diff options
Diffstat (limited to 'drivers/usb/host/max3421-hcd.c')
| -rw-r--r-- | drivers/usb/host/max3421-hcd.c | 1972 |
1 files changed, 1972 insertions, 0 deletions
diff --git a/drivers/usb/host/max3421-hcd.c b/drivers/usb/host/max3421-hcd.c new file mode 100644 index 000000000..b875da01c --- /dev/null +++ b/drivers/usb/host/max3421-hcd.c @@ -0,0 +1,1972 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * MAX3421 Host Controller driver for USB. + * + * Author: David Mosberger-Tang <davidm@egauge.net> + * + * (C) Copyright 2014 David Mosberger-Tang <davidm@egauge.net> + * + * MAX3421 is a chip implementing a USB 2.0 Full-/Low-Speed host + * controller on a SPI bus. + * + * Based on: + * o MAX3421E datasheet + * https://datasheets.maximintegrated.com/en/ds/MAX3421E.pdf + * o MAX3421E Programming Guide + * https://www.hdl.co.jp/ftpdata/utl-001/AN3785.pdf + * o gadget/dummy_hcd.c + * For USB HCD implementation. + * o Arduino MAX3421 driver + * https://github.com/felis/USB_Host_Shield_2.0/blob/master/Usb.cpp + * + * This file is licenced under the GPL v2. + * + * Important note on worst-case (full-speed) packet size constraints + * (See USB 2.0 Section 5.6.3 and following): + * + * - control: 64 bytes + * - isochronous: 1023 bytes + * - interrupt: 64 bytes + * - bulk: 64 bytes + * + * Since the MAX3421 FIFO size is 64 bytes, we do not have to work about + * multi-FIFO writes/reads for a single USB packet *except* for isochronous + * transfers. We don't support isochronous transfers at this time, so we + * just assume that a USB packet always fits into a single FIFO buffer. + * + * NOTE: The June 2006 version of "MAX3421E Programming Guide" + * (AN3785) has conflicting info for the RCVDAVIRQ bit: + * + * The description of RCVDAVIRQ says "The CPU *must* clear + * this IRQ bit (by writing a 1 to it) before reading the + * RCVFIFO data. + * + * However, the earlier section on "Programming BULK-IN + * Transfers" says * that: + * + * After the CPU retrieves the data, it clears the + * RCVDAVIRQ bit. + * + * The December 2006 version has been corrected and it consistently + * states the second behavior is the correct one. + * + * Synchronous SPI transactions sleep so we can't perform any such + * transactions while holding a spin-lock (and/or while interrupts are + * masked). To achieve this, all SPI transactions are issued from a + * single thread (max3421_spi_thread). + */ + +#include <linux/jiffies.h> +#include <linux/module.h> +#include <linux/spi/spi.h> +#include <linux/usb.h> +#include <linux/usb/hcd.h> +#include <linux/of.h> + +#include <linux/platform_data/max3421-hcd.h> + +#define DRIVER_DESC "MAX3421 USB Host-Controller Driver" +#define DRIVER_VERSION "1.0" + +/* 11-bit counter that wraps around (USB 2.0 Section 8.3.3): */ +#define USB_MAX_FRAME_NUMBER 0x7ff +#define USB_MAX_RETRIES 3 /* # of retries before error is reported */ + +/* + * Max. # of times we're willing to retransmit a request immediately in + * resposne to a NAK. Afterwards, we fall back on trying once a frame. + */ +#define NAK_MAX_FAST_RETRANSMITS 2 + +#define