diff options
Diffstat (limited to 'drivers/reset/reset-rzg2l-usbphy-ctrl.c')
| -rw-r--r-- | drivers/reset/reset-rzg2l-usbphy-ctrl.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/drivers/reset/reset-rzg2l-usbphy-ctrl.c b/drivers/reset/reset-rzg2l-usbphy-ctrl.c new file mode 100644 index 000000000..a8dde4606 --- /dev/null +++ b/drivers/reset/reset-rzg2l-usbphy-ctrl.c @@ -0,0 +1,182 @@ +// 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>"); |