Messages in this thread | | | Date | Mon, 17 Jan 2022 10:28:49 +0530 | Subject | Re: [PATCH V3 4/7] soc: qcom: eud: Add driver support for Embedded USB Debugger(EUD) | From | Souradeep Chowdhury <> |
| |
On 1/7/2022 6:49 AM, Bjorn Andersson wrote: > On Tue 04 Jan 03:58 PST 2022, Souradeep Chowdhury wrote: > >> Add support for control peripheral of EUD (Embedded USB Debugger) to >> listen to events such as USB attach/detach, pet EUD to indicate software >> is functional.Reusing the platform device kobj, sysfs entry 'enable' is >> created to enable or disable EUD. >> >> To enable the eud the following needs to be done >> echo 1 > /sys/bus/platform/.../enable >> >> To disable eud, following is the command >> echo 0 > /sys/bus/platform/.../enable >> >> Signed-off-by: Souradeep Chowdhury <quic_schowdhu@quicinc.com> >> --- >> Documentation/ABI/testing/sysfs-driver-eud | 9 + >> drivers/soc/qcom/Kconfig | 10 ++ >> drivers/soc/qcom/Makefile | 1 + >> drivers/soc/qcom/qcom_eud.c | 260 +++++++++++++++++++++++++++++ >> 4 files changed, 280 insertions(+) >> create mode 100644 Documentation/ABI/testing/sysfs-driver-eud >> create mode 100644 drivers/soc/qcom/qcom_eud.c >> >> diff --git a/Documentation/ABI/testing/sysfs-driver-eud b/Documentation/ABI/testing/sysfs-driver-eud >> new file mode 100644 >> index 0000000..2381552 >> --- /dev/null >> +++ b/Documentation/ABI/testing/sysfs-driver-eud >> @@ -0,0 +1,9 @@ >> +What: /sys/bus/platform/drivers/eud/.../enable >> +Date: January 2022 >> +Contact: Souradeep Chowdhury <schowdhu@codeaurora.org> >> +Description: >> + The Enable/Disable sysfs interface for Embedded >> + USB Debugger(EUD). This enables and disables the >> + EUD based on a 1 or a 0 value. By enabling EUD, >> + the user is able to activate the mini-usb hub of >> + EUD for debug and trace capabilities. >> diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig >> index 79b568f..a4db41b 100644 >> --- a/drivers/soc/qcom/Kconfig >> +++ b/drivers/soc/qcom/Kconfig >> @@ -42,6 +42,16 @@ config QCOM_CPR >> To compile this driver as a module, choose M here: the module will >> be called qcom-cpr >> >> +config QCOM_EUD >> + tristate "QCOM Embedded USB Debugger(EUD) Driver" >> + select USB_ROLE_SWITCH >> + help >> + This module enables support for Qualcomm Technologies, Inc. >> + Embedded USB Debugger (EUD). The EUD is a control peripheral >> + which reports VBUS attach/detach events and has USB-based >> + debug and trace capabilities. On selecting m, the module name >> + that is built is qcom_eud.ko >> + >> config QCOM_GENI_SE >> tristate "QCOM GENI Serial Engine Driver" >> depends on ARCH_QCOM || COMPILE_TEST >> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile >> index ad675a6..3331a40 100644 >> --- a/drivers/soc/qcom/Makefile >> +++ b/drivers/soc/qcom/Makefile >> @@ -4,6 +4,7 @@ obj-$(CONFIG_QCOM_AOSS_QMP) += qcom_aoss.o >> obj-$(CONFIG_QCOM_GENI_SE) += qcom-geni-se.o >> obj-$(CONFIG_QCOM_COMMAND_DB) += cmd-db.o >> obj-$(CONFIG_QCOM_CPR) += cpr.o >> +obj-$(CONFIG_QCOM_EUD) += qcom_eud.o >> obj-$(CONFIG_QCOM_GSBI) += qcom_gsbi.o >> obj-$(CONFIG_QCOM_MDT_LOADER) += mdt_loader.o >> obj-$(CONFIG_QCOM_OCMEM) += ocmem.o >> diff --git a/drivers/soc/qcom/qcom_eud.c