POWER_BUDGET 500 /* in mA; use 8 for low-power port testing */ + +/* Port-change mask: */ +#define PORT_C_MASK ((USB_PORT_STAT_C_CONNECTION | \ + USB_PORT_STAT_C_ENABLE | \ + USB_PORT_STAT_C_SUSPEND | \ + USB_PORT_STAT_C_OVERCURRENT | \ + USB_PORT_STAT_C_RESET) << 16) + +#define MAX3421_GPOUT_COUNT 8 + +enum max3421_rh_state { + MAX3421_RH_RESET, + MAX3421_RH_SUSPENDED, + MAX3421_RH_RUNNING +}; + +enum pkt_state { + PKT_STATE_SETUP, /* waiting to send setup packet to ctrl pipe */ + PKT_STATE_TRANSFER, /* waiting to xfer transfer_buffer */ + PKT_STATE_TERMINATE /* waiting to terminate control transfer */ +}; + +enum scheduling_pass { + SCHED_PASS_PERIODIC, + SCHED_PASS_NON_PERIODIC, + SCHED_PASS_DONE +}; + +/* Bit numbers for max3421_hcd->todo: */ +enum { + ENABLE_IRQ = 0, + RESET_HCD, + RESET_PORT, + CHECK_UNLINK, + IOPIN_UPDATE +}; + +struct max3421_dma_buf { + u8 data[2]; +}; + +struct max3421_hcd { + spinlock_t lock; + + struct task_struct *spi_thread; + + enum max3421_rh_state rh_state; + /* lower 16 bits contain port status, upper 16 bits the change mask: */ + u32 port_status; + + unsigned active:1; + + struct list_head ep_list; /* list of EP's with work */ + + /* + * The following are owned by spi_thread (may be accessed by + * SPI-thread without acquiring the HCD lock: + */ + u8 rev; /* chip revision */ + u16 frame_number; + /* + * kmalloc'd buffers guaranteed to be in separate (DMA) + * cache-lines: + */ + struct max3421_dma_buf *tx; + struct max3421_dma_buf *rx; + /* + * URB we're currently processing. Must not be reset to NULL + * unless MAX3421E chip is idle: + */ + struct urb *curr_urb; + enum scheduling_pass sched_pass; + int urb_done; /* > 0 -> no errors, < 0: errno */ + size_t curr_len; + u8 hien; + u8 mode; + u8 iopins[2]; + unsigned long todo; +#ifdef DEBUG + unsigned long err_stat[16]; +#endif +}; + +struct max3421_ep { + struct usb_host_endpoint *ep; + struct list_head ep_list; + u32 naks; + u16 last_active; /* frame # this ep was last active */ + enum pkt_state pkt_state; + u8 retries; + u8 retransmit; /* packet needs retransmission */ +}; + +#define MAX3421_FIFO_SIZE 64 + +#define MAX3421_SPI_DIR_RD 0 /* read register from MAX3421 */ +#define MAX3421_SPI_DIR_WR 1 /* write register to MAX3421 */ + +/* SPI commands: */ +#define MAX3421_SPI_DIR_SHIFT 1 +#define MAX3421_SPI_REG_SHIFT 3 + +#define MAX3421_REG_RCVFIFO 1 +#define MAX3421_REG_SNDFIFO 2 +#define MAX3421_REG_SUDFIFO 4 +#define MAX3421_REG_RCVBC 6 +#define MAX3421_REG_SNDBC 7 +#define MAX3421_REG_USBIRQ 13 +#define MAX3421_REG_USBIEN 14 +#define MAX3421_REG_USBCTL 15 +#define MAX3421_REG_CPUCTL 16 +#define MAX3421_REG_PINCTL 17 +#define MAX3421_REG_REVISION 18 +#define MAX3421_REG_IOPINS1 20 +#define MAX3421_REG_IOPINS2 21 +#define MAX3421_REG_GPINIRQ 22 +#define MAX3421_REG_GPINIEN 23 +#define MAX3421_REG_GPINPOL 24 +#define MAX3421_REG_HIRQ 25 +#define MAX3421_REG_HIEN 26 +#define MAX3421_REG_MODE 27 +#define MAX3421_REG_PERADDR 28 +#define MAX3421_REG_HCTL 29 +#define MAX3421_REG_HXFR 30 +#define MAX3421_REG_HRSL 31 + +enum { + MAX3421_USBIRQ_OSCOKIRQ_BIT = 0, + MAX3421_USBIRQ_NOVBUSIRQ_BIT = 5, + MAX3421_USBIRQ_VBUSIRQ_BIT +}; + +enum { + MAX3421_CPUCTL_IE_BIT = 0, + MAX3421_CPUCTL_PULSEWID0_BIT = 6, + MAX3421_CPUCTL_PULSEWID1_BIT +}; + +enum { + MAX3421_USBCTL_PWRDOWN_BIT = 4, + MAX3421_USBCTL_CHIPRES_BIT +}; + +enum { + MAX3421_PINCTL_GPXA_BIT = 0, + MAX3421_PINCTL_GPXB_BIT, + MAX3421_PINCTL_POSINT_BIT, + MAX3421_PINCTL_INTLEVEL_BIT, + MAX3421_PINCTL_FDUPSPI_BIT, + MAX3421_PINCTL_EP0INAK_BIT, + MAX3421_PINCTL_EP2INAK_BIT, + MAX3421_PINCTL_EP3INAK_BIT, +}; + +enum { + MAX3421_HI_BUSEVENT_BIT = 0, /* bus-reset/-resume */ + MAX3421_HI_RWU_BIT, /* remote wakeup */ + MAX3421_HI_RCVDAV_BIT, /* receive FIFO data available */ + MAX3421_HI_SNDBAV_BIT, /* send buffer available */ + MAX3421_HI_SUSDN_BIT, /* suspend operation done */ + MAX3421_HI_CONDET_BIT, /* peripheral connect/disconnect */ + MAX3421_HI_FRAME_BIT, /* frame generator */ + MAX3421_HI_HXFRDN_BIT, /* host transfer done */ +}; + +enum { + MAX3421_HCTL_BUSRST_BIT = 0, + MAX3421_HCTL_FRMRST_BIT, + MAX3421_HCTL_SAMPLEBUS_BIT, + MAX3421_HCTL_SIGRSM_BIT, + MAX3421_HCTL_RCVTOG0_BIT, + MAX3421_HCTL_RCVTOG1_BIT, + MAX3421_HCTL_SNDTOG0_BIT, + MAX3421_HCTL_SNDTOG1_BIT +}; + +enum { + MAX3421_MODE_HOST_BIT = 0, + MAX3421_MODE_LOWSPEED_BIT, + MAX3421_MODE_HUBPRE_BIT, + MAX3421_MODE_SOFKAENAB_BIT, + MAX3421_MODE_SEPIRQ_BIT, + MAX3421_MODE_DELAYISO_BIT, + MAX3421_MODE_DMPULLDN_BIT, + MAX3421_MODE_DPPULLDN_BIT +}; + +enum { + MAX3421_HRSL_OK = 0, + MAX3421_HRSL_BUSY, + MAX3421_HRSL_BADREQ, + MAX3421_HRSL_UNDEF, + MAX3421_HRSL_NAK, + MAX3421_HRSL_STALL, + MAX3421_HRSL_TOGERR, + MAX3421_HRSL_WRONGPID, + MAX3421_HRSL_BADBC, + MAX3421_HRSL_PIDERR, + MAX3421_HRSL_PKTERR, + MAX3421_HRSL_CRCERR, + MAX3421_HRSL_KERR, + MAX3421_HRSL_JERR, + MAX3421_HRSL_TIMEOUT, + MAX3421_HRSL_BABBLE, + MAX3421_HRSL_RESULT_MASK = 0xf, + MAX3421_HRSL_RCVTOGRD_BIT = 4, + MAX3421_HRSL_SNDTOGRD_BIT, + MAX3421_HRSL_KSTATUS_BIT, + MAX3421_HRSL_JSTATUS_BIT +}; + +/* Return same error-codes as ohci.h:cc_to_error: */ +static const int hrsl_to_error[] = { + [MAX3421_HRSL_OK] = 0, + [MAX3421_HRSL_BUSY] = -EINVAL, + [MAX3421_HRSL_BADREQ] = -EINVAL, + [MAX3421_HRSL_UNDEF] = -EINVAL, + [MAX3421_HRSL_NAK] = -EAGAIN, + [MAX3421_HRSL_STALL] = -EPIPE, + [MAX3421_HRSL_TOGERR] = -EILSEQ, + [MAX3421_HRSL_WRONGPID] = -EPROTO, + [MAX3421_HRSL_BADBC] = -EREMOTEIO, + [MAX3421_HRSL_PIDERR] = -EPROTO, + [MAX3421_HRSL_PKTERR] = -EPROTO, + [MAX3421_HRSL_CRCERR] = -EILSEQ, + [MAX3421_HRSL_KERR] = -EIO, + [MAX3421_HRSL_JERR] = -EIO, + [MAX3421_HRSL_TIMEOUT] = -ETIME, + [MAX3421_HRSL_BABBLE] = -EOVERFLOW +}; + +/* + * See https://www.beyondlogic.org/usbnutshell/usb4.shtml#Control for a + * reasonable overview of how control transfers use the the IN/OUT + * tokens. + */ +#define MAX3421_HXFR_BULK_IN(ep) (0x00 | (ep)) /* bulk or interrupt */ +#define MAX3421_HXFR_SETUP 0x10 +#define MAX3421_HXFR_BULK_OUT(ep) (0x20 | (ep)) /* bulk or interrupt */ +#define MAX3421_HXFR_ISO_IN(ep) (0x40 | (ep)) +#define MAX3421_HXFR_ISO_OUT(ep) (0x60 | (ep)) +#define MAX3421_HXFR_HS_IN 0x80 /* handshake in */ +#define