Thread (31 messages) 31 messages, 9 authors, 2017-01-16

Re: [PATCH V2 2/5] phy: phy-exynos-pcie: Add support for Exynos PCIe phy

From: Jaehoon Chung <jh80.chung@samsung.com>
Date: 2017-01-16 11:00:30
Also in: linux-pci, linux-samsung-soc, lkml

Hi,

On 01/16/2017 05:37 PM, Kishon Vijay Abraham I wrote:
Hi,

On Wednesday 04 January 2017 06:04 PM, Jaehoon Chung wrote:
quoted
This patch supports to use Generic Phy framework for Exynos PCIe phy.
When Exynos that supported the pcie want to use the PCIe,
it needs to control the phy resgister.
But it should be more complex to control in their own PCIe device drivers.

Currently, there is an exynos5440 case to support the pcie.
So this driver is based on Exynos5440 PCIe.
In future, will support the Other exynos SoCs likes exynos5433, exynos7.
please re-write the commit message.
Will update the commit-message
quoted
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
---
Changelog on V2:
- Not include the codes relevant to pci-exynos.
- Remove the getting child node.

 drivers/phy/Kconfig           |   9 ++
 drivers/phy/Makefile          |   1 +
 drivers/phy/phy-exynos-pcie.c | 280 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 290 insertions(+)
 create mode 100644 drivers/phy/phy-exynos-pcie.c
diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index e8eb7f2..2dddef4 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -331,6 +331,15 @@ config PHY_EXYNOS5_USBDRD
 	  This driver provides PHY interface for USB 3.0 DRD controller
 	  present on Exynos5 SoC series.
 
