
if (link) {
	get_commstat();
	if (!commstat_link_up)
		link = 0
}

This also avoids the extra read of commstat in case link is down.

After having had a brief look at the data sheet it's not clear to
me how this "link up" bit is different from the standard one in BMSR.
Can they ever have different values?

> +	return 0;
> +}
> +
> +static int tja11xx_get_sset_count(struct phy_device *phydev)
> +{
> +	return ARRAY_SIZE(tja11xx_hw_stats);
> +}
> +
> +static void tja11xx_get_strings(struct phy_device *phydev, u8 *data)
> +{
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(tja11xx_hw_stats); i++) {
> +		strncpy(data + i * ETH_GSTRING_LEN,
> +			tja11xx_hw_stats[i].string, ETH_GSTRING_LEN);
> +	}
> +}
> +
> +static void tja11xx_get_stats(struct phy_device *phydev,
> +			      struct ethtool_stats *stats, u64 *data)
> +{
> +	int i, ret;
> +
> +	for (i = 0; i < ARRAY_SIZE(tja11xx_hw_stats); i++) {
> +		ret = phy_read(phydev, tja11xx_hw_stats[i].reg);
> +		if (ret < 0) {
> +			data[i] = U64_MAX;
> +		} else {
> +			data[i] = ret & tja11xx_hw_stats[i].mask;
> +			data[i] >>= tja11xx_hw_stats[i].off;
> +		}
> +	}
> +}
> +
> +static struct phy_driver tja11xx_driver[] = {
> +	{
> +		.phy_id		= PHY_ID_TJA1100,

Here you may want to use new macro PHY_ID_MATCH_MODEL().
Same for the id table.

> +		.phy_id_mask	= PHY_ID_MASK,
> +		.name		= "NXP TJA1100",
> +		.features       = PHY_BASIC_T1_FEATURES,
> +		.soft_reset	= tja11xx_soft_reset,
> +		.config_init	= tja11xx_config_init,
> +		.read_status	= tja11xx_read_status,
> +		.suspend	= genphy_suspend,
> +		.resume		= genphy_resume,
> +		.set_loopback   = genphy_loopback,
> +		/* Statistics */
> +		.get_sset_count = tja11xx_get_sset_count,
> +		.get_strings	= tja11xx_get_strings,
> +		.get_stats	= tja11xx_get_stats,
> +	}, {
> +		.phy_id		= PHY_ID_TJA1101,
> +		.phy_id_mask	= PHY_ID_MASK,
> +		.name		= "NXP TJA1101",
> +		.features       = PHY_BASIC_T1_FEATURES,
> +		.soft_reset	= tja11xx_soft_reset,
> +		.config_init	= tja11xx_config_init,
> +		.read_status	= tja11xx_read_status,
> +		.suspend	= genphy_suspend,
> +		.resume		= genphy_resume,
> +		.set_loopback   = genphy_loopback,
> +		/* Statistics */
> +		.get_sset_count = tja11xx_get_sset_count,
> +		.get_strings	= tja11xx_get_strings,
> +		.get_stats	= tja11xx_get_stats,
> +	}
> +};
> +
> +module_phy_driver(tja11xx_driver);
> +
> +static struct mdio_device_id __maybe_unused tja11xx_tbl[] = {
> +	{ PHY_ID_TJA1100, PHY_ID_MASK },
> +	{ PHY_ID_TJA1101, PHY_ID_MASK },
> +	{ }
> +};
> +
> +MODULE_DEVICE_TABLE(mdio, tja11xx_tbl);
> +
> +MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
> +MODULE_DESCRIPTION("NXP TJA11xx BoardR-Reach PHY driver");
> +MODULE_LICENSE("GPL");
>