[PATCH v2 2/2] phy: meson: add USB2 PHY support for Meson GXL and GXM
Kishon Vijay Abraham I
kishon at ti.com
Wed Mar 29 03:56:06 PDT 2017
Hi,
On Wednesday 29 March 2017 03:03 AM, Martin Blumenstingl wrote:
> Hi Kishon,
>
> On Sat, Mar 18, 2017 at 2:00 PM, Martin Blumenstingl
> <martin.blumenstingl at googlemail.com> wrote:
>> This adds a new driver for the USB2 PHYs found on Meson GXL and GXM SoCs
>> (both SoCs are using the same USB PHY register layout).
>>
>> The USB2 PHY is a simple PHY which only has a few registers to configure
>> the mode (host/device) and a reset register (to enable/disable the PHY).
>>
>> Unfortunately there are no datasheets available for this PHY. The driver
>> was written by reading the code from Amlogic's GPL kernel sources and
>> by analyzing the registers on an actual GXL and GXM device running the
>> kernel that was shipped on the boards I have.
> gentle ping - did you have time to review this patch in v2 yet?
Have a few comments, see below..
>
>> Signed-off-by: Martin Blumenstingl <martin.blumenstingl at googlemail.com>
>> ---
>> drivers/phy/Kconfig | 14 ++
>> drivers/phy/Makefile | 1 +
>> drivers/phy/phy-meson-gxl-usb2.c | 273 +++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 288 insertions(+)
>> create mode 100644 drivers/phy/phy-meson-gxl-usb2.c
>>
>> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
>> index dc5277ad1b5a..2573e139fd17 100644
>> --- a/drivers/phy/Kconfig
>> +++ b/drivers/phy/Kconfig
>> @@ -510,6 +510,19 @@ config PHY_MESON8B_USB2
>> and GXBB SoCs.
>> If unsure, say N.
>>
>> +config PHY_MESON_GXL_USB
>> + tristate "Meson GXL and GXM USB2 PHY drivers"
>> + default ARCH_MESON
>> + depends on OF && (ARCH_MESON || COMPILE_TEST)
>> + depends on USB_SUPPORT
>> + select USB_COMMON
>> + select GENERIC_PHY
>> + select REGMAP_MMIO
>> + help
>> + Enable this to support the Meson USB2 PHYs found in Meson
>> + GXL and GXM SoCs.
>> + If unsure, say N.
>> +
>> config PHY_NSP_USB3
>> tristate "Broadcom NorthStar plus USB3 PHY driver"
>> depends on OF && (ARCH_BCM_NSP || COMPILE_TEST)
>> @@ -518,4 +531,5 @@ config PHY_NSP_USB3
>> help
>> Enable this to support the Broadcom Northstar plus USB3 PHY.
>> If unsure, say N.
>> +
spurious space..
>> endmenu
>> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
>> index e7b0feb1e125..e680b856e38e 100644
>> --- a/drivers/phy/Makefile
>> +++ b/drivers/phy/Makefile
>> @@ -62,4 +62,5 @@ obj-$(CONFIG_PHY_CYGNUS_PCIE) += phy-bcm-cygnus-pcie.o
>> obj-$(CONFIG_ARCH_TEGRA) += tegra/
>> obj-$(CONFIG_PHY_NS2_PCIE) += phy-bcm-ns2-pcie.o
>> obj-$(CONFIG_PHY_MESON8B_USB2) += phy-meson8b-usb2.o
>> +obj-$(CONFIG_PHY_MESON_GXL_USB) += phy-meson-gxl-usb2.o
>> obj-$(CONFIG_PHY_NSP_USB3) += phy-bcm-nsp-usb3.o
>> diff --git a/drivers/phy/phy-meson-gxl-usb2.c b/drivers/phy/phy-meson-gxl-usb2.c
>> new file mode 100644
>> index 000000000000..4bf646a52c45
>> --- /dev/null
>> +++ b/drivers/phy/phy-meson-gxl-usb2.c
>> @@ -0,0 +1,273 @@
>> +/*
>> + * Meson GXL and GXM USB2 PHY driver
>> + *
>> + * Copyright (C) 2017 Martin Blumenstingl <martin.blumenstingl at googlemail.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
>> + */
>> +