+config PHY_EXYNOS_PCIE
+	bool "Exynos PCIe PHY driver"
+	depends on ARCH_EXYNOS && OF
include COMPILE_TEST
Ok.
quoted
+	depends on PCI_EXYNOS
PCI_EXYNOS should depend on PHY_EXYNOS_PCIE if at all required. Or else do away
with this dependency.
Ok.
quoted
+	select GENERIC_PHY
+	help
+	  Enable PCIe PHY support for Exynos SoC series.
+	  This driver provides PHY interface for Exynos PCIe controller.
+
 config PHY_PISTACHIO_USB
 	tristate "IMG Pistachio USB2.0 PHY driver"
 	depends on MACH_PISTACHIO
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index 65eb2f4..081aeb4 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -37,6 +37,7 @@ phy-exynos-usb2-$(CONFIG_PHY_EXYNOS4X12_USB2)	+= phy-exynos4x12-usb2.o
 phy-exynos-usb2-$(CONFIG_PHY_EXYNOS5250_USB2)	+= phy-exynos5250-usb2.o
 phy-exynos-usb2-$(CONFIG_PHY_S5PV210_USB2)	+= phy-s5pv210-usb2.o
 obj-$(CONFIG_PHY_EXYNOS5_USBDRD)	+= phy-exynos5-usbdrd.o
+obj-$(CONFIG_PHY_EXYNOS_PCIE)	+= phy-exynos-pcie.o
 obj-$(CONFIG_PHY_QCOM_APQ8064_SATA)	+= phy-qcom-apq8064-sata.o
 obj-$(CONFIG_PHY_ROCKCHIP_USB) += phy-rockchip-usb.o
 obj-$(CONFIG_PHY_ROCKCHIP_INNO_USB2)	+= phy-rockchip-inno-usb2.o
diff --git a/drivers/phy/phy-exynos-pcie.c b/drivers/phy/phy-exynos-pcie.c
new file mode 100644
index 0000000..b57f49b
--- /dev/null
+++ b/drivers/phy/phy-exynos-pcie.c
@@ -0,0 +1,280 @@
+/*
+ * Samsung EXYNOS SoC series PCIe PHY driver
+ *
+ * Phy provider for PCIe controller on Exynos SoC series
+ *
+ * Copyright (C) 2016 Samsung Electronics Co., Ltd.
2017?
When i had posted the first version, it was 2016.. :)
quoted
+ * Jaehoon Chung [off-list ref]
+ *
+ * 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.
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/phy/phy.h>
+#include <linux/regmap.h>
+
+/* PCIe Purple registers */
+#define PCIE_PHY_GLOBAL_RESET		0x000
+#define PCIE_PHY_COMMON_RESET		0x004
+#define PCIE_PHY_CMN_REG		0x008
+#define PCIE_PHY_MAC_RESET		0x00c
+#define PCIE_PHY_PLL_LOCKED		0x010
+#define PCIE_PHY_TRSVREG_RESET		0x020
+#define PCIE_PHY_TRSV_RESET		0x024
Please use BIT() macro for bit definitions.
Ok.
quoted
+
+/* PCIe PHY registers */
+#define PCIE_PHY_IMPEDANCE		0x004
+#define PCIE_PHY_PLL_DIV_0		0x008
+#define PCIE_PHY_PLL_BIAS		0x00c
+#define PCIE_PHY_DCC_FEEDBACK		0x014
+#define PCIE_PHY_PLL_DIV_1		0x05c
+#define PCIE_PHY_COMMON_POWER		0x064
+#define PCIE_PHY_COMMON_PD_CMN		BIT(3)
+#define PCIE_PHY_TRSV0_EMP_LVL		0x084
+#define PCIE_PHY_TRSV0_DRV_LVL		0x088
+#define PCIE_PHY_TRSV0_RXCDR		0x0ac
+#define PCIE_PHY_TRSV0_POWER		0x0c4
+#define PCIE_PHY_TRSV0_PD_TSV		BIT(7)
+#define PCIE_PHY_TRSV0_LVCC		0x0dc
+#define PCIE_PHY_TRSV1_EMP_LVL		0x144
+#define PCIE_PHY_TRSV1_RXCDR		0x16c
+#define PCIE_PHY_TRSV1_POWER		0x184
+#define PCIE_PHY_TRSV1_PD_TSV		BIT(7)
+#define PCIE_PHY_TRSV1_LVCC		0x19c
+#define PCIE_PHY_TRSV2_EMP_LVL		0x204
+#define PCIE_PHY_TRSV2_RXCDR		0x22c
+#define PCIE_PHY_TRSV2_POWER		0x244
+#define PCIE_PHY_TRSV2_PD_TSV		BIT(7)
+#define PCIE_PHY_TRSV2_LVCC		0x25c
+#define PCIE_PHY_TRSV3_EMP_LVL		0x2c4
+#define PCIE_PHY_TRSV3_RXCDR		0x2ec
+#define PCIE_PHY_TRSV3_POWER		0x304
+#define PCIE_PHY_TRSV3_PD_TSV		BIT(7)
+#define PCIE_PHY_TRSV3_LVCC		0x31c
+
+struct exynos_pcie_phy_data {
+	struct phy_ops	*ops;
+};
+
+/* For Exynos pcie phy */
+struct exynos_pcie_phy {
+	const struct exynos_pcie_phy_data *drv_data;
+	void __iomem *phy_base;
+	void __iomem *blk_base; /* For exynos5440 */
+};
+
+static void exynos_pcie_phy_writel(void __iomem *base, u32 val, u32 offset)
+{
+	writel(val, base + offset);
+}
+
+static u32 exynos_pcie_phy_readl(void __iomem *base, u32 offset)
+{
+	return readl(base + offset);
+}
+
+/* For Exynos5440 specific functions */
+static int exynos5440_pcie_phy_init(struct phy *phy)
+{
+	struct exynos_pcie_phy *ep = phy_get_drvdata(phy);
+
+	/* DCC feedback control off */
+	exynos_pcie_phy_writel(ep->phy_base, 0x29, PCIE_PHY_DCC_FEEDBACK);
+
+	/* set TX/RX impedance */
+	exynos_pcie_phy_writel(ep->phy_base, 0xd5, PCIE_PHY_IMPEDANCE);
+
+	/* set 50Mhz PHY clock */
+	exynos_pcie_phy_writel(ep->phy_base, 0x14, PCIE_PHY_PLL_DIV_0);
+	exynos_pcie_phy_writel(ep->phy_base, 0x12, PCIE_PHY_PLL_DIV_1);
+
+	/* set TX Differential output for lane 0 */
+	exynos_pcie_phy_writel(ep->phy_base, 0x7f, PCIE_PHY_TRSV0_DRV_LVL);
+
+	/* set TX Pre-emphasis Level Control for lane 0 to minimum */
+	exynos_pcie_phy_writel(ep->phy_base, 0x0, PCIE_PHY_TRSV0_EMP_LVL);
+
+	/* set RX clock and data recovery bandwidth */
+	exynos_pcie_phy_writel(ep->phy_base, 0xe7, PCIE_PHY_PLL_BIAS);
+	exynos_pcie_phy_writel(ep->phy_base, 0x82, PCIE_PHY_TRSV0_RXCDR);
+	exynos_pcie_phy_writel(ep->phy_base, 0x82, PCIE_PHY_TRSV1_RXCDR);
+	exynos_pcie_phy_writel(ep->phy_base, 0x82, PCIE_PHY_TRSV2_RXCDR);
+	exynos_pcie_phy_writel(ep->phy_base, 0x82, PCIE_PHY_TRSV3_RXCDR);
+
+	/* change TX Pre-emphasis Level Control for lanes */
+	exynos_pcie_phy_writel(ep->phy_base, 0x39, PCIE_PHY_TRSV0_EMP_LVL);
+	exynos_pcie_phy_writel(ep->phy_base, 0x39, PCIE_PHY_TRSV1_EMP_LVL);
+	exynos_pcie_phy_writel(ep->phy_base, 0x39, PCIE_PHY_TRSV2_EMP_LVL);
+	exynos_pcie_phy_writel(ep->phy_base, 0x39, PCIE_PHY_TRSV3_EMP_LVL);
+
+	/* set LVCC */
+	exynos_pcie_phy_writel(ep->phy_base, 0x20, PCIE_PHY_TRSV0_LVCC);
+	exynos_pcie_phy_writel(ep->phy_base, 0xa0, PCIE_PHY_TRSV1_LVCC);
+	exynos_pcie_phy_writel(ep->phy_base, 0xa0, PCIE_PHY_TRSV2_LVCC);
+	exynos_pcie_phy_writel(ep->phy_base, 0xa0, PCIE_PHY_TRSV3_LVCC);
I'm starting to dis-like all this hard-coded hw params. All this should come
from dt. Define a dt binding like this for all hw params..
	phy,tx-differential = <val, reg-offset, mask>

