--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * MAX3420 Device Controller driver for USB.
+ *
+ * Author: Jaswinder Singh Brar <jaswinder.singh@linaro.org>
+ * (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@linaro.org>");
+MODULE_LICENSE("GPL");
projects / platform / kernel / linux-starfive.git / commitdiff