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linux/drivers/phy/samsung/phy-exynos-pcie.c
Marek Szyprowski f2812227bb phy: samsung: phy-exynos-pcie: sanitize init/power_on callbacks 
The exynos-pcie driver called phy_power_on() before phy_init() for some
historical reasons. However the generic PHY framework assumes that the
proper sequence is to call phy_init() first, then phy_power_on(). The
operations done by both functions should be considered as one action and as
such they are called by the exynos-pcie driver (without doing anything
between them). The initialization is just a sequence of register writes,
which cannot be altered without breaking the hardware operation.

To match the generic PHY framework requirement, simply move all register
writes to the phy_init()/phy_exit() and drop power_on()/power_off()
callbacks. This way the driver will also work with the old (incorrect)
PHY initialization call sequence.

Link: https://lore.kernel.org/r/20220628220409.26545-1-m.szyprowski@samsung.com
Reported-by: Bjorn Helgaas <helgaas@kernel.org>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Chanho Park <chanho61.park@samsung.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-By: Vinod Koul <vkoul@kernel.org>
2022-08-01 15:25:12 -05:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Samsung Exynos SoC series PCIe PHY driver
*
* Phy provider for PCIe controller on Exynos SoC series
*
* Copyright (C) 2017-2020 Samsung Electronics Co., Ltd.
* Jaehoon Chung <jh80.chung@samsung.com>
*/
#include <linux/io.h>
#include <linux/mfd/syscon.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/phy/phy.h>
#include <linux/regmap.h>
#define PCIE_PHY_OFFSET(x) ((x) * 0x4)
/* Sysreg FSYS register offsets and bits for Exynos5433 */
#define PCIE_EXYNOS5433_PHY_MAC_RESET 0x0208
#define PCIE_MAC_RESET_MASK 0xFF
#define PCIE_MAC_RESET BIT(4)
#define PCIE_EXYNOS5433_PHY_L1SUB_CM_CON 0x1010
#define PCIE_REFCLK_GATING_EN BIT(0)
#define PCIE_EXYNOS5433_PHY_COMMON_RESET 0x1020
#define PCIE_PHY_RESET BIT(0)
#define PCIE_EXYNOS5433_PHY_GLOBAL_RESET 0x1040
#define PCIE_GLOBAL_RESET BIT(0)
#define PCIE_REFCLK BIT(1)
#define PCIE_REFCLK_MASK 0x16
#define PCIE_APP_REQ_EXIT_L1_MODE BIT(5)
/* PMU PCIE PHY isolation control */
#define EXYNOS5433_PMU_PCIE_PHY_OFFSET 0x730
/* For Exynos pcie phy */
struct exynos_pcie_phy {
void __iomem *base;
struct regmap *pmureg;
struct regmap *fsysreg;
};
static void exynos_pcie_phy_writel(void __iomem *base, u32 val, u32 offset)
{
writel(val, base + offset);
}
/* Exynos5433 specific functions */
static int exynos5433_pcie_phy_init(struct phy *phy)
{
struct exynos_pcie_phy *ep = phy_get_drvdata(phy);
regmap_update_bits(ep->pmureg, EXYNOS5433_PMU_PCIE_PHY_OFFSET,
BIT(0), 1);
regmap_update_bits(ep->fsysreg, PCIE_EXYNOS5433_PHY_GLOBAL_RESET,
PCIE_APP_REQ_EXIT_L1_MODE, 0);
regmap_update_bits(ep->fsysreg, PCIE_EXYNOS5433_PHY_L1SUB_CM_CON,
PCIE_REFCLK_GATING_EN, 0);
regmap_update_bits(ep->fsysreg, PCIE_EXYNOS5433_PHY_COMMON_RESET,
PCIE_PHY_RESET, 1);
regmap_update_bits(ep->fsysreg, PCIE_EXYNOS5433_PHY_MAC_RESET,
PCIE_MAC_RESET, 0);
/* PHY refclk 24MHz */
regmap_update_bits(ep->fsysreg, PCIE_EXYNOS5433_PHY_GLOBAL_RESET,
PCIE_REFCLK_MASK, PCIE_REFCLK);
regmap_update_bits(ep->fsysreg, PCIE_EXYNOS5433_PHY_GLOBAL_RESET,
PCIE_GLOBAL_RESET, 0);
exynos_pcie_phy_writel(ep->base, 0x11, PCIE_PHY_OFFSET(0x3));
/* band gap reference on */
exynos_pcie_phy_writel(ep->base, 0, PCIE_PHY_OFFSET(0x20));
