From: Jassi Brar <jaswinder.singh@xxxxxxxxxx> The MAX3420 is USB2.0 only, UDC-over-SPI controller. This driver also supports the peripheral mode of MAX3421. Signed-off-by: Jassi Brar <jaswinder.singh@xxxxxxxxxx> --- drivers/usb/gadget/udc/Kconfig | 10 + drivers/usb/gadget/udc/Makefile | 1 + drivers/usb/gadget/udc/max3420_udc.c | 1331 ++++++++++++++++++++++++++ 3 files changed, 1342 insertions(+) create mode 100644 drivers/usb/gadget/udc/max3420_udc.c diff --git a/drivers/usb/gadget/udc/Kconfig b/drivers/usb/gadget/udc/Kconfig index 797d6ace8994..1ff82285ac7a 100644 --- a/drivers/usb/gadget/udc/Kconfig +++ b/drivers/usb/gadget/udc/Kconfig @@ -441,6 +441,16 @@ config USB_GADGET_XILINX dynamically linked module called "udc-xilinx" and force all gadget drivers to also be dynamically linked. +config USB_MAX3420_UDC + tristate "MAX3420 (USB-over-SPI) support" + depends on SPI + help + The Maxim MAX3420 chip supports USB2.0 full-speed peripheral mode. + The MAX3420 is run by SPI interface, and hence the dependency. + + To compile this driver as a module, choose M here: the module will + be called max3420_udc + config USB_TEGRA_XUDC tristate "NVIDIA Tegra Superspeed USB 3.0 Device Controller" depends on ARCH_TEGRA || COMPILE_TEST diff --git a/drivers/usb/gadget/udc/Makefile b/drivers/usb/gadget/udc/Makefile index f6777e654a8e..f5a7ce28aecd 100644 --- a/drivers/usb/gadget/udc/Makefile +++ b/drivers/usb/gadget/udc/Makefile @@ -42,3 +42,4 @@ obj-$(CONFIG_USB_GADGET_XILINX) += udc-xilinx.o obj-$(CONFIG_USB_SNP_UDC_PLAT) += snps_udc_plat.o obj-$(CONFIG_USB_ASPEED_VHUB) += aspeed-vhub/ obj-$(CONFIG_USB_BDC_UDC) += bdc/ +obj-$(CONFIG_USB_MAX3420_UDC) += max3420_udc.o diff --git a/drivers/usb/gadget/udc/max3420_udc.c b/drivers/usb/gadget/udc/max3420_udc.c new file mode 100644 index 000000000000..8fbc083b6732 --- /dev/null +++ b/drivers/usb/gadget/udc/max3420_udc.c @@ -0,0 +1,1331 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * MAX3420 Device Controller driver for USB. + * + * Author: Jaswinder Singh Brar <jaswinder.singh@xxxxxxxxxx> + * (C) Copyright 2019-2020 Linaro Ltd + * + * Based on: + * o MAX3420E datasheet + * http://datasheets.maximintegrated.com/en/ds/MAX3420E.pdf + * o MAX342{0,1}E Programming Guides + * https://pdfserv.maximintegrated.com/en/an/AN3598.pdf + * https://pdfserv.maximintegrated.com/en/an/AN3785.pdf + */ + +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/bitfield.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/of_platform.h> +#include <linux/of_irq.h> +#include <linux/prefetch.h> +#include <linux/usb/ch9.h> +#include <linux/usb/gadget.h> +#include <linux/spi/spi.h> +#include <linux/gpio/consumer.h> + +#define MAX3420_MAX_EPS 4 +#define MAX3420_EP_MAX_PACKET 64 /* Same for all Endpoints */ +#define MAX3420_EPNAME_SIZE 16 /* Buffer size for endpoint name */ + +#define MAX3420_ACKSTAT BIT(0) + +#define MAX3420_SPI_DIR_RD 0 /* read register from MAX3420 */ +#define MAX3420_SPI_DIR_WR 1 /* write register to MAX3420 */ + +/* SPI commands: */ +#define MAX3420_SPI_DIR_SHIFT 1 +#define MAX3420_SPI_REG_SHIFT 3 + +#define MAX3420_REG_EP0FIFO 0 +#define MAX3420_REG_EP1FIFO 1 +#define MAX3420_REG_EP2FIFO 2 +#define MAX3420_REG_EP3FIFO 3 +#define MAX3420_REG_SUDFIFO 4 +#define MAX3420_REG_EP0BC 5 +#define MAX3420_REG_EP1BC 6 +#define MAX3420_REG_EP2BC 7 +#define MAX3420_REG_EP3BC 8 + +#define MAX3420_REG_EPSTALLS 9 + #define ACKSTAT BIT(6) + #define STLSTAT BIT(5) + #define STLEP3IN BIT(4) + #define STLEP2IN BIT(3) + #define STLEP1OUT BIT(2) + #define STLEP0OUT BIT(1) + #define STLEP0IN BIT(0) + +#define MAX3420_REG_CLRTOGS 10 + #define EP3DISAB BIT(7) + #define EP2DISAB BIT(6) + #define EP1DISAB BIT(5) + #define CTGEP3IN BIT(4) + #define CTGEP2IN BIT(3) + #define CTGEP1OUT BIT(2) + +#define MAX3420_REG_EPIRQ 11 +#define MAX3420_REG_EPIEN 12 + #define SUDAVIRQ BIT(5) + #define IN3BAVIRQ BIT(4) + #define IN2BAVIRQ BIT(3) + #define OUT1DAVIRQ BIT(2) + #define OUT0DAVIRQ BIT(1) + #define IN0BAVIRQ BIT(0) + +#define MAX3420_REG_USBIRQ 13 +#define MAX3420_REG_USBIEN 14 + #define OSCOKIRQ BIT(0) + #define RWUDNIRQ BIT(1) + #define BUSACTIRQ BIT(2) + #define URESIRQ BIT(3) + #define SUSPIRQ BIT(4) + #define NOVBUSIRQ BIT(5) + #define VBUSIRQ BIT(6) + #define URESDNIRQ BIT(7) + +#define MAX3420_REG_USBCTL 15 + #define HOSCSTEN BIT(7) + #define VBGATE BIT(6) + #define CHIPRES BIT(5) + #define PWRDOWN BIT(4) + #define CONNECT BIT(3) + #define SIGRWU BIT(2) + +#define MAX3420_REG_CPUCTL 16 + #define IE BIT(0) + +#define MAX3420_REG_PINCTL 17 + #define EP3INAK BIT(7) + #define EP2INAK BIT(6) + #define EP0INAK BIT(5) + #define FDUPSPI BIT(4) + #define INTLEVEL BIT(3) + #define POSINT BIT(2) + #define GPXB BIT(1) + #define GPXA BIT(0) + +#define MAX3420_REG_REVISION 18 + +#define MAX3420_REG_FNADDR 19 + #define FNADDR_MASK 0x7f + +#define MAX3420_REG_IOPINS 20 +#define MAX3420_REG_IOPINS2 21 +#define MAX3420_REG_GPINIRQ 22 +#define MAX3420_REG_GPINIEN 23 +#define MAX3420_REG_GPINPOL 24 +#define MAX3420_REG_HIRQ 25 +#define MAX3420_REG_HIEN 26 +#define MAX3420_REG_MODE 27 +#define MAX3420_REG_PERADDR 28 +#define MAX3420_REG_HCTL 29 +#define MAX3420_REG_HXFR 30 +#define MAX3420_REG_HRSL 31 + +#define ENABLE_IRQ BIT(0) +#define IOPIN_UPDATE BIT(1) +#define REMOTE_WAKEUP BIT(2) +#define CONNECT_HOST GENMASK(4, 3) +#define HCONNECT (1 << 3) +#define HDISCONNECT (3 << 3) +#define UDC_START GENMASK(6, 5) +#define START (1 << 5) +#define STOP (3 << 5) +#define ENABLE_EP GENMASK(8, 7) +#define ENABLE (1 << 7) +#define DISABLE (3 << 7) +#define STALL_EP GENMASK(10, 9) +#define STALL (1 << 9) +#define UNSTALL (3 << 9) + +#define MAX3420_CMD(c) FIELD_PREP(GENMASK(7, 3), c) +#define MAX3420_SPI_CMD_RD(c) (MAX3420_CMD(c) | (0 << 1)) +#define MAX3420_SPI_CMD_WR(c) (MAX3420_CMD(c) | (1 << 1)) + +struct max3420_req { + struct usb_request usb_req; + struct list_head queue; + struct max3420_ep *ep; +}; + +struct max3420_ep { + struct usb_ep ep_usb; + struct max3420_udc *udc; + struct list_head queue; + char name[MAX3420_EPNAME_SIZE]; + unsigned int maxpacket; + spinlock_t lock; + int halted; + u32 todo; + int id; +}; + +struct max3420_udc { + struct usb_gadget gadget; + struct max3420_ep ep[MAX3420_MAX_EPS]; + struct usb_gadget_driver *driver; + struct task_struct *thread_task; + int remote_wkp, is_selfpowered; + bool vbus_active, softconnect; + struct usb_ctrlrequest setup; + struct mutex spi_bus_mutex; + struct max3420_req ep0req; + struct spi_device *spi; + struct device *dev; + spinlock_t lock; + bool suspended; + u8 ep0buf[64]; + u32 todo; +}; + +#define to_max3420_req(r) container_of((r), struct max3420_req, usb_req) +#define to_max3420_ep(e) container_of((e), struct max3420_ep, ep_usb) +#define to_udc(g) container_of((g), struct max3420_udc, gadget) + +#define DRIVER_DESC "MAX3420 USB Device-Mode Driver" +static const char driver_name[] = "max3420-udc"; + +/* Control endpoint configuration.*/ +static const struct usb_endpoint_descriptor ep0_desc = { + .bEndpointAddress = USB_DIR_OUT, + .bmAttributes = USB_ENDPOINT_XFER_CONTROL, + .wMaxPacketSize = cpu_to_le16(MAX3420_EP_MAX_PACKET), +}; + +static void spi_ack_ctrl(struct max3420_udc *udc) +{ + struct spi_device *spi = udc->spi; + struct spi_transfer transfer; + struct spi_message msg; + u8 txdata[1]; + + memset(&transfer, 0, sizeof(transfer)); + + spi_message_init(&msg); + + txdata[0] = MAX3420_ACKSTAT; + transfer.tx_buf = txdata; + transfer.len = 1; + + spi_message_add_tail(&transfer, &msg); + spi_sync(spi, &msg); +} + +static u8 spi_rd8_ack(struct max3420_udc *udc, u8 reg, int actstat) +{ + struct spi_device *spi = udc->spi; + struct spi_transfer transfer; + struct spi_message msg; + u8 txdata[2], rxdata[2]; + + memset(&transfer, 0, sizeof(transfer)); + + spi_message_init(&msg); + + txdata[0] = MAX3420_SPI_CMD_RD(reg) | (actstat ? MAX3420_ACKSTAT : 0); + transfer.tx_buf = txdata; + transfer.rx_buf = rxdata; + transfer.len = 2; + + spi_message_add_tail(&transfer, &msg); + spi_sync(spi, &msg); + + return rxdata[1]; +} + +static u8 spi_rd8(struct max3420_udc *udc, u8 reg) +{ + return spi_rd8_ack(udc, reg, 0); +} + +static void spi_wr8_ack(struct max3420_udc *udc, u8 reg, u8 val, int actstat) +{ + struct spi_device *spi = udc->spi; + struct spi_transfer transfer; + struct spi_message msg; + u8 txdata[2]; + + memset(&transfer, 