and have one API in phy-core to do all these settings.
Will check.
quoted
+
+	/* pulse for common reset */
+	exynos_pcie_phy_writel(ep->blk_base, 1, PCIE_PHY_COMMON_RESET);
+	udelay(500);
how did you get this delay value? Adding a comment might help.
Well..Actually i don't know why udelay(500) was defined.
When i had started the refactoring pci-exynos, there was one problem..
I didn't have Exynos5440 TRM and information..i can't check anything for exyno5440.
(I don't know who is using EXYNOS5440 pci.)

the entire codes are just moved from pci-exynos.c.

When i want to upstream exynos5433 pcie, first step is the cleaning pci-exynos.c relevant to exynos5440.
It was too complex to support the other Exynos SoCs.

Otherwise, it needs to add the new file for exynos5433.
quoted
+	exynos_pcie_phy_writel(ep->blk_base, 0, PCIE_PHY_COMMON_RESET);
+
+	return 0;
+}
+
+static int exynos5440_pcie_phy_power_on(struct phy *phy)
+{
+	struct exynos_pcie_phy *ep = phy_get_drvdata(phy);
+	u32 val;
+
+	exynos_pcie_phy_writel(ep->blk_base, 0, PCIE_PHY_COMMON_RESET);
+	exynos_pcie_phy_writel(ep->blk_base, 0, PCIE_PHY_CMN_REG);
+	exynos_pcie_phy_writel(ep->blk_base, 0, PCIE_PHY_TRSVREG_RESET);
+	exynos_pcie_phy_writel(ep->blk_base, 0, PCIE_PHY_TRSV_RESET);
+
+	val = exynos_pcie_phy_readl(ep->phy_base, PCIE_PHY_COMMON_POWER);
+	val &= ~PCIE_PHY_COMMON_PD_CMN;
+	exynos_pcie_phy_writel(ep->phy_base, val, PCIE_PHY_COMMON_POWER);
+
+	val = exynos_pcie_phy_readl(ep->phy_base, PCIE_PHY_TRSV0_POWER);
+	val &= ~PCIE_PHY_TRSV0_PD_TSV;
+	exynos_pcie_phy_writel(ep->phy_base, val, PCIE_PHY_TRSV0_POWER);
+
+	val = exynos_pcie_phy_readl(ep->phy_base, PCIE_PHY_TRSV1_POWER);
+	val &= ~PCIE_PHY_TRSV1_PD_TSV;
+	exynos_pcie_phy_writel(ep->phy_base, val, PCIE_PHY_TRSV1_POWER);
+
+	val = exynos_pcie_phy_readl(ep->phy_base, PCIE_PHY_TRSV2_POWER);
+	val &= ~PCIE_PHY_TRSV2_PD_TSV;
+	exynos_pcie_phy_writel(ep->phy_base, val, PCIE_PHY_TRSV2_POWER);
+
+	val = exynos_pcie_phy_readl(ep->phy_base, PCIE_PHY_TRSV3_POWER);
+	val &= ~PCIE_PHY_TRSV3_PD_TSV;
+	exynos_pcie_phy_writel(ep->phy_base, val, PCIE_PHY_TRSV3_POWER);
+
+	return 0;
+}
+
+static int exynos5440_pcie_phy_power_off(struct phy *phy)
+{
+	struct exynos_pcie_phy *ep = phy_get_drvdata(phy);
+	u32 val;
+
+	while (exynos_pcie_phy_readl(ep->phy_base,
+				PCIE_PHY_PLL_LOCKED) == 0) {
+		val = exynos_pcie_phy_readl(ep->blk_base,
+				PCIE_PHY_PLL_LOCKED);
+		dev_info(&phy->dev, "PLL Locked: 0x%x\n", val);
+	}
+
+	val = exynos_pcie_phy_readl(ep->phy_base, PCIE_PHY_COMMON_POWER);
+	val |= PCIE_PHY_COMMON_PD_CMN;
+	exynos_pcie_phy_writel(ep->phy_base, val, PCIE_PHY_COMMON_POWER);
+
+	val = exynos_pcie_phy_readl(ep->phy_base, PCIE_PHY_TRSV0_POWER);
+	val |= PCIE_PHY_TRSV0_PD_TSV;
+	exynos_pcie_phy_writel(ep->phy_base, val, PCIE_PHY_TRSV0_POWER);
+
+	val = exynos_pcie_phy_readl(ep->phy_base, PCIE_PHY_TRSV1_POWER);
+	val |= PCIE_PHY_TRSV1_PD_TSV;
+	exynos_pcie_phy_writel(ep->phy_base, val, PCIE_PHY_TRSV1_POWER);
+
+	val = exynos_pcie_phy_readl(ep->phy_base, PCIE_PHY_TRSV2_POWER);
+	val |= PCIE_PHY_TRSV2_PD_TSV;
+	exynos_pcie_phy_writel(ep->phy_base, val, PCIE_PHY_TRSV2_POWER);
+
+	val = exynos_pcie_phy_readl(ep->phy_base, PCIE_PHY_TRSV3_POWER);
+	val |= PCIE_PHY_TRSV3_PD_TSV;
+	exynos_pcie_phy_writel(ep->phy_base, val, PCIE_PHY_TRSV3_POWER);
+
+	return 0;
+}
+
+static int exynos5440_pcie_phy_reset(struct phy *phy)
+{
+	struct exynos_pcie_phy *ep = phy_get_drvdata(phy);
+
+	exynos_pcie_phy_writel(ep->blk_base, 0, PCIE_PHY_MAC_RESET);
+	exynos_pcie_phy_writel(ep->blk_base, 1, PCIE_PHY_GLOBAL_RESET);
+	exynos_pcie_phy_writel(ep->blk_base, 0, PCIE_PHY_GLOBAL_RESET);
+
+	return 0;
+}
+
+static struct phy_ops exynos5440_phy_ops = {
+	.init	= exynos5440_pcie_phy_init,
+	.power_on = exynos5440_pcie_phy_power_on,
+	.power_off = exynos5440_pcie_phy_power_off,
+	.reset	= exynos5440_pcie_phy_reset,
add .owner
Will fix.
quoted
+};
+
+static const struct exynos_pcie_phy_data exynos5440_pcie_phy_data = {
+	.ops		= &exynos5440_phy_ops,
why do you need a wrapper for phy_ops?
My main goal is the upstreaming exynos5433 pci, not exynos5440.
There are many different with exynos5440 and exynos5433.
As i know, only exynos5440 has the big different with other Exynos variants.

