[PATCH v6 10/17] phy: Add driver for rockchip Display Port PHY

Yakir Yang
2015-10-13T01:20:01Z

Hi Kishon

On 10/12/2015 11:02 PM, Kishon Vijay Abraham I wrote:
> Hi,
>
> On Saturday 10 October 2015 09:25 PM, Yakir Yang wrote:
>> This phy driver would control the Rockchip DisplayPort module
>> phy clock and phy power, it is relate to analogix_dp-rockchip
>> dp driver. If you want DP works rightly on rockchip platform,
>> then you should select both of them.
> Add phy driver for the Rockchip DisplayPort PHY module. This is required
> to get DisplayPort working in Rockchip SoCs.

Thanks, take point.

>> Signed-off-by: Yakir Yang <ykk@rock-chips.com>
>> ---
>> Changes in v6: None
>> Changes in v5:
>> - Remove "reg" DT property, cause driver could poweron/poweroff phy via
>> the exist "grf" syscon already. And rename the example DT node from
>> "edp_phy: phy at ff770274" to "edp_phy: edp-phy" directly. (Heiko)
>> - Add deivce_node at the front of driver, update phy_ops type from "static
>> struct" to "static const struct". And correct the input paramters of
>> devm_phy_create() interfaces. (Heiko)
>>
>> Changes in v4:
>> - Add commit message, and remove the redundant rockchip_dp_phy_init()
>> function, move those code to probe() method. And remove driver .owner
>> number. (Kishon)
>>
>> Changes in v3:
>> - Suggest, add rockchip dp phy driver, collect the phy clocks and
>> power control. (Heiko)
>>
>> Changes in v2: None
>>
>> drivers/phy/Kconfig | 7 ++
>> drivers/phy/Makefile | 1 +
>> drivers/phy/phy-rockchip-dp.c | 151 ++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 159 insertions(+)
>> create mode 100644 drivers/phy/phy-rockchip-dp.c
>>
>> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
>> index 47da573..8f2bc4f 100644
>> --- a/drivers/phy/Kconfig
>> +++ b/drivers/phy/Kconfig
>> @@ -310,6 +310,13 @@ config PHY_ROCKCHIP_USB
>> help
>> Enable this to support the Rockchip USB 2.0 PHY.
>>
>> +config PHY_ROCKCHIP_DP
>> + tristate "Rockchip Display Port PHY Driver"
>> + depends on ARCH_ROCKCHIP && OF
>> + select GENERIC_PHY
>> + help
>> + Enable this to support the Rockchip Display Port PHY.
>> +
>> config PHY_ST_SPEAR1310_MIPHY
>> tristate "ST SPEAR1310-MIPHY driver"
>> select GENERIC_PHY
>> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
>> index a5b18c1..e281f35 100644
>> --- a/drivers/phy/Makefile
>> +++ b/drivers/phy/Makefile
>> @@ -34,6 +34,7 @@ phy-exynos-usb2-$(CONFIG_PHY_S5PV210_USB2) += phy-s5pv210-usb2.o
>> obj-$(CONFIG_PHY_EXYNOS5_USBDRD) += phy-exynos5-usbdrd.o
>> obj-$(CONFIG_PHY_QCOM_APQ8064_SATA) += phy-qcom-apq8064-sata.o
>> obj-$(CONFIG_PHY_ROCKCHIP_USB) += phy-rockchip-usb.o
>> +obj-$(CONFIG_PHY_ROCKCHIP_DP) += phy-rockchip-dp.o
>> obj-$(CONFIG_PHY_QCOM_IPQ806X_SATA) += phy-qcom-ipq806x-sata.o
>> obj-$(CONFIG_PHY_ST_SPEAR1310_MIPHY) += phy-spear1310-miphy.o
>> obj-$(CONFIG_PHY_ST_SPEAR1340_MIPHY) += phy-spear1340-miphy.o
>> diff --git a/drivers/phy/phy-rockchip-dp.c b/drivers/phy/phy-rockchip-dp.c
>> new file mode 100644
>> index 0000000..3a2ac120
>> --- /dev/null
>> +++ b/drivers/phy/phy-rockchip-dp.c
>> @@ -0,0 +1,151 @@
>> +/*
>> + * Rockchip DP PHY driver
>> + *
>> + * Copyright (C) 2015 FuZhou Rockchip Co., Ltd.
>> + * Author: Yakir Yang <ykk@@rock-chips.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; either version 2 of the License.
>> + */
>> +
>> +#include <linux/io.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/of_address.h>
>> +#include <linux/clk.h>
>> +#include <linux/phy/phy.h>
>> +#include <linux/regmap.h>
>> +#include <linux/mfd/syscon.h>
>> +#include <linux/platform_device.h>
>> +
>> +#define GRF_SOC_CON12 0x0274
>> +#define GRF_EDP_REF_CLK_SEL_INTER BIT(4)
>> +#define GRF_EDP_PHY_SIDDQ_WRITE_EN BIT(21)
>> +#define GRF_EDP_PHY_SIDDQ_ON 0
>> +#define GRF_EDP_PHY_SIDDQ_OFF BIT(5)
>> +
>> +struct rockchip_dp_phy {
>> + struct device *dev;
>> + struct regmap *grf;
>> + struct clk *phy_24m;
>> +};
>> +
>> +static int rockchip_set_phy_state(struct phy *phy, bool enable)
>> +{
>> + struct rockchip_dp_phy *dp = phy_get_drvdata(phy);
>> + int ret;
>> +
>> + if (enable) {
>> + ret = clk_prepare_enable(dp->phy_24m);
>> + if (ret < 0) {
>> + dev_err(dp->dev, "Can't enable clock 24m %d\n", ret);
>> + return ret;
>> + }
>> +
>> + ret = regmap_write(dp->grf, GRF_SOC_CON12,
>> + GRF_EDP_PHY_SIDDQ_WRITE_EN |
>> + GRF_EDP_PHY_SIDDQ_ON);
>> + } else {
>> + clk_disable_unprepare(dp->phy_24m);
> should clk_disable come after regmap_write? It'll be symmetric to enable?

I don't see there is a strict limit about this, but thanks for your point, I
would like to change this order to:

if (enable) {
// Enable SIDDQ power
// Enable Clock
} else {
// Disable Clock
// Disable SIDDQ power
}

>> + ret = regmap_write(dp->grf, GRF_SOC_CON12,
>> + GRF_EDP_PHY_SIDDQ_WRITE_EN |
>> + GRF_EDP_PHY_SIDDQ_OFF);
> Is this syscon register used only by Display Port PHY? Better to use
> regmap_update API?

Thanks to Heiko explain, writing you actually need to set the
write-enable bit, some kind of hardware regmap_update.

Thanks,
- Yakir

> Thanks
> Kishon
>
>
>