linux/drivers/reset/reset-rzg2l-usbphy-ctrl.c
Heiner Kallweit da18980a85 reset: renesas: Check return value of reset_control_deassert()
Deasserting the reset is vital, therefore bail out in case of error.

Suggested-by: Biju Das <biju.das.jz@bp.renesas.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/b2131908-0110-006b-862f-080517f3e2d8@gmail.com
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2022-04-04 11:00:27 +02:00

183 lines
4.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Renesas RZ/G2L USBPHY control driver
*
* Copyright (C) 2021 Renesas Electronics Corporation
*/
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>
#include <linux/reset-controller.h>
#define RESET 0x000
#define RESET_SEL_PLLRESET BIT(12)
#define RESET_PLLRESET BIT(8)
#define RESET_SEL_P2RESET BIT(5)
#define RESET_SEL_P1RESET BIT(4)
#define RESET_PHYRST_2 BIT(1)
#define RESET_PHYRST_1 BIT(0)
#define PHY_RESET_PORT2 (RESET_SEL_P2RESET | RESET_PHYRST_2)
#define PHY_RESET_PORT1 (RESET_SEL_P1RESET | RESET_PHYRST_1)
#define NUM_PORTS 2
struct rzg2l_usbphy_ctrl_priv {
struct reset_controller_dev rcdev;
struct reset_control *rstc;
void __iomem *base;
spinlock_t lock;
};
#define rcdev_to_priv(x) container_of(x, struct rzg2l_usbphy_ctrl_priv, rcdev)
static int rzg2l_usbphy_ctrl_assert(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct rzg2l_usbphy_ctrl_priv *priv = rcdev_to_priv(rcdev);
u32 port_mask = PHY_RESET_PORT1 | PHY_RESET_PORT2;
void __iomem *base = priv->base;
unsigned long flags;
u32 val;
spin_lock_irqsave(&priv->lock, flags);
val = readl(base + RESET);
val |= id ? PHY_RESET_PORT2 : PHY_RESET_PORT1;
if (port_mask == (val & port_mask))
val |= RESET_PLLRESET;
writel(val, base + RESET);
spin_unlock_irqrestore(&priv->lock, flags);
return 0;
}
static int rzg2l_usbphy_ctrl_deassert(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct rzg2l_usbphy_ctrl_priv *priv = rcdev_to_priv(rcdev);
void __iomem *base = priv->base;
unsigned long flags;
u32 val;
spin_lock_irqsave(&priv->lock, flags);
val = readl(base + RESET);
val |= RESET_SEL_PLLRESET;
val &= ~(RESET_PLLRESET | (id ? PHY_RESET_PORT2 : PHY_RESET_PORT1));
writel(val, base + RESET);
spin_unlock_irqrestore(&priv->lock, flags);
return 0;
}
static int rzg2l_usbphy_ctrl_status(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct rzg2l_usbphy_ctrl_priv *priv = rcdev_to_priv(rcdev);
u32 port_mask;
port_mask = id ? PHY_RESET_PORT2 : PHY_RESET_PORT1;
return !!(readl(priv->base + RESET) & port_mask);
}
static const struct of_device_id rzg2l_usbphy_ctrl_match_table[] = {
{ .compatible = "renesas,rzg2l-usbphy-ctrl" },
{ /* Sentinel */ }
};
MODULE_DEVICE_TABLE(of, rzg2l_usbphy_ctrl_match_table);
static const struct reset_control_ops rzg2l_usbphy_ctrl_reset_ops = {
.assert = rzg2l_usbphy_ctrl_assert,
.deassert = rzg2l_usbphy_ctrl_deassert,
.status = rzg2l_usbphy_ctrl_status,
};
static int rzg2l_usbphy_ctrl_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct rzg2l_usbphy_ctrl_priv *priv;
unsigned long flags;
int error;
u32 val;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(priv->base))
return PTR_ERR(priv->base);
priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
if (IS_ERR(priv->rstc))
return dev_err_probe(dev, PTR_ERR(priv->rstc),
"failed to get reset\n");
error = reset_control_deassert(priv->rstc);
if (error)
return error;
priv->rcdev.ops = &rzg2l_usbphy_ctrl_reset_ops;
priv->rcdev.of_reset_n_cells = 1;
priv->rcdev.nr_resets = NUM_PORTS;
priv->rcdev.of_node = dev->of_node;
priv->rcdev.dev = dev;
error = devm_reset_controller_register(dev, &priv->rcdev);
if (error)
return error;
spin_lock_init(&priv->lock);
dev_set_drvdata(dev, priv);
pm_runtime_enable(&pdev->dev);
error = pm_runtime_resume_and_get(&pdev->dev);
if (error < 0) {
pm_runtime_disable(&pdev->dev);
reset_control_assert(priv->rstc);
return dev_err_probe(&pdev->dev, error, "pm_runtime_resume_and_get failed");
}
/* put pll and phy into reset state */
spin_lock_irqsave(&priv->lock, flags);
val = readl(priv->base + RESET);
val |= RESET_SEL_PLLRESET | RESET_PLLRESET | PHY_RESET_PORT2 | PHY_RESET_PORT1;
writel(val, priv->base + RESET);
spin_unlock_irqrestore(&priv->lock, flags);
return 0;
}
static int rzg2l_usbphy_ctrl_remove(struct platform_device *pdev)
{
struct rzg2l_usbphy_ctrl_priv *priv = dev_get_drvdata(&pdev->dev);
pm_runtime_put(&pdev->dev);
pm_runtime_disable(&pdev->dev);
reset_control_assert(priv->rstc);
return 0;
}
static struct platform_driver rzg2l_usbphy_ctrl_driver = {
.driver = {
.name = "rzg2l_usbphy_ctrl",
.of_match_table = rzg2l_usbphy_ctrl_match_table,
},
.probe = rzg2l_usbphy_ctrl_probe,
.remove = rzg2l_usbphy_ctrl_remove,
};
module_platform_driver(rzg2l_usbphy_ctrl_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Renesas RZ/G2L USBPHY Control");
MODULE_AUTHOR("biju.das.jz@bp.renesas.com>");