I think i can be removed in this patch. When i upstream the other SoCs, I will use the wrapper.

Best Regards,
Jaehoon Chung
quoted
+};
+
+static const struct of_device_id exynos_pcie_phy_match[] = {
+	{
+		.compatible = "samsung,exynos5440-pcie-phy",
+		.data = &exynos5440_pcie_phy_data,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, exynos_pcie_phy_match);
+
+static int exynos_pcie_phy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct exynos_pcie_phy *exynos_phy;
+	struct phy *generic_phy;
+	struct phy_provider *phy_provider;
+	struct resource *res;
+	const struct exynos_pcie_phy_data *drv_data;
+
+	drv_data = of_device_get_match_data(dev);
+	if (!drv_data)
+		return -ENODEV;
+
+	exynos_phy = devm_kzalloc(dev, sizeof(*exynos_phy), GFP_KERNEL);
+	if (!exynos_phy)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	exynos_phy->phy_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(exynos_phy->phy_base))
+		return PTR_ERR(exynos_phy->phy_base);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	exynos_phy->blk_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(exynos_phy->phy_base))
+		return PTR_ERR(exynos_phy->phy_base);
+
+	exynos_phy->drv_data = drv_data;
+
+	generic_phy = devm_phy_create(dev, dev->of_node, drv_data->ops);
+	if (IS_ERR(generic_phy)) {
+		dev_err(dev, "failed to create PHY\n");
+		return PTR_ERR(generic_phy);
+	}
+
+	phy_set_drvdata(generic_phy, exynos_phy);
+	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+
+	return PTR_ERR_OR_ZERO(phy_provider);
+}
+
+static struct platform_driver exynos_pcie_phy_driver = {
+	.probe	= exynos_pcie_phy_probe,
+	.driver = {
+		.of_match_table	= exynos_pcie_phy_match,
+		.name		= "exynos_pcie_phy",
+	}
+};
+module_platform_driver(exynos_pcie_phy_driver);
Thanks
Kishon
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