diff options
Diffstat (limited to 'drivers/usb/misc/qcom_eud.c')
| -rw-r--r-- | drivers/usb/misc/qcom_eud.c | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/drivers/usb/misc/qcom_eud.c b/drivers/usb/misc/qcom_eud.c new file mode 100644 index 000000000..b7f13df00 --- /dev/null +++ b/drivers/usb/misc/qcom_eud.c @@ -0,0 +1,251 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2015-2021, The Linux Foundation. All rights reserved. + */ + +#include <linux/bitops.h> +#include <linux/err.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/sysfs.h> +#include <linux/usb/role.h> + +#define EUD_REG_INT1_EN_MASK 0x0024 +#define EUD_REG_INT_STATUS_1 0x0044 +#define EUD_REG_CTL_OUT_1 0x0074 +#define EUD_REG_VBUS_INT_CLR 0x0080 +#define EUD_REG_CSR_EUD_EN 0x1014 +#define EUD_REG_SW_ATTACH_DET 0x1018 +#define EUD_REG_EUD_EN2 0x0000 + +#define EUD_ENABLE BIT(0) +#define EUD_INT_PET_EUD BIT(0) +#define EUD_INT_VBUS BIT(2) +#define EUD_INT_SAFE_MODE BIT(4) +#define EUD_INT_ALL (EUD_INT_VBUS | EUD_INT_SAFE_MODE) + +struct eud_chip { + struct device *dev; + struct usb_role_switch *role_sw; + void __iomem *base; + void __iomem *mode_mgr; + unsigned int int_status; + int irq; + bool enabled; + bool usb_attached; +}; + +static int enable_eud(struct eud_chip *priv) +{ + writel(EUD_ENABLE, priv->base + EUD_REG_CSR_EUD_EN); + writel(EUD_INT_VBUS | EUD_INT_SAFE_MODE, + priv->base + EUD_REG_INT1_EN_MASK); + writel(1, priv->mode_mgr + EUD_REG_EUD_EN2); + + return usb_role_switch_set_role(priv->role_sw, USB_ROLE_DEVICE); +} + +static void disable_eud(struct eud_chip *priv) +{ + writel(0, priv->base + EUD_REG_CSR_EUD_EN); + writel(0, priv->mode_mgr + EUD_REG_EUD_EN2); +} + +static ssize_t enable_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct eud_chip *chip = dev_get_drvdata(dev); + + return sysfs_emit(buf, "%d\n", chip->enabled); +} + +static ssize_t enable_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct eud_chip *chip = dev_get_drvdata(dev); + bool enable; + int ret; + + if (kstrtobool(buf, &enable)) + return -EINVAL; + + if (enable) { + ret = enable_eud(chip); + if (!ret) + chip->enabled = enable; + else + disable_eud(chip); + } else { + disable_eud(chip); + } + + return count; +} + +static DEVICE_ATTR_RW(enable); + +static struct attribute *eud_attrs[] = { + &dev_attr_enable.attr, + NULL, +}; +ATTRIBUTE_GROUPS(eud); + +static void usb_attach_detach(struct eud_chip *chip) +{ + u32 reg; + + /* read ctl_out_1[4] to find USB attach or detach event */ + reg = readl(chip->base + EUD_REG_CTL_OUT_1); + chip->usb_attached = reg & EUD_INT_SAFE_MODE; +} + +static void pet_eud(struct eud_chip *chip) +{ + u32 reg; + int ret; + + /* When the EUD_INT_PET_EUD in SW_ATTACH_DET is set, the cable has been + * disconnected and we need to detach the pet to check if EUD is in safe + * mode before attaching again. + */ + reg = readl(chip->base + EUD_REG_SW_ATTACH_DET); + if (reg & EUD_INT_PET_EUD) { + /* Detach & Attach pet for EUD */ + writel(0, chip->base + EUD_REG_SW_ATTACH_DET); + /* Delay to make sure detach pet is done before attach pet */ + ret = readl_poll_timeout(chip->base + EUD_REG_SW_ATTACH_DET, + reg, (reg == 0), 1, 100); + if (ret) { + dev_err(chip->dev, "Detach pet failed\n"); + return; + } + } + /* Attach pet for EUD */ + writel(EUD_INT_PET_EUD, chip->base + EUD_REG_SW_ATTACH_DET); +} + +static irqreturn_t handle_eud_irq(int irq, void *data) +{ + struct eud_chip *chip = data; + u32 reg; + + reg = readl(chip->base + EUD_REG_INT_STATUS_1); + switch (reg & EUD_INT_ALL) { + case EUD_INT_VBUS: + usb_attach_detach(chip); + return IRQ_WAKE_THREAD; + case EUD_INT_SAFE_MODE: + pet_eud(chip); + return IRQ_HANDLED; + default: + return IRQ_NONE; + } +} + +static irqreturn_t handle_eud_irq_thread(int irq, void *data) +{ + struct eud_chip *chip = data; + int ret; + + if (chip->usb_attached) + ret = usb_role_switch_set_role(chip->role_sw, USB_ROLE_DEVICE); + else + ret = usb_role_switch_set_role(chip->role_sw, USB_ROLE_HOST); + if (ret) + dev_err(chip->dev, "failed to set role switch\n"); + + /* set and clear vbus_int_clr[0] to clear interrupt */ + writel(BIT(0), chip->base + EUD_REG_VBUS_INT_CLR); + writel(0, chip->base + EUD_REG_VBUS_INT_CLR); + + return IRQ_HANDLED; +} + +static void eud_role_switch_release(void *data) +{ + struct eud_chip *chip = data; + + usb_role_switch_put(chip->role_sw); +} + +static int eud_probe(struct platform_device *pdev) +{ + struct eud_chip *chip; + int ret; + + chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL); + if (!chip) + return -ENOMEM; + + chip->dev = &pdev->dev; + + chip->role_sw = usb_role_switch_get(&pdev->dev); + if (IS_ERR(chip->role_sw)) + return dev_err_probe(chip->dev, PTR_ERR(chip->role_sw), + "failed to get role switch\n"); + + ret = devm_add_action_or_reset(chip->dev, eud_role_switch_release, chip); + if (ret) + return dev_err_probe(chip->dev, ret, + "failed to add role switch release action\n"); + + chip->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(chip->base)) + return PTR_ERR(chip->base); + + chip->mode_mgr = devm_platform_ioremap_resource(pdev, 1); + if (IS_ERR(chip->mode_mgr)) + return PTR_ERR(chip->mode_mgr); + + chip->irq = platform_get_irq(pdev, 0); + ret = devm_request_threaded_irq(&pdev->dev, chip->irq, handle_eud_irq, + handle_eud_irq_thread, IRQF_ONESHOT, NULL, chip); + if (ret) + return dev_err_probe(chip->dev, ret, "failed to allocate irq\n"); + + enable_irq_wake(chip->irq); + + platform_set_drvdata(pdev, chip); + + return 0; +} + +static int eud_remove(struct platform_device *pdev) +{ + struct eud_chip *chip = platform_get_drvdata(pdev); + + if (chip->enabled) + disable_eud(chip); + + device_init_wakeup(&pdev->dev, false); + disable_irq_wake(chip->irq); + + return 0; +} + +static const struct of_device_id eud_dt_match[] = { + { .compatible = "qcom,sc7280-eud" }, + { } +}; +MODULE_DEVICE_TABLE(of, eud_dt_match); + +static struct platform_driver eud_driver = { + .probe = eud_probe, + .remove = eud_remove, + .driver = { + .name = "qcom_eud", + .dev_groups = eud_groups, + .of_match_table = eud_dt_match, + }, +}; +module_platform_driver(eud_driver); + +MODULE_DESCRIPTION("QTI EUD driver"); +MODULE_LICENSE("GPL v2"); |