b/drivers/soc/qcom/qcom_eud.c >> new file mode 100644 >> index 0000000..7c4cc7d >> --- /dev/null >> +++ b/drivers/soc/qcom/qcom_eud.c >> @@ -0,0 +1,260 @@ >> +// SPDX-License-Identifier: GPL-2.0-only >> +/* >> + * Copyright (c) 2015-2021, The Linux Foundation. All rights reserved. >> + */ >> + >> +#include <linux/bitops.h> >> +#include <linux/delay.h> > Is this needed? Ack. > >> +#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 *eud_reg_base; > This is unnecessarily long, "base" or "eud" seems sufficient. Ack > >> + void __iomem *eud_mode_mgr2_phys_base; > "mode_mgr" Ack > >> + unsigned int int_status; >> + int eud_irq; > "irq" Ack > >> + bool enable; > "enable" is an action, but you use it to track if the state of the EUD, > i.e if it's "enabled". Ack > >> + bool usb_attach; > "attach" vs "attached" Ack > >> + > Empty line. Ack > >> +}; >> + >> +static int enable_eud(struct eud_chip *priv) >> +{ >> + writel(EUD_ENABLE, priv->eud_reg_base + EUD_REG_CSR_EUD_EN); >> + writel(EUD_INT_VBUS | EUD_INT_SAFE_MODE, >> + priv->eud_reg_base + EUD_REG_INT1_EN_MASK); >> + writel(1, priv->eud_mode_mgr2_phys_base + EUD_REG_EUD_EN2); >> + >> + return usb_role_switch_set_role(priv->role_sw, USB_ROLE_DEVICE); > When this fails, don't you want to disable the EUD again? Ack > >> +} >> + >> +static void disable_eud(struct eud_chip *priv) >> +{ >> + writel(0, priv->eud_reg_base + EUD_REG_CSR_EUD_EN); >> + writel(0, priv->eud_mode_mgr2_phys_base + 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->enable); >> +} >> + >> +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->enable = enable; >> + } 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->eud_reg_base + EUD_REG_CTL_OUT_1); >> + if (reg & EUD_INT_SAFE_MODE) >> + chip->usb_attach = true; >> + else >> + chip->usb_attach = false; > chip->usb_attach = reg & EUD_INT_SAFE_MODE; Ack >> + >> + /* set and clear vbus_int_clr[0] to clear interrupt */ >> + writel(BIT(0), chip->eud_reg_base + EUD_REG_VBUS_INT_CLR); >> + writel(0, chip->eud_reg_base + EUD_REG_VBUS_INT_CLR); > How come you do this before waking up the threaded handler? Ack > >> +} >> + >> +static void pet_eud(struct eud_chip *chip) >> +{ >> + u32 reg; >> + int ret; >> + >> + /* read sw_attach_det[0] to find attach/detach event */ > Please instead describe what this means, like: > > /* > * When the EUD_INT_PET_EUD in SW_ATTACH_DET is set, the cable has been > * disconnected and we need to detach the something because something. > */ Ack > >> + reg = readl(chip->eud_reg_base + EUD_REG_SW_ATTACH_DET); > Please drop the double space. Ack > >> + if (reg & EUD_INT_PET_EUD) { >> + /* Detach & Attach pet for EUD */ >> + writel(0, chip->eud_reg_base + EUD_REG_SW_ATTACH_DET); >> + /* Delay to make sure detach pet is done before attach pet */ >> + ret = readl_poll_timeout(chip->eud_reg_base + EUD_REG_SW_ATTACH_DET, >> + reg, (reg == 0), 1, 100); >> + if (ret) { >> + dev_err(chip->dev, "Detach pet failed\n"); >> + return; >> + } >> + >> + writel(EUD_INT_PET_EUD, chip->eud_reg_base + >> + EUD_REG_SW_ATTACH_DET); > Can you please help me see what differs between this and the write in > the else statement?
Ack. Will move this out of the if else statement.
