Re: [PATCH 1/2] phy: qcom: Add driver for QCOM IPQ806x SATA PHY

[Kishon Vijay Abraham I <kishon@ti.com>]

Hi,

On Friday 13 June 2014 12:48 AM, Kumar Gala wrote:
> Add a PHY driver for uses with AHCI based SATA controller driver on the
> IPQ806x family of SoCs.
> 
> Signed-off-by: Kumar Gala <galak@codeaurora.org>
> ---
>  drivers/phy/Kconfig                 |   6 ++
>  drivers/phy/Makefile                |   1 +
>  drivers/phy/phy-qcom-ipq806x-sata.c | 204 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 211 insertions(+)
>  create mode 100644 drivers/phy/phy-qcom-ipq806x-sata.c
> 
> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
> index 16a2f06..52bfb93 100644
> --- a/drivers/phy/Kconfig
> +++ b/drivers/phy/Kconfig
> @@ -178,4 +178,10 @@ config PHY_XGENE
>  	help
>  	  This option enables support for APM X-Gene SoC multi-purpose PHY.
>  
> +config PHY_QCOM_IPQ806X_SATA
> +	tristate "Qualcomm IPQ806x SATA SerDes/PHY driver"
> +	depends on ARCH_QCOM
> +	depends on OF
depends on HAS_IOMEM?
> +	select GENERIC_PHY
> +
>  endmenu
> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
> index b4f1d57..d950317 100644
> --- a/drivers/phy/Makefile
> +++ b/drivers/phy/Makefile
> @@ -20,3 +20,4 @@ phy-exynos-usb2-$(CONFIG_PHY_EXYNOS4X12_USB2)	+= phy-exynos4x12-usb2.o
>  phy-exynos-usb2-$(CONFIG_PHY_EXYNOS5250_USB2)	+= phy-exynos5250-usb2.o
>  obj-$(CONFIG_PHY_EXYNOS5_USBDRD)	+= phy-exynos5-usbdrd.o
>  obj-$(CONFIG_PHY_XGENE)			+= phy-xgene.o
> +obj-$(CONFIG_PHY_QCOM_IPQ806X_SATA)	+= phy-qcom-ipq806x-sata.o
> diff --git a/drivers/phy/phy-qcom-ipq806x-sata.c b/drivers/phy/phy-qcom-ipq806x-sata.c
> new file mode 100644
> index 0000000..fc57340
> --- /dev/null
> +++ b/drivers/phy/phy-qcom-ipq806x-sata.c
> @@ -0,0 +1,204 @@
> +/*
> + * Copyright (c) 2014, The Linux Foundation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/time.h>
> +#include <linux/delay.h>
> +#include <linux/clk.h>
> +#include <linux/slab.h>
> +#include <linux/platform_device.h>
> +#include <linux/phy/phy.h>
> +
> +struct qcom_ipq806x_sata_phy {
> +	struct device *dev;

dev is not used anywhere. remove it.
> +	void __iomem *mmio;
> +	struct clk *cfg_clk;
> +};
> +
> +#define __set(v, a, b)	(((v) << (b)) & GENMASK(a, b))
> +
> +#define SATA_PHY_P0_PARAM0		0x200
> +#define SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN3(x)	__set(x, 17, 12)
> +#define SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN3_MASK	GENMASK(17, 12)
> +#define SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN2(x)	__set(x, 11, 6)
> +#define SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN2_MASK	GENMASK(11, 6)
> +#define SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN1(x)	__set(x, 5, 0)
> +#define SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN1_MASK	GENMASK(5, 0)
> +
> +#define SATA_PHY_P0_PARAM1		0x204
> +#define SATA_PHY_P0_PARAM1_RESERVED_BITS31_21(x)	__set(x, 31, 21)
> +#define SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN3(x)	__set(x, 20, 14)
> +#define SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN3_MASK	GENMASK(20, 14)
> +#define SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN2(x)	__set(x, 13, 7)
> +#define SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN2_MASK	GENMASK(13, 7)
> +#define SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN1(x)	__set(x, 6, 0)
> +#define SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN1_MASK	GENMASK(6, 0)
> +
> +#define SATA_PHY_P0_PARAM2		0x208
> +#define SATA_PHY_P0_PARAM2_RX_EQ(x)	__set(x, 20, 18)
> +#define SATA_PHY_P0_PARAM2_RX_EQ_MASK	GENMASK(20, 18)
> +
> +#define SATA_PHY_P0_PARAM3		0x20C
> +#define SATA_PHY_SSC_EN			0x8
> +#define SATA_PHY_P0_PARAM4		0x210
> +#define SATA_PHY_REF_SSP_EN		0x2
> +#define SATA_PHY_RESET			0x1
> +
> +static inline void qcom_ipq806x_sata_delay_us(unsigned int delay)
> +{
> +	/* sleep for max. 50us more to combine processor wakeups */
> +	usleep_range(delay, delay + 50);
> +}
> +
> +static int qcom_ipq806x_sata_phy_init(struct phy *generic_phy)
> +{
> +	struct qcom_ipq806x_sata_phy *phy = phy_get_drvdata(generic_phy);
> +	u32 reg = 0;
> +
> +	/* Setting SSC_EN to 1 */
> +	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM3);