0, sizeof(transfer)); + + spi_message_init(&msg); + + txdata[0] = MAX3420_SPI_CMD_WR(reg) | (actstat ? MAX3420_ACKSTAT : 0); + txdata[1] = val; + + transfer.tx_buf = txdata; + transfer.len = 2; + + spi_message_add_tail(&transfer, &msg); + spi_sync(spi, &msg); +} + +static void spi_wr8(struct max3420_udc *udc, u8 reg, u8 val) +{ + spi_wr8_ack(udc, reg, val, 0); +} + +static void spi_rd_buf(struct max3420_udc *udc, u8 reg, void *buf, u8 len) +{ + struct spi_device *spi = udc->spi; + struct spi_transfer transfer; + struct spi_message msg; + u8 local_buf[MAX3420_EP_MAX_PACKET + 1] = {}; + + memset(&transfer, 0, sizeof(transfer)); + + spi_message_init(&msg); + + local_buf[0] = MAX3420_SPI_CMD_RD(reg); + transfer.tx_buf = &local_buf[0]; + transfer.rx_buf = &local_buf[0]; + transfer.len = len + 1; + + spi_message_add_tail(&transfer, &msg); + spi_sync(spi, &msg); + + memcpy(buf, &local_buf[1], len); +} + +static void spi_wr_buf(struct max3420_udc *udc, u8 reg, void *buf, u8 len) +{ + struct spi_device *spi = udc->spi; + struct spi_transfer transfer; + struct spi_message msg; + u8 local_buf[MAX3420_EP_MAX_PACKET + 1] = {}; + + memset(&transfer, 0, sizeof(transfer)); + + spi_message_init(&msg); + + local_buf[0] = MAX3420_SPI_CMD_WR(reg); + memcpy(&local_buf[1], buf, len); + + transfer.tx_buf = local_buf; + transfer.len = len + 1; + + spi_message_add_tail(&transfer, &msg); + spi_sync(spi, &msg); +} + +static int spi_max3420_enable(struct max3420_ep *ep) +{ + struct max3420_udc *udc = ep->udc; + unsigned long flags; + u8 epdis, epien; + int todo; + + spin_lock_irqsave(&ep->lock, flags); + todo = ep->todo & ENABLE_EP; + ep->todo &= ~ENABLE_EP; + spin_unlock_irqrestore(&ep->lock, flags); + + if (!todo || ep->id == 0) + return false; + + epien = spi_rd8(udc, MAX3420_REG_EPIEN); + epdis = spi_rd8(udc, MAX3420_REG_CLRTOGS); + + if (todo == ENABLE) { + epdis &= ~BIT(ep->id + 4); + epien |= BIT(ep->id + 1); + } else { + epdis |= BIT(ep->id + 4); + epien &= ~BIT(ep->id + 1); + } + + spi_wr8(udc, MAX3420_REG_CLRTOGS, epdis); + spi_wr8(udc, MAX3420_REG_EPIEN, epien); + + return true; +} + +static int spi_max3420_stall(struct max3420_ep *ep) +{ + struct max3420_udc *udc = ep->udc; + unsigned long flags; + u8 epstalls; + int todo; + + spin_lock_irqsave(&ep->lock, flags); + todo = ep->todo & STALL_EP; + ep->todo &= ~STALL_EP; + spin_unlock_irqrestore(&ep->lock, flags); + + if (!todo || ep->id == 0) + return false; + + epstalls = spi_rd8(udc, MAX3420_REG_EPSTALLS); + if (todo == STALL) { + ep->halted = 1; + epstalls |= BIT(ep->id + 1); + } else { + u8 clrtogs; + + ep->halted = 0; + epstalls &= ~BIT(ep->id + 1); + clrtogs = spi_rd8(udc, MAX3420_REG_CLRTOGS); + clrtogs |= BIT(ep->id + 1); + spi_wr8(udc, MAX3420_REG_CLRTOGS, clrtogs); + } + spi_wr8(udc, MAX3420_REG_EPSTALLS, epstalls | ACKSTAT); + + return true; +} + +static int spi_max3420_rwkup(struct max3420_udc *udc) +{ + unsigned long flags; + int wake_remote; + u8 usbctl; + + spin_lock_irqsave(&udc->lock, flags); + wake_remote = udc->todo & REMOTE_WAKEUP; + udc->todo &= ~REMOTE_WAKEUP; + spin_unlock_irqrestore(&udc->lock, flags); + + if (!wake_remote || !udc->suspended) + return false; + + /* Set Remote-WkUp Signal*/ + usbctl = spi_rd8(udc, MAX3420_REG_USBCTL); + usbctl |= SIGRWU; + spi_wr8(udc, MAX3420_REG_USBCTL, usbctl); + + msleep_interruptible(5); + + /* Clear Remote-WkUp Signal*/ + usbctl = spi_rd8(udc, MAX3420_REG_USBCTL); + usbctl &= ~SIGRWU; + spi_wr8(udc, MAX3420_REG_USBCTL, usbctl); + + udc->suspended = false; + + return true; +} + +static void max3420_nuke(struct max3420_ep *ep, int status); +static void __max3420_stop(struct max3420_udc *udc) +{ + u8 val; + int i; + + /* clear all pending requests */ + for (i = 1; i < MAX3420_MAX_EPS; i++) + max3420_nuke(&udc->ep[i], -ECONNRESET); + + /* Disable IRQ to CPU */ + spi_wr8(udc, MAX3420_REG_CPUCTL, 0); + + val = spi_rd8(udc, MAX3420_REG_USBCTL); + val |= PWRDOWN; + if (udc->is_selfpowered) + val &= ~HOSCSTEN; + else + val |= HOSCSTEN; + spi_wr8(udc, MAX3420_REG_USBCTL, val); +} + +static void __max3420_start(struct max3420_udc *udc) +{ + u8 val; + + /* Need this delay if bus-powered, + * but even for self-powered it helps stability + */ + msleep_interruptible(250); + + /* configure