>> +#include <linux/delay.h>
>> +#include <linux/io.h>
>> +#include <linux/module.h>
>> +#include <linux/of_device.h>
>> +#include <linux/regmap.h>
>> +#include <linux/phy/phy.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/usb/of.h>
>> +
>> +/* bits [31:27] are read-only */
>> +#define U2P_R0 0x0
>> + #define U2P_R0_BYPASS_SEL BIT(0)
>> + #define U2P_R0_BYPASS_DM_EN BIT(1)
>> + #define U2P_R0_BYPASS_DP_EN BIT(2)
>> + #define U2P_R0_TXBITSTUFF_ENH BIT(3)
>> + #define U2P_R0_TXBITSTUFF_EN BIT(4)
>> + #define U2P_R0_DM_PULLDOWN BIT(5)
>> + #define U2P_R0_DP_PULLDOWN BIT(6)
>> + #define U2P_R0_DP_VBUS_VLD_EXT_SEL BIT(7)
>> + #define U2P_R0_DP_VBUS_VLD_EXT BIT(8)
>> + #define U2P_R0_ADP_PRB_EN BIT(9)
>> + #define U2P_R0_ADP_DISCHARGE BIT(10)
>> + #define U2P_R0_ADP_CHARGE BIT(11)
>> + #define U2P_R0_DRV_VBUS BIT(12)
>> + #define U2P_R0_ID_PULLUP BIT(13)
>> + #define U2P_R0_LOOPBACK_EN_B BIT(14)
>> + #define U2P_R0_OTG_DISABLE BIT(15)
>> + #define U2P_R0_COMMON_ONN BIT(16)
>> + #define U2P_R0_FSEL_MASK GENMASK(19, 17)
>> + #define U2P_R0_REF_CLK_SEL_MASK GENMASK(21, 20)
>> + #define U2P_R0_POWER_ON_RESET BIT(22)
>> + #define U2P_R0_V_ATE_TEST_EN_B_MASK GENMASK(24, 23)
>> + #define U2P_R0_ID_SET_ID_DQ BIT(25)
>> + #define U2P_R0_ATE_RESET BIT(26)
>> + #define U2P_R0_FSV_MINUS BIT(27)
>> + #define U2P_R0_FSV_PLUS BIT(28)
>> + #define U2P_R0_BYPASS_DM_DATA BIT(29)
>> + #define U2P_R0_BYPASS_DP_DATA BIT(30)
>> +
>> +#define U2P_R1 0x4
>> + #define U2P_R1_BURN_IN_TEST BIT(0)
>> + #define U2P_R1_ACA_ENABLE BIT(1)
>> + #define U2P_R1_DCD_ENABLE BIT(2)
>> + #define U2P_R1_VDAT_SRC_EN_B BIT(3)
>> + #define U2P_R1_VDAT_DET_EN_B BIT(4)
>> + #define U2P_R1_CHARGES_SEL BIT(5)
>> + #define U2P_R1_TX_PREEMP_PULSE_TUNE BIT(6)
>> + #define U2P_R1_TX_PREEMP_AMP_TUNE_MASK GENMASK(8, 7)
>> + #define U2P_R1_TX_RES_TUNE_MASK GENMASK(10, 9)
>> + #define U2P_R1_TX_RISE_TUNE_MASK GENMASK(12, 11)
>> + #define U2P_R1_TX_VREF_TUNE_MASK GENMASK(16, 13)
>> + #define U2P_R1_TX_FSLS_TUNE_MASK GENMASK(20, 17)
>> + #define U2P_R1_TX_HSXV_TUNE_MASK GENMASK(22, 21)
>> + #define U2P_R1_OTG_TUNE_MASK GENMASK(25, 23)
>> + #define U2P_R1_SQRX_TUNE_MASK GENMASK(28, 26)
>> + #define U2P_R1_COMP_DIS_TUNE_MASK GENMASK(31, 29)
>> +
>> +/* bits [31:14] are read-only */
>> +#define U2P_R2 0x8
>> + #define U2P_R2_DATA_IN_MASK GENMASK(3, 0)
>> + #define U2P_R2_DATA_IN_EN_MASK GENMASK(7, 4)
>> + #define U2P_R2_ADDR_MASK GENMASK(11, 8)
>> + #define U2P_R2_DATA_OUT_SEL BIT(12)
>> + #define U2P_R2_CLK BIT(13)
>> + #define U2P_R2_DATA_OUT_MASK GENMASK(17, 14)
>> + #define U2P_R2_ACA_PIN_RANGE_C BIT(18)
>> + #define U2P_R2_ACA_PIN_RANGE_B BIT(19)
>> + #define U2P_R2_ACA_PIN_RANGE_A BIT(20)
>> + #define U2P_R2_ACA_PIN_GND BIT(21)
>> + #define U2P_R2_ACA_PIN_FLOAT BIT(22)
>> + #define U2P_R2_CHARGE_DETECT BIT(23)
>> + #define U2P_R2_DEVICE_SESSION_VALID BIT(24)
>> + #define U2P_R2_ADP_PROBE BIT(25)
>> + #define U2P_R2_ADP_SENSE BIT(26)
>> + #define U2P_R2_SESSION_END BIT(27)
>> + #define U2P_R2_VBUS_VALID BIT(28)
>> + #define U2P_R2_B_VALID BIT(29)
>> + #define U2P_R2_A_VALID BIT(30)
>> + #define U2P_R2_ID_DIG BIT(31)
>> +
>> +#define U2P_R3 0xc