Why readl_relaxed?
> +	reg = reg | SATA_PHY_SSC_EN;
> +	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM3);
> +
> +	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM0) &
> +			~(SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN3_MASK |
> +			  SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN2_MASK |
> +			  SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN1_MASK);
> +	reg |= SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN3(0xf);
> +	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM0);
> +
> +	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM1) &
> +			~(SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN3_MASK |
> +			  SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN2_MASK |
> +			  SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN1_MASK);
> +	reg |= SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN3(0x55) |
> +		SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN2(0x55) |
> +		SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN1(0x55);
> +	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM1);
> +
> +	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM2) &
> +		~SATA_PHY_P0_PARAM2_RX_EQ_MASK;
> +	reg |= SATA_PHY_P0_PARAM2_RX_EQ(0x3);
> +	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM2);
> +
> +	/* Setting PHY_RESET to 1 */
> +	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM4);
> +	reg = reg | SATA_PHY_RESET;
> +	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM4);
> +
> +	/* Setting REF_SSP_EN to 1 */
> +	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM4);
> +	reg = reg | SATA_PHY_REF_SSP_EN | SATA_PHY_RESET;
> +	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM4);
> +	mb();
> +	qcom_ipq806x_sata_delay_us(20);
> +
> +	/* Clearing PHY_RESET to 0 */
> +	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM4);
> +	reg = reg & ~SATA_PHY_RESET;
> +	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM4);
> +
> +	return 0;
> +}
> +
> +static int qcom_ipq806x_sata_phy_exit(struct phy *generic_phy)
> +{
> +	struct qcom_ipq806x_sata_phy *phy = phy_get_drvdata(generic_phy);
> +	u32 reg = 0;
> +
> +	/* Setting PHY_RESET to 1 */
> +	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM4);
> +	reg = reg | SATA_PHY_RESET;
> +	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM4);
> +
> +	return 0;
> +}
> +
> +static struct phy_ops qcom_ipq806x_sata_phy_ops = {
> +	.init		= qcom_ipq806x_sata_phy_init,
> +	.exit		= qcom_ipq806x_sata_phy_exit,
> +	.owner		= THIS_MODULE,
> +};
> +
> +static int qcom_ipq806x_sata_phy_probe(struct platform_device *pdev)
> +{
> +	struct qcom_ipq806x_sata_phy *phy;
> +	struct device *dev = &pdev->dev;
> +	struct resource *res;
> +	struct phy_provider *phy_provider;
> +	struct phy *generic_phy;
> +	int ret;
> +
> +	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
> +	if (!phy) {
> +		dev_err(dev, "%s: failed to allocate phy\n", __func__);
> +		return -ENOMEM;
> +	}
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	phy->mmio = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(phy->mmio)) {
> +		dev_err(dev, "%s: phy mmio get resource failed\n", __func__);
> +		return PTR_ERR(phy->mmio);
> +	}
> +
> +	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
> +	if (IS_ERR(phy_provider)) {
> +		dev_err(dev, "%s: failed to register phy\n", __func__);
> +		return PTR_ERR(phy_provider);
> +	}

phy_provider_register should be the last step. Move it after phy_set_drvdata().

Thanks
Kishon