SPI */ + spi_wr8(udc, MAX3420_REG_PINCTL, FDUPSPI); + + /* Chip Reset */ + spi_wr8(udc, MAX3420_REG_USBCTL, CHIPRES); + msleep_interruptible(5); + spi_wr8(udc, MAX3420_REG_USBCTL, 0); + + /* Poll for OSC to stabilize */ + while (1) { + val = spi_rd8(udc, MAX3420_REG_USBIRQ); + if (val & OSCOKIRQ) + break; + cond_resched(); + } + + /* Enable PULL-UP only when Vbus detected */ + val = spi_rd8(udc, MAX3420_REG_USBCTL); + val |= VBGATE | CONNECT; + spi_wr8(udc, MAX3420_REG_USBCTL, val); + + val = URESDNIRQ | URESIRQ; + if (udc->is_selfpowered) + val |= NOVBUSIRQ; + spi_wr8(udc, MAX3420_REG_USBIEN, val); + + /* Enable only EP0 interrupts */ + val = IN0BAVIRQ | OUT0DAVIRQ | SUDAVIRQ; + spi_wr8(udc, MAX3420_REG_EPIEN, val); + + /* Enable IRQ to CPU */ + spi_wr8(udc, MAX3420_REG_CPUCTL, IE); +} + +static int max3420_start(struct max3420_udc *udc) +{ + unsigned long flags; + int todo; + + spin_lock_irqsave(&udc->lock, flags); + todo = udc->todo & UDC_START; + udc->todo &= ~UDC_START; + spin_unlock_irqrestore(&udc->lock, flags); + + if (!todo) + return false; + + if (udc->vbus_active && udc->softconnect) + __max3420_start(udc); + else + __max3420_stop(udc); + + return true; +} + +static irqreturn_t max3420_vbus_handler(int irq, void *dev_id) +{ + struct max3420_udc *udc = dev_id; + unsigned long flags; + + spin_lock_irqsave(&udc->lock, flags); + /* its a vbus change interrupt */ + udc->vbus_active = !udc->vbus_active; + udc->todo |= UDC_START; + usb_udc_vbus_handler(&udc->gadget, udc->vbus_active); + usb_gadget_set_state(&udc->gadget, udc->vbus_active + ? USB_STATE_POWERED : USB_STATE_NOTATTACHED); + spin_unlock_irqrestore(&udc->lock, flags); + + if (udc->thread_task && + udc->thread_task->state != TASK_RUNNING) + wake_up_process(udc->thread_task); + + return IRQ_HANDLED; +} + +static irqreturn_t max3420_irq_handler(int irq, void *dev_id) +{ + struct max3420_udc *udc = dev_id; + struct spi_device *spi = udc->spi; + unsigned long flags; + + spin_lock_irqsave(&udc->lock, flags); + if ((udc->todo & ENABLE_IRQ) == 0) { + disable_irq_nosync(spi->irq); + udc->todo |= ENABLE_IRQ; + } + spin_unlock_irqrestore(&udc->lock, flags); + + if (udc->thread_task && + udc->thread_task->state != TASK_RUNNING) + wake_up_process(udc->thread_task); + + return IRQ_HANDLED; +} + +static void max3420_getstatus(struct max3420_udc *udc) +{ + struct max3420_ep *ep; + u16 status = 0; + + switch (udc->setup.bRequestType & USB_RECIP_MASK) { + case USB_RECIP_DEVICE: + /* Get device status */ + status = udc->gadget.is_selfpowered << USB_DEVICE_SELF_POWERED; + status |= (udc->remote_wkp << USB_DEVICE_REMOTE_WAKEUP); + break; + case USB_RECIP_INTERFACE: + if (udc->driver->setup(&udc->gadget, &udc->setup) < 0) + goto stall; + break; + case USB_RECIP_ENDPOINT: + ep = &udc->ep[udc->setup.wIndex & USB_ENDPOINT_NUMBER_MASK]; + if (udc->setup.wIndex & USB_DIR_IN) { + if (!ep->ep_usb.caps.dir_in) + goto stall; + } else { + if (!ep->ep_usb.caps.dir_out) + goto stall; + } + if (ep->halted) + status = 1 << USB_ENDPOINT_HALT; + break; + default: + goto stall; + } + + status = cpu_to_le16(status); + spi_wr_buf(udc, MAX3420_REG_EP0FIFO, &status, 2); + spi_wr8_ack(udc, MAX3420_REG_EP0BC, 2, 1); + return; +stall: + dev_err(udc->dev, "Can't respond to getstatus request\n"); + spi_wr8(udc, MAX3420_REG_EPSTALLS, STLEP0IN | STLEP0OUT | STLSTAT); +} + +static void max3420_set_clear_feature(struct max3420_udc *udc) +{ + struct max3420_ep *ep; + int set = udc->setup.bRequest == USB_REQ_SET_FEATURE; + unsigned long flags; + int id; + + switch (udc->setup.bRequestType) { + case USB_RECIP_DEVICE: + if (udc->setup.wValue != USB_DEVICE_REMOTE_WAKEUP) + break; + + if (udc->setup.bRequest == USB_REQ_SET_FEATURE) + udc->remote_wkp = 1; + else + udc->remote_wkp = 0; + + return spi_ack_ctrl(udc); + + case USB_RECIP_ENDPOINT: + if (udc->setup.wValue != USB_ENDPOINT_HALT) + break; + + id = udc->setup.wIndex & USB_ENDPOINT_NUMBER_MASK; + ep = &udc->ep[id]; + + spin_lock_irqsave(&ep->lock, flags); + ep->todo &= ~STALL_EP; + if (set) + ep->todo |= STALL; + else + ep->todo |= UNSTALL; + spin_unlock_irqrestore(&ep->lock, flags); + + spi_max3420_stall(ep); + return; + default: + break; + } + + dev_err(udc->dev, "Can't respond to SET/CLEAR FEATURE\n"); + spi_wr8(udc, MAX3420_REG_EPSTALLS, STLEP0IN | STLEP0OUT | STLSTAT); +} + +static void max3420_handle_setup(struct max3420_udc *udc) +{ + struct usb_ctrlrequest setup; + u8 addr; + + spi_rd_buf(udc, MAX3420_REG_SUDFIFO, (void *)&setup, 8); + + udc->setup = setup; + udc->setup.wValue = cpu_to_le16(setup.wValue); + udc->setup.wIndex = cpu_to_le16(setup.wIndex); + udc->setup.wLength = cpu_to_le16(setup.wLength); + + switch (udc->setup.bRequest) { + case USB_REQ_GET_STATUS: + /* Data+Status phase form udc */ + if ((udc->setup.bRequestType & + (USB_DIR_IN | USB_TYPE_MASK)) != + (USB_DIR_IN | USB_TYPE_STANDARD)) { + break; + } + return max3420_getstatus(udc); + case USB_REQ_SET_ADDRESS: + /* Status phase from udc */ + if (udc->setup.bRequestType != (USB_DIR_OUT | + USB_TYPE_STANDARD | USB_RECIP_DEVICE)) { + break; + } + addr = spi_rd8_ack(udc, MAX3420_REG_FNADDR, 1); + dev_dbg(udc->dev, "Assigned Address=%d\n", udc->setup.wValue); + return; + case USB_REQ_CLEAR_FEATURE: + case USB_REQ_SET_FEATURE: + /* Requests with no data phase, status phase from udc */ + if ((udc->setup.bRequestType & USB_TYPE_MASK) + != USB_TYPE_STANDARD) + break; + return max3420_set_clear_feature(udc); + default: + break; + } + + if (udc->driver->setup(&udc->gadget, &setup) < 0) { + /* Stall EP0 */ + spi_wr8(udc, MAX3420_REG_EPSTALLS, + STLEP0IN | STLEP0OUT | STLSTAT); + } +} + +static void max3420_req_done(struct max3420_req *req, int status) +{ + struct max3420_ep *ep = req->ep; + struct max3420_udc *udc = ep->udc; + + if (req->usb_req.status == -EINPROGRESS) + req->usb_req.status = status; + else + status = req->usb_req.status; + + if (status && status != -ESHUTDOWN) + dev_err(udc->dev, "%s done %p, status %d\n", + ep->ep_usb.name, req, status); + + if (req->usb_req.complete) + req->usb_req.complete(&ep->ep_usb, &req->usb_req); +} + +static int max3420_do_data(struct max3420_udc *udc, int ep_id, int in) +{ + struct max3420_ep *ep = &udc->ep[ep_id]; + struct max3420_req *req; + int done, length, psz; + void *buf; + + if (list_empty(&ep->queue)) + return false; + + req = list_first_entry(&ep->queue, struct max3420_req, queue); + buf = req->usb_req.buf + req->usb_req.actual; + + psz = ep->ep_usb.maxpacket; + length = req->usb_req.length - req->usb_req.actual; + length = min(length, psz); + + if (length == 0) { + done = 1; + goto xfer_done; + } + + done = 0; + if (in) { + prefetch(buf); + spi_wr_buf(udc, MAX3420_REG_EP0FIFO + ep_id, buf, length); + spi_wr8(udc, MAX3420_REG_EP0BC + ep_id, length); + if (length < psz) + done = 1; + } else { + psz = spi_rd8(udc, MAX3420_REG_EP0BC + ep_id); + length = min(length, psz); + prefetchw(buf); + spi_rd_buf(udc, MAX3420_REG_EP0FIFO + ep_id, buf, length); + if (length < ep->ep_usb.maxpacket) + done = 1; + } + + req->usb_req.actual += length; + + if (req->usb_req.actual == req->usb_req.length) + done = 1; + +xfer_done: + if (done) { + unsigned long flags; + + spin_lock_irqsave(&ep->lock, flags); + list_del_init(&req->queue); + spin_unlock_irqrestore(&ep->lock, flags); + + if (ep_id == 0) + spi_ack_ctrl(udc); + + max3420_req_done(req, 0); + } + + return true; +} + +static int max3420_handle_irqs(struct max3420_udc *udc) +{ + u8 epien, epirq, usbirq, usbien, reg[4]; + bool ret = false; + + spi_rd_buf(udc, MAX3420_REG_EPIRQ, reg, 4); + epirq = reg[0]; + epien = reg[1]; + usbirq = reg[2]; + usbien = reg[3]; + + usbirq &= usbien; + epirq &= epien; + + if (epirq & SUDAVIRQ) { + spi_wr8(udc, MAX3420_REG_EPIRQ, SUDAVIRQ); + max3420_handle_setup(udc); + return true; + } + + if (usbirq & VBUSIRQ) { + spi_wr8(udc, MAX3420_REG_USBIRQ, VBUSIRQ); + dev_dbg(udc->dev, "Cable plugged in\n"); + return true; + } + + if (usbirq & NOVBUSIRQ) { + spi_wr8(udc, MAX3420_REG_USBIRQ, NOVBUSIRQ); + dev_dbg(udc->dev, "Cable pulled out\n"); + return true; + } + + if (usbirq & URESIRQ) { + spi_wr8(udc, MAX3420_REG_USBIRQ, URESIRQ); + dev_dbg(udc->dev, "USB Reset - Start\n"); + return true; + } + + if (usbirq & URESDNIRQ) { + spi_wr8(udc, MAX3420_REG_USBIRQ, URESDNIRQ); + dev_dbg(udc->dev, "USB Reset - END\n"); + spi_wr8(udc, MAX3420_REG_USBIEN, URESDNIRQ | URESIRQ); + spi_wr8(udc, MAX3420_REG_EPIEN, SUDAVIRQ | IN0BAVIRQ + | OUT0DAVIRQ); + return true; + } + + if (usbirq & SUSPIRQ) { + spi_wr8(udc, MAX3420_REG_USBIRQ, SUSPIRQ); + dev_dbg(udc->dev, "USB Suspend - Enter\n"); + udc->suspended = true; + return true; + } + + if (usbirq & BUSACTIRQ) { + spi_wr8(udc, MAX3420_REG_USBIRQ, BUSACTIRQ); + dev_dbg(udc->dev, "USB Suspend - Exit\n"); + udc->suspended = false; + return true; + } + + if (usbirq & RWUDNIRQ) { + spi_wr8(udc, MAX3420_REG_USBIRQ, RWUDNIRQ); + dev_dbg(udc->dev, "Asked Host to wakeup\n"); + return true; + } + + if (usbirq & OSCOKIRQ) { + spi_wr8(udc, MAX3420_REG_USBIRQ, OSCOKIRQ); + dev_dbg(udc->dev, "Osc stabilized, start work\n"); + return true; + } + + if (epirq & OUT0DAVIRQ && max3420_do_data(udc, 0, 0)) { + spi_wr8_ack(udc, MAX3420_REG_EPIRQ, OUT0DAVIRQ, 1); + ret = true; + } + + if (epirq & IN0BAVIRQ && max3420_do_data(udc, 0, 1)) + ret = true; + + if (epirq & OUT1DAVIRQ && max3420_do_data(udc, 1, 0)) { + spi_wr8_ack(udc, MAX3420_REG_EPIRQ, OUT1DAVIRQ, 1); + ret = true; + } + + if (epirq & IN2BAVIRQ && max3420_do_data(udc, 2, 1)) + ret = true; + + if (epirq & IN3BAVIRQ && max3420_do_data(udc, 3, 1)) + ret = true; + + return ret; +} + +static int max3420_thread(void *dev_id) +{ + struct max3420_udc *udc = dev_id; + struct spi_device *spi = udc->spi; + int i, loop_again = 1; + unsigned long flags; + + while (!kthread_should_stop()) { + if (!loop_again) { + ktime_t kt = ns_to_ktime(1000 * 1000 * 250); /* 250ms */ + + set_current_state(TASK_INTERRUPTIBLE); + + spin_lock_irqsave(&udc->lock, flags); + if (udc->todo & ENABLE_IRQ) { + enable_irq(spi->irq); + udc->todo &= ~ENABLE_IRQ; + } + spin_unlock_irqrestore(&udc->lock, flags); + + schedule_hrtimeout(&kt, HRTIMER_MODE_REL); + } + loop_again = 0; + + mutex_lock(&udc->spi_bus_mutex); + + /* If bus-vbus_active and disconnected */ + if (!udc->vbus_active || !udc->softconnect) + goto loop; + + if (max3420_start(udc)) { + loop_again = 1; + goto loop; + } + + if (max3420_handle_irqs(udc)) { + loop_again = 1; + goto loop; + } + + if (spi_max3420_rwkup(udc)) { + loop_again = 1; + goto loop; + } + + max3420_do_data(udc, 0, 1); /* get done with the EP0 ZLP */ + + for (i = 1; i < MAX3420_MAX_EPS; i++) { + struct max3420_ep *ep = &udc->ep[i]; + + if (spi_max3420_enable(ep)) + loop_again = 1; + if (spi_max3420_stall(ep)) + loop_again = 1; + } +loop: + mutex_unlock(&udc->spi_bus_mutex); + } + + set_current_state(TASK_RUNNING); + dev_info(udc->dev, "SPI thread exiting"); + return 0; +} + +static int max3420_ep_set_halt(struct usb_ep *_ep, int stall) +{ + struct max3420_ep *ep = to_max3420_ep(_ep); + struct max3420_udc *udc = ep->udc; + unsigned long flags; + + spin_lock_irqsave(&ep->lock, flags); + + ep->todo &= ~STALL_EP; + if (stall) + ep->todo |= STALL; + else + ep->todo |= UNSTALL; + + spin_unlock_irqrestore(&ep->lock, flags); + + wake_up_process(udc->thread_task); + + dev_dbg(udc->dev, "%sStall %s\n", stall ? "" : "Un", ep->name); + return 0; +} + +static int __max3420_ep_enable(struct max3420_ep *ep, + const struct usb_endpoint_descriptor *desc) +{ + unsigned int maxp = usb_endpoint_maxp(desc); + unsigned long flags; + + spin_lock_irqsave(&ep->lock, flags); + ep->ep_usb.desc = desc; + ep->ep_usb.maxpacket = maxp; + + ep->todo &= ~ENABLE_EP; + ep->todo |= ENABLE; + spin_unlock_irqrestore(&ep->lock, flags); + + return 0; +} + +static int max3420_ep_enable(struct usb_ep *_ep, + const struct usb_endpoint_descriptor *desc) +{ + struct max3420_ep *ep = to_max3420_ep(_ep); + struct max3420_udc *udc = ep->udc; + + __max3420_ep_enable(ep, desc); + + wake_up_process(udc->thread_task); + + return 0; +} + +static void max3420_nuke(struct max3420_ep *ep, int status) +{ + struct max3420_req *req, *r; + unsigned long flags; + + spin_lock_irqsave(&ep->lock, flags); + + list_for_each_entry_safe(req, r, &ep->queue, queue) { + list_del_init(&req->queue); + + spin_unlock_irqrestore(&ep->lock, flags); + max3420_req_done(req, status); + spin_lock_irqsave(&ep->lock, flags); + } + + spin_unlock_irqrestore(&ep->lock, flags); +} + +static void __max3420_ep_disable(struct max3420_ep *ep) +{ + struct max3420_udc *udc = ep->udc; + unsigned long flags; + + spin_lock_irqsave(&ep->lock, flags); + + ep->ep_usb.desc = NULL; + + ep->todo &= ~ENABLE_EP; + ep->todo |= DISABLE; + + spin_unlock_irqrestore(&ep->lock, flags); + + dev_dbg(udc->dev, "Disabled %s\n", ep->name); +} + +static int max3420_ep_disable(struct usb_ep *_ep) +{ + struct max3420_ep *ep = to_max3420_ep(_ep); + struct max3420_udc *udc = ep->udc; + + max3420_nuke(ep, -ESHUTDOWN); + + __max3420_ep_disable(ep); + + wake_up_process(udc->thread_task); + + return 0; +} + +static struct usb_request *max3420_alloc_request(struct usb_ep *_ep, + gfp_t gfp_flags) +{ + struct max3420_ep *ep = to_max3420_ep(_ep); + struct max3420_req *req; + + req = kzalloc(sizeof(*req), gfp_flags); + if (!req) + return NULL; + + req->ep = ep; + + return &req->usb_req; +} + +static void max3420_free_request(struct usb_ep *_ep, struct usb_request *_req) +{ + kfree(to_max3420_req(_req)); +} + +static int max3420_ep_queue(struct usb_ep *_ep, struct usb_request *_req, + gfp_t ignored) +{ + struct max3420_req *req = to_max3420_req(_req); + struct max3420_ep *ep = to_max3420_ep(_ep); + struct max3420_udc *udc = ep->udc; + unsigned long flags; + + _req->status = -EINPROGRESS; + _req->actual = 0; + + spin_lock_irqsave(&ep->lock, flags); + list_add_tail(&req->queue, &ep->queue); + spin_unlock_irqrestore(&ep->lock, flags); + + wake_up_process(udc->thread_task); + return 0; +} + +static int max3420_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req) +{ + struct max3420_req *t, *req = to_max3420_req(_req); + struct max3420_ep *ep = to_max3420_ep(_ep); + unsigned long flags; + + spin_lock_irqsave(&ep->lock, flags); + + /* Pluck the descriptor from queue */ + list_for_each_entry(t, &ep->queue, queue) + if (t == req) { + list_del_init(&req->queue); + break; + } + + spin_unlock_irqrestore(&ep->lock, flags); + + if (t == req) + max3420_req_done(req, -ECONNRESET); + + return 0; +} + +static const struct usb_ep_ops max3420_ep_ops = { + .enable = max3420_ep_enable, + .disable = max3420_ep_disable, + .alloc_request = max3420_alloc_request, + .free_request = max3420_free_request, + .queue = max3420_ep_queue, + .dequeue = max3420_ep_dequeue, + .set_halt = max3420_ep_set_halt, +}; + +static int max3420_wakeup(struct usb_gadget *gadget) +{ + struct max3420_udc *udc = to_udc(gadget); + unsigned long flags; + int ret = -EINVAL; + + spin_lock_irqsave(&udc->lock, flags); + + /* Only if wakeup allowed by host */ + if (udc->remote_wkp) { + udc->todo |= REMOTE_WAKEUP; + ret = 0; + } + + spin_unlock_irqrestore(&udc->lock, flags); + + if (udc->thread_task && + udc->thread_task->state != TASK_RUNNING) + wake_up_process(udc->thread_task); + return ret; +} + +static int max3420_udc_start(struct usb_gadget *gadget, + struct usb_gadget_driver *driver) +{ + struct max3420_udc *udc = to_udc(gadget); + unsigned long flags; + + spin_lock_irqsave(&udc->lock, flags); + /* hook up the driver */ + driver->driver.bus = NULL; + udc->driver = driver; + udc->gadget.speed = USB_SPEED_FULL; + + udc->gadget.is_selfpowered = udc->is_selfpowered; + udc->remote_wkp = 0; + udc->softconnect = true; + udc->todo |= UDC_START; + spin_unlock_irqrestore(&udc->lock, flags); + + if (udc->thread_task && + udc->thread_task->state != TASK_RUNNING) + wake_up_process(udc->thread_task); + + return 0; +} + +static int max3420_udc_stop(struct usb_gadget *gadget) +{ + struct max3420_udc *udc = to_udc(gadget); + unsigned long flags; + + spin_lock_irqsave(&udc->lock, flags); + udc->is_selfpowered = udc->gadget.is_selfpowered; + udc->gadget.speed = USB_SPEED_UNKNOWN; + udc->driver = NULL; + udc->softconnect = false; + udc->todo |= UDC_START; + spin_unlock_irqrestore(&udc->lock, flags); + + if (udc->thread_task && + udc->thread_task->state != TASK_RUNNING) + wake_up_process(udc->thread_task); + + return 0; +} + +static const struct usb_gadget_ops max3420_udc_ops = { + .udc_start = max3420_udc_start, + .udc_stop = max3420_udc_stop, + .wakeup = max3420_wakeup, +}; + +static void max3420_eps_init(struct max3420_udc *udc) +{ + int idx; + + INIT_LIST_HEAD(&udc->gadget.ep_list); + + for (idx = 0; idx < MAX3420_MAX_EPS; idx++) { + struct max3420_ep *ep = &udc->ep[idx]; + + spin_lock_init(&ep->lock); + INIT_LIST_HEAD(&ep->queue); + + ep->udc = udc; + ep->id = idx; + ep->halted = 0; + ep->maxpacket = 0; + ep->ep_usb.name = ep->name; + ep->ep_usb.ops = &max3420_ep_ops; + usb_ep_set_maxpacket_limit(&ep->ep_usb, MAX3420_EP_MAX_PACKET); + + if (idx == 0) { /* For EP0 */ + ep->ep_usb.desc = &ep0_desc; + ep->ep_usb.maxpacket = usb_endpoint_maxp(&ep0_desc); + ep->ep_usb.caps.type_control = true; + ep->ep_usb.caps.dir_in = true; + ep->ep_usb.caps.dir_out = true; + snprintf(ep->name, MAX3420_EPNAME_SIZE, "ep0"); + continue; + } + + if (idx == 1) { /* EP1 is OUT */ + ep->ep_usb.caps.dir_in = false; + ep->ep_usb.caps.dir_out = true; + snprintf(ep->name, MAX3420_EPNAME_SIZE, "ep1-bulk-out"); + } else { /* EP2 & EP3 are IN */ + ep->ep_usb.caps.dir_in = true; + ep->ep_usb.caps.dir_out = false; + snprintf(ep->name, MAX3420_EPNAME_SIZE, + "ep%d-bulk-in", idx); + } + ep->ep_usb.caps.type_iso = false; + ep->ep_usb.caps.type_int = false; + ep->ep_usb.caps.type_bulk = true; + + list_add_tail(&ep->ep_usb.ep_list, + &udc->gadget.ep_list); + } +} + +static int max3420_probe(struct spi_device *spi) +{ + struct max3420_udc *udc; + int err, irq; + u8 reg[8]; + + if (spi->master->flags & SPI_MASTER_HALF_DUPLEX) { + dev_err(&spi->dev, "UDC needs full duplex to work\n"); + return -EINVAL; + } + + spi->mode = SPI_MODE_3; + spi->bits_per_word = 8; + + err = spi_setup(spi); + if (err) { + dev_err(&spi->dev, "Unable to setup SPI bus\n"); + return -EFAULT; + } + + udc = devm_kzalloc(&spi->dev, sizeof(*udc), GFP_KERNEL); + if (!udc) + return -ENOMEM; + + udc->spi = spi; + + udc->remote_wkp = 0; + + /* Setup gadget structure */ + udc->gadget.ops = &max3420_udc_ops; + udc->gadget.max_speed = USB_SPEED_FULL; + udc->gadget.speed = USB_SPEED_UNKNOWN; + udc->gadget.ep0 = &udc->ep[0].ep_usb; + udc->gadget.name = driver_name; + + spin_lock_init(&udc->lock); + mutex_init(&udc->spi_bus_mutex); + + udc->ep0req.ep = &udc->ep[0]; + udc->ep0req.usb_req.buf = udc->ep0buf; + INIT_LIST_HEAD(&udc->ep0req.queue); + + /* setup Endpoints */ + max3420_eps_init(udc); + + /* configure SPI */ + spi_rd_buf(udc, MAX3420_REG_EPIRQ, reg, 8); + spi_wr8(udc, MAX3420_REG_PINCTL, FDUPSPI); + + err = usb_add_gadget_udc(&spi->dev, &udc->gadget); + if (err) + return err; + + udc->dev = &udc->gadget.dev; + + spi_set_drvdata(spi, udc); + + irq = of_irq_get_byname(spi->dev.of_node, "udc"); + err = devm_request_irq(&spi->dev, irq, max3420_irq_handler, 0, + "max3420", udc); + if (err < 0) + return err; + + udc->thread_task = kthread_create(max3420_thread, udc, + "max3420-thread"); + if (IS_ERR(udc->thread_task)) + return PTR_ERR(udc->thread_task); + + irq = of_irq_get_byname(spi->dev.of_node, "vbus"); + if (irq <= 0) { /* no vbus irq implies self-powered design */ + udc->is_selfpowered = 1; + udc->vbus_active = true; + udc->todo |= UDC_START; + usb_udc_vbus_handler(&udc->gadget, udc->vbus_active); + usb_gadget_set_state(&udc->gadget, USB_STATE_POWERED); + max3420_start(udc); + } else { + udc->is_selfpowered = 0; + /* Detect current vbus status */ + spi_rd_buf(udc, MAX3420_REG_EPIRQ, reg, 8); + if (reg[7] != 0xff) + udc->vbus_active = true; + + err = devm_request_irq(&spi->dev, irq, + max3420_vbus_handler, 0, "vbus", udc); + if (err < 0) + return err; + } + + return 0; +} + +static int max3420_remove(struct spi_device *spi) +{ + struct max3420_udc *udc = spi_get_drvdata(spi); + unsigned long flags; + + usb_del_gadget_udc(&udc->gadget); + + spin_lock_irqsave(&udc->lock, flags); + + kthread_stop(udc->thread_task); + + spin_unlock_irqrestore(&udc->lock, flags); + + return 0; +} + +static const struct of_device_id max3420_udc_of_match[] = { + { .compatible = "maxim,max3420-udc"}, + { .compatible = "maxim,max3421-udc"}, + {}, +}; +MODULE_DEVICE_TABLE(of, max3420_udc_of_match); + +static struct spi_driver max3420_driver = { + .driver = { + .name = "max3420-udc", + .of_match_table = of_match_ptr(max3420_udc_of_match), + }, + .probe = max3420_probe, + .remove = max3420_remove, +}; + +module_spi_driver(max3420_driver); + +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_AUTHOR("Jassi Brar <jaswinder.singh@xxxxxxxxxx>"); +MODULE_LICENSE("GPL"); -- 2.20.1