>> +
>> +#define RESET_COMPLETE_TIME 500
>> +
>> +struct phy_meson_gxl_usb2_priv {
>> + struct regmap *regmap;
>> + enum phy_mode mode;
>> + int is_enabled;
>> +};
>> +
>> +static const struct regmap_config phy_meson_gxl_usb2_regmap_conf = {
>> + .reg_bits = 8,
>> + .val_bits = 32,
>> + .reg_stride = 4,
>> + .max_register = U2P_R3,
>> +};
>> +
>> +static int phy_meson_gxl_usb2_reset(struct phy *phy)
>> +{
>> + struct phy_meson_gxl_usb2_priv *priv = phy_get_drvdata(phy);
>> +
>> + if (priv->is_enabled) {
>> + /* reset the PHY and wait until settings are stabilized */
>> + regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_POWER_ON_RESET,
>> + U2P_R0_POWER_ON_RESET);
>> + udelay(RESET_COMPLETE_TIME);
>> + regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_POWER_ON_RESET,
>> + 0);
>> + udelay(RESET_COMPLETE_TIME);
>> + }
Instead of having big if condition blocks, it could be
if (!priv->is_enabled)
return 0
the configuration when priv->is_enabled is true should go here.
>> +
>> + return 0;
>> +}
>> +
>> +static int phy_meson_gxl_usb2_set_mode(struct phy *phy, enum phy_mode mode)
>> +{
>> + struct phy_meson_gxl_usb2_priv *priv = phy_get_drvdata(phy);
>> +
>> + switch (mode) {
>> + case PHY_MODE_USB_HOST:
>> + case PHY_MODE_USB_OTG:
>> + regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_DM_PULLDOWN,
>> + U2P_R0_DM_PULLDOWN);
>> + regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_DP_PULLDOWN,
>> + U2P_R0_DP_PULLDOWN);
>> + regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_ID_PULLUP, 0);
>> + break;
>> +
>> + case PHY_MODE_USB_DEVICE:
>> + regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_DM_PULLDOWN,
>> + 0);
>> + regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_DP_PULLDOWN,
>> + 0);
>> + regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_ID_PULLUP,
>> + U2P_R0_ID_PULLUP);
>> + break;
>> +
>> + default:
>> + return -EINVAL;
>> + }
>> +
>> + phy_meson_gxl_usb2_reset(phy);
>> +
>> + priv->mode = mode;
>> +
>> + return 0;
>> +}
>> +
>> +static int phy_meson_gxl_usb2_power_off(struct phy *phy)
>> +{
>> + struct phy_meson_gxl_usb2_priv *priv = phy_get_drvdata(phy);
>> +
>> + priv->is_enabled = 0;
>> +
>> + /* power off the PHY by putting it into reset mode */
>> + regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_POWER_ON_RESET,
>> + U2P_R0_POWER_ON_RESET);
>> +
>> + return 0;
>> +}
>> +
>> +static int phy_meson_gxl_usb2_power_on(struct phy *phy)
>> +{
>> + struct phy_meson_gxl_usb2_priv *priv = phy_get_drvdata(phy);
>> + int ret;
>> +
>> + priv->is_enabled = 1;
>> +
>> + /* power on the PHY by taking it out of reset mode */
>> + regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_POWER_ON_RESET, 0);
>> +
>> + ret = phy_meson_gxl_usb2_set_mode(phy, priv->mode);
Since this is already part of phy_ops, the consumer of this phy will take care
of setting the mode right?
>> + if (ret) {
>> + phy_meson_gxl_usb2_power_off(phy);
This would mess up the reference count in phy_core, since this function is also
part of the phy_ops. The consumer should be responsible for powering off the phy.
Thanks
Kishon
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