exynos_pcie_phy_writel(ep->base, 0, PCIE_PHY_OFFSET(0x4b));
/* jitter tuning */
exynos_pcie_phy_writel(ep->base, 0x34, PCIE_PHY_OFFSET(0x4));
exynos_pcie_phy_writel(ep->base, 0x02, PCIE_PHY_OFFSET(0x7));
exynos_pcie_phy_writel(ep->base, 0x41, PCIE_PHY_OFFSET(0x21));
exynos_pcie_phy_writel(ep->base, 0x7F, PCIE_PHY_OFFSET(0x14));
exynos_pcie_phy_writel(ep->base, 0xC0, PCIE_PHY_OFFSET(0x15));
exynos_pcie_phy_writel(ep->base, 0x61, PCIE_PHY_OFFSET(0x36));
/* D0 uninit.. */
exynos_pcie_phy_writel(ep->base, 0x44, PCIE_PHY_OFFSET(0x3D));
/* 24MHz */
exynos_pcie_phy_writel(ep->base, 0x94, PCIE_PHY_OFFSET(0x8));
exynos_pcie_phy_writel(ep->base, 0xA7, PCIE_PHY_OFFSET(0x9));
exynos_pcie_phy_writel(ep->base, 0x93, PCIE_PHY_OFFSET(0xA));
exynos_pcie_phy_writel(ep->base, 0x6B, PCIE_PHY_OFFSET(0xC));
exynos_pcie_phy_writel(ep->base, 0xA5, PCIE_PHY_OFFSET(0xF));
exynos_pcie_phy_writel(ep->base, 0x34, PCIE_PHY_OFFSET(0x16));
exynos_pcie_phy_writel(ep->base, 0xA3, PCIE_PHY_OFFSET(0x17));
exynos_pcie_phy_writel(ep->base, 0xA7, PCIE_PHY_OFFSET(0x1A));
exynos_pcie_phy_writel(ep->base, 0x71, PCIE_PHY_OFFSET(0x23));
exynos_pcie_phy_writel(ep->base, 0x4C, PCIE_PHY_OFFSET(0x24));
exynos_pcie_phy_writel(ep->base, 0x0E, PCIE_PHY_OFFSET(0x26));
exynos_pcie_phy_writel(ep->base, 0x14, PCIE_PHY_OFFSET(0x7));
exynos_pcie_phy_writel(ep->base, 0x48, PCIE_PHY_OFFSET(0x43));
exynos_pcie_phy_writel(ep->base, 0x44, PCIE_PHY_OFFSET(0x44));
exynos_pcie_phy_writel(ep->base, 0x03, PCIE_PHY_OFFSET(0x45));
exynos_pcie_phy_writel(ep->base, 0xA7, PCIE_PHY_OFFSET(0x48));
exynos_pcie_phy_writel(ep->base, 0x13, PCIE_PHY_OFFSET(0x54));
exynos_pcie_phy_writel(ep->base, 0x04, PCIE_PHY_OFFSET(0x31));
exynos_pcie_phy_writel(ep->base, 0, PCIE_PHY_OFFSET(0x32));
regmap_update_bits(ep->fsysreg, PCIE_EXYNOS5433_PHY_COMMON_RESET,
PCIE_PHY_RESET, 0);
regmap_update_bits(ep->fsysreg, PCIE_EXYNOS5433_PHY_MAC_RESET,
PCIE_MAC_RESET_MASK, PCIE_MAC_RESET);
return 0;
}
static int exynos5433_pcie_phy_exit(struct phy *phy)
{
struct exynos_pcie_phy *ep = phy_get_drvdata(phy);
regmap_update_bits(ep->fsysreg, PCIE_EXYNOS5433_PHY_L1SUB_CM_CON,
PCIE_REFCLK_GATING_EN, PCIE_REFCLK_GATING_EN);
regmap_update_bits(ep->pmureg, EXYNOS5433_PMU_PCIE_PHY_OFFSET,
BIT(0), 0);
return 0;
}
static const struct phy_ops exynos5433_phy_ops = {
.init = exynos5433_pcie_phy_init,
.exit = exynos5433_pcie_phy_exit,
.owner = THIS_MODULE,
};
static const struct of_device_id exynos_pcie_phy_match[] = {
{
.compatible = "samsung,exynos5433-pcie-phy",
},
{},
};
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;
exynos_phy = devm_kzalloc(dev, sizeof(*exynos_phy), GFP_KERNEL);
if (!exynos_phy)
return -ENOMEM;
exynos_phy->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(exynos_phy->base))
return PTR_ERR(exynos_phy->base);
exynos_phy->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
"samsung,pmu-syscon");
if (IS_ERR(exynos_phy->pmureg)) {
dev_err(&pdev->dev, "PMU regmap lookup failed.\n");
return PTR_ERR(exynos_phy->pmureg);
}
exynos_phy->fsysreg = syscon_regmap_lookup_by_phandle(dev->of_node,
"samsung,fsys-sysreg");
if (IS_ERR(exynos_phy->fsysreg)) {
dev_err(&pdev->dev, "FSYS sysreg regmap lookup failed.\n");
return PTR_ERR(exynos_phy->fsysreg);
}
generic_phy = devm_phy_create(dev, dev->of_node, &exynos5433_phy_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",
.suppress_bind_attrs = true,
}
};
builtin_platform_driver(exynos_pcie_phy_driver);
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