> >> + } else { >> + /* Attach pet for EUD */ >> + writel(EUD_INT_PET_EUD, chip->eud_reg_base + >> + EUD_REG_SW_ATTACH_DET); >> + } >> +} >> + >> +static irqreturn_t handle_eud_irq(int irq, void *data) >> +{ >> + struct eud_chip *chip = data; >> + u32 reg; >> + >> + /* read status register and find out which interrupt triggered */ > That's what the next line says as well, please drop this comment. Ack > >> + reg = readl(chip->eud_reg_base + EUD_REG_INT_STATUS_1); > Please drop the double space. Ack > >> + switch (reg & EUD_INT_ALL) { > What if both of these bits are set? Won't you just end up with an > interrupt storm until someone disables the EUD again? So EUD can either be in safe mode or vbus mode , both bits will not be set together. > >> + case EUD_INT_VBUS: >> + chip->int_status = EUD_INT_VBUS; >> + usb_attach_detach(chip); >> + return IRQ_WAKE_THREAD; >> + case EUD_INT_SAFE_MODE: >> + pet_eud(chip); >> + break; > This is the only case where you break to return IRQ_HANDLED. Please be > consistent. Ack > >> + default: >> + return IRQ_NONE; >> + } >> + return IRQ_HANDLED; >> +} >> + >> +static irqreturn_t handle_eud_irq_thread(int irq, void *data) >> +{ >> + struct eud_chip *chip = data; >> + int ret; >> + >> + if (chip->int_status == EUD_INT_VBUS) { > I presume you have this here to signal that EUD_INT_VBUS was set in > EUD_REG_INT_STATUS_1 in handle_eud_irq(). > > But 1) unless this was true you wouldn't have woken up the threaded > handler and 2) you never clear int_status, so once you've received the > EUD_INT_VBUS it seems to forever be true. Ack. Will be clearing the int bits once this is done. > >> + if (chip->usb_attach) >> + 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"); >> + } >> + >> + return IRQ_HANDLED; >> +} >> + >> +static int eud_probe(struct platform_device *pdev) >> +{ >> + struct eud_chip *chip; >> + struct fwnode_handle *fwnode = pdev->dev.fwnode, *ep, *connector; >> + int ret; >> + >> + chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL); >> + if (!chip) >> + return -ENOMEM; >> + >> + chip->dev = &pdev->dev; >> + >> + ep = fwnode_graph_get_next_endpoint(fwnode, NULL); >> + if (!ep) >> + return -ENODEV; >> + >> + connector = fwnode_graph_get_remote_port_parent(ep); >> + fwnode_handle_put(ep); >> + if (!connector) >> + return -ENODEV; >> + >> + chip->role_sw = fwnode_usb_role_switch_get(connector); > Can't you just call usb_role_switch_get(&pdev->dev) to find the > "usb-role-switch", without having to traverse the fwnode_graph manually?
"usb_role_switch_get" finds the role_switch from the current or the parent node, however
in this case the usb-role-switch property is present at the parent of the connector node
which is attached to the eud node via port end point.
> >> + if (IS_ERR(chip->role_sw)) { >> + return dev_err_probe(chip->dev, PTR_ERR(chip->role_sw), >> + "failed to get role switch\n"); >> + } > Note that from now on you must usb_role_switch_put(chip->role_sw); Ack > >> + >> + chip->eud_reg_base = devm_platform_ioremap_resource(pdev, 0); >> + if (IS_ERR(chip->eud_reg_base)) >> + return PTR_ERR(chip->eud_reg_base); >> + >> + chip->eud_mode_mgr2_phys_base = devm_platform_ioremap_resource(pdev, 1); >> + if (IS_ERR(chip->eud_mode_mgr2_phys_base)) >> + return PTR_ERR(chip->eud_mode_mgr2_phys_base); >> + >> + chip->eud_irq = platform_get_irq(pdev, 0); >> + ret = devm_request_threaded_irq(&pdev->dev, chip->eud_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->eud_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->enable) >> + disable_eud(chip); >> + >> + device_init_wakeup(&pdev->dev, false); >> + disable_irq_wake(chip->eud_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, > I would prefer if you didn't indent the assignments. Ack > >> + .remove = eud_remove, >> + .driver = { >> + .name = "eud", > "qcom_eud" please. Ack > > Regards, > Bjorn > >> + .dev_groups = eud_groups, >> + .of_match_table = eud_dt_match, >> + }, >> +}; >> +module_platform_driver(eud_driver); >> + >> +MODULE_DESCRIPTION("QTI EUD driver"); >> +MODULE_LICENSE("GPL v2"); >> -- >> 2.7.4 >>
| |