MAX3421_HXFR_HS_OUT 0xa0 /* handshake out */ + +#define field(val, bit) ((val) << (bit)) + +static inline s16 +frame_diff(u16 left, u16 right) +{ + return ((unsigned) (left - right)) % (USB_MAX_FRAME_NUMBER + 1); +} + +static inline struct max3421_hcd * +hcd_to_max3421(struct usb_hcd *hcd) +{ + return (struct max3421_hcd *) hcd->hcd_priv; +} + +static inline struct usb_hcd * +max3421_to_hcd(struct max3421_hcd *max3421_hcd) +{ + return container_of((void *) max3421_hcd, struct usb_hcd, hcd_priv); +} + +static u8 +spi_rd8(struct usb_hcd *hcd, unsigned int reg) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + struct spi_device *spi = to_spi_device(hcd->self.controller); + struct spi_transfer transfer; + struct spi_message msg; + + memset(&transfer, 0, sizeof(transfer)); + + spi_message_init(&msg); + + max3421_hcd->tx->data[0] = + (field(reg, MAX3421_SPI_REG_SHIFT) | + field(MAX3421_SPI_DIR_RD, MAX3421_SPI_DIR_SHIFT)); + + transfer.tx_buf = max3421_hcd->tx->data; + transfer.rx_buf = max3421_hcd->rx->data; + transfer.len = 2; + + spi_message_add_tail(&transfer, &msg); + spi_sync(spi, &msg); + + return max3421_hcd->rx->data[1]; +} + +static void +spi_wr8(struct usb_hcd *hcd, unsigned int reg, u8 val) +{ + struct spi_device *spi = to_spi_device(hcd->self.controller); + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + struct spi_transfer transfer; + struct spi_message msg; + + memset(&transfer, 0, sizeof(transfer)); + + spi_message_init(&msg); + + max3421_hcd->tx->data[0] = + (field(reg, MAX3421_SPI_REG_SHIFT) | + field(MAX3421_SPI_DIR_WR, MAX3421_SPI_DIR_SHIFT)); + max3421_hcd->tx->data[1] = val; + + transfer.tx_buf = max3421_hcd->tx->data; + transfer.len = 2; + + spi_message_add_tail(&transfer, &msg); + spi_sync(spi, &msg); +} + +static void +spi_rd_buf(struct usb_hcd *hcd, unsigned int reg, void *buf, size_t len) +{ + struct spi_device *spi = to_spi_device(hcd->self.controller); + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + struct spi_transfer transfer[2]; + struct spi_message msg; + + memset(transfer, 0, sizeof(transfer)); + + spi_message_init(&msg); + + max3421_hcd->tx->data[0] = + (field(reg, MAX3421_SPI_REG_SHIFT) | + field(MAX3421_SPI_DIR_RD, MAX3421_SPI_DIR_SHIFT)); + transfer[0].tx_buf = max3421_hcd->tx->data; + transfer[0].len = 1; + + transfer[1].rx_buf = buf; + transfer[1].len = len; + + spi_message_add_tail(&transfer[0], &msg); + spi_message_add_tail(&transfer[1], &msg); + spi_sync(spi, &msg); +} + +static void +spi_wr_buf(struct usb_hcd *hcd, unsigned int reg, void *buf, size_t len) +{ + struct spi_device *spi = to_spi_device(hcd->self.controller); + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + struct spi_transfer transfer[2]; + struct spi_message msg; + + memset(transfer, 0, sizeof(transfer)); + + spi_message_init(&msg); + + max3421_hcd->tx->data[0] = + (field(reg, MAX3421_SPI_REG_SHIFT) | + field(MAX3421_SPI_DIR_WR, MAX3421_SPI_DIR_SHIFT)); + + transfer[0].tx_buf = max3421_hcd->tx->data; + transfer[0].len = 1; + + transfer[1].tx_buf = buf; + transfer[1].len = len; + + spi_message_add_tail(&transfer[0], &msg); + spi_message_add_tail(&transfer[1], &msg); + spi_sync(spi, &msg); +} + +/* + * Figure out the correct setting for the LOWSPEED and HUBPRE mode + * bits. The HUBPRE bit needs to be set when MAX3421E operates at + * full speed, but it's talking to a low-speed device (i.e., through a + * hub). Setting that bit ensures that every low-speed packet is + * preceded by a full-speed PRE PID. Possible configurations: + * + * Hub speed: Device speed: => LOWSPEED bit: HUBPRE bit: + * FULL FULL => 0 0 + * FULL LOW => 1 1 + * LOW LOW => 1 0 + * LOW FULL => 1 0 + */ +static void +max3421_set_speed(struct usb_hcd *hcd, struct usb_device *dev) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + u8 mode_lowspeed, mode_hubpre, mode = max3421_hcd->mode; + + mode_lowspeed = BIT(MAX3421_MODE_LOWSPEED_BIT); + mode_hubpre = BIT(MAX3421_MODE_HUBPRE_BIT); + if (max3421_hcd->port_status & USB_PORT_STAT_LOW_SPEED) { + mode |= mode_lowspeed; + mode &= ~mode_hubpre; + } else if (dev->speed == USB_SPEED_LOW) { + mode |= mode_lowspeed | mode_hubpre; + } else { + mode &= ~(mode_lowspeed | mode_hubpre); + } + if (mode != max3421_hcd->mode) { + max3421_hcd->mode = mode; + spi_wr8(hcd, MAX3421_REG_MODE, max3421_hcd->mode); + } + +} + +/* + * Caller must NOT hold HCD spinlock. + */ +static void +max3421_set_address(struct usb_hcd *hcd, struct usb_device *dev, int epnum) +{ + int rcvtog, sndtog; + u8 hctl; + + /* setup new endpoint's toggle bits: */ + rcvtog = usb_gettoggle(dev, epnum, 0); + sndtog = usb_gettoggle(dev, epnum, 1); + hctl = (BIT(rcvtog + MAX3421_HCTL_RCVTOG0_BIT) | + BIT(sndtog + MAX3421_HCTL_SNDTOG0_BIT)); + + spi_wr8(hcd, MAX3421_REG_HCTL, hctl); + + /* + * Note: devnum for one and the same device can change during + * address-assignment so it's best to just always load the + * address whenever the end-point changed/was forced. + */ + spi_wr8(hcd, MAX3421_REG_PERADDR, dev->devnum); +} + +static int +max3421_ctrl_setup(struct usb_hcd *hcd, struct urb *urb) +{ + spi_wr_buf(hcd, MAX3421_REG_SUDFIFO, urb->setup_packet, 8); + return MAX3421_HXFR_SETUP; +} + +static int +max3421_transfer_in(struct usb_hcd *hcd, struct urb *urb) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + int epnum = usb_pipeendpoint(urb->pipe); + + max3421_hcd->curr_len = 0; + max3421_hcd->hien |= BIT(MAX3421_HI_RCVDAV_BIT); + return MAX3421_HXFR_BULK_IN(epnum); +} + +static int +max3421_transfer_out(struct usb_hcd *hcd, struct urb *urb, int fast_retransmit) +{ + struct spi_device *spi = to_spi_device(hcd->self.controller); + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + int epnum = usb_pipeendpoint(urb->pipe); + u32 max_packet; + void *src; + + src = urb->transfer_buffer + urb->actual_length; + + if (fast_retransmit) { + if (max3421_hcd->rev == 0x12) { + /* work around rev 0x12 bug: */ + spi_wr8(hcd, MAX3421_REG_SNDBC, 0); + spi_wr8(hcd, MAX3421_REG_SNDFIFO, ((u8 *) src)[0]); + spi_wr8(hcd, MAX3421_REG_SNDBC, max3421_hcd->curr_len); + } + return MAX3421_HXFR_BULK_OUT(epnum); + } + + max_packet = usb_maxpacket(urb->dev, urb->pipe, 1); + + if (max_packet > MAX3421_FIFO_SIZE) { + /* + * We do not support isochronous transfers at this + * time. + */ + dev_err(&spi->dev, + "%s: packet-size of %u too big (limit is %u bytes)", + __func__, max_packet, MAX3421_FIFO_SIZE); + max3421_hcd->urb_done = -EMSGSIZE; + return -EMSGSIZE; + } + max3421_hcd->curr_len = min((urb->transfer_buffer_length - + urb->actual_length), max_packet); + + spi_wr_buf(hcd, MAX3421_REG_SNDFIFO, src, max3421_hcd->curr_len); + spi_wr8(hcd, MAX3421_REG_SNDBC, max3421_hcd->curr_len); + return MAX3421_HXFR_BULK_OUT(epnum); +} + +/* + * Issue the next host-transfer command. + * Caller must NOT hold HCD spinlock. + */ +static void +max3421_next_transfer(struct usb_hcd *hcd, int fast_retransmit) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + struct urb *urb = max3421_hcd->curr_urb; + struct max3421_ep *max3421_ep; + int cmd = -EINVAL; + + if (!urb) + return; /* nothing to do */ + + max3421_ep = urb->ep->hcpriv; + + switch (max3421_ep->pkt_state) { + case PKT_STATE_SETUP: + cmd = max3421_ctrl_setup(hcd, urb); + break; + + case PKT_STATE_TRANSFER: + if (usb_urb_dir_in(urb)) + cmd = max3421_transfer_in(hcd, urb); + else + cmd = max3421_transfer_out(hcd, urb, fast_retransmit); + break; + + case PKT_STATE_TERMINATE: + /* + * IN transfers are terminated with HS_OUT token, + * OUT transfers with HS_IN: + */ + if (usb_urb_dir_in(urb)) + cmd = MAX3421_HXFR_HS_OUT; + else + cmd = MAX3421_HXFR_HS_IN; + break; + } + + if (cmd < 0) + return; + + /* issue the command and wait for host-xfer-done interrupt: */ + + spi_wr8(hcd, MAX3421_REG_HXFR, cmd); + max3421_hcd->hien |= BIT(MAX3421_HI_HXFRDN_BIT); +} + +/* + * Find the next URB to process and start its execution. + * + * At this time, we do not anticipate ever connecting a USB hub to the + * MAX3421 chip, so at most USB device can be connected and we can use + * a simplistic scheduler: at the start of a frame, schedule all + * periodic transfers. Once that is done, use the remainder of the + * frame to process non-periodic (bulk & control) transfers. + * + * Preconditions: + * o Caller must NOT hold HCD spinlock. + * o max3421_hcd->curr_urb MUST BE NULL. + * o MAX3421E chip must be idle. + */ +static int +max3421_select_and_start_urb(struct usb_hcd *hcd) +{ + struct spi_device *spi = to_spi_device(hcd->self.controller); + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + struct urb *urb, *curr_urb = NULL; + struct max3421_ep *max3421_ep; + int epnum; + struct usb_host_endpoint *ep; + struct list_head *pos; + unsigned long flags; + + spin_lock_irqsave(&max3421_hcd->lock, flags); + + for (; + max3421_hcd->sched_pass < SCHED_PASS_DONE; + ++max3421_hcd->sched_pass) + list_for_each(pos, &max3421_hcd->ep_list) { + urb = NULL; + max3421_ep = container_of(pos, struct max3421_ep, + ep_list); + ep = max3421_ep->ep; + + switch (usb_endpoint_type(&ep->desc)) { + case USB_ENDPOINT_XFER_ISOC: + case USB_ENDPOINT_XFER_INT: + if (max3421_hcd->sched_pass != + SCHED_PASS_PERIODIC) + continue; + break; + + case USB_ENDPOINT_XFER_CONTROL: + case USB_ENDPOINT_XFER_BULK: + if (max3421_hcd->sched_pass != + SCHED_PASS_NON_PERIODIC) + continue; + break; + } + + if (list_empty(&ep->urb_list)) + continue; /* nothing to do */ + urb = list_first_entry(&ep->urb_list, struct urb, + urb_list); + if (urb->unlinked) { + dev_dbg(&spi->dev, "%s: URB %p unlinked=%d", + __func__, urb, urb->unlinked); + max3421_hcd->curr_urb = urb; + max3421_hcd->urb_done = 1; + spin_unlock_irqrestore(&max3421_hcd->lock, + flags); + return 1; + } + + switch (usb_endpoint_type(&ep->desc)) { + case USB_ENDPOINT_XFER_CONTROL: + /* + * Allow one control transaction per + * frame per endpoint: + */ + if (frame_diff(max3421_ep->last_active, + max3421_hcd->frame_number) == 0) + continue; + break; + + case USB_ENDPOINT_XFER_BULK: + if (max3421_ep->retransmit + && (frame_diff(max3421_ep->last_active, + max3421_hcd->frame_number) + == 0)) + /* + * We already tried this EP + * during this frame and got a + * NAK or error; wait for next frame + */ + continue; + break; + + case USB_ENDPOINT_XFER_ISOC: + case USB_ENDPOINT_XFER_INT: + if (frame_diff(max3421_hcd->frame_number, + max3421_ep->last_active) + < urb->interval) + /* + * We already processed this + * end-point in the current + * frame + */ + continue; + break; + } + + /* move current ep to tail: */ + list_move_tail(pos, &max3421_hcd->ep_list); + curr_urb = urb; + goto done; + } +done: + if (!curr_urb) { + spin_unlock_irqrestore(&max3421_hcd->lock, flags); + return 0; + } + + urb = max3421_hcd->curr_urb = curr_urb; + epnum = usb_endpoint_num(&urb->ep->desc); + if (max3421_ep->retransmit) + /* restart (part of) a USB transaction: */ + max3421_ep->retransmit = 0; + else { + /* start USB transaction: */ + if (usb_endpoint_xfer_control(&ep->desc)) { + /* + * See USB 2.0 spec section 8.6.1 + * Initialization via SETUP Token: + */ + usb_settoggle(urb->dev, epnum, 0, 1); + usb_settoggle(urb->dev, epnum, 1, 1); + max3421_ep->pkt_state = PKT_STATE_SETUP; + } else + max3421_ep->pkt_state = PKT_STATE_TRANSFER; + } + + spin_unlock_irqrestore(&max3421_hcd->lock, flags); + + max3421_ep->last_active = max3421_hcd->frame_number; + max3421_set_address(hcd, urb->dev, epnum); + max3421_set_speed(hcd, urb->dev); + max3421_next_transfer(hcd, 0); + return 1; +} + +/* + * Check all endpoints for URBs that got unlinked. + * + * Caller must NOT hold HCD spinlock. + */ +static int +max3421_check_unlink(struct usb_hcd *hcd) +{ + struct spi_device *spi = to_spi_device(hcd->self.controller); + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + struct max3421_ep *max3421_ep; + struct usb_host_endpoint *ep; + struct urb *urb, *next; + unsigned long flags; + int retval = 0; + + spin_lock_irqsave(&max3421_hcd->lock, flags); + list_for_each_entry(max3421_ep, &max3421_hcd->ep_list, ep_list) { + ep = max3421_ep->ep; + list_for_each_entry_safe(urb, next, &ep->urb_list, urb_list) { + if (urb->unlinked) { + retval = 1; + dev_dbg(&spi->dev, "%s: URB %p unlinked=%d", + __func__, urb, urb->unlinked); + usb_hcd_unlink_urb_from_ep(hcd, urb); + spin_unlock_irqrestore(&max3421_hcd->lock, + flags); + usb_hcd_giveback_urb(hcd, urb, 0); + spin_lock_irqsave(&max3421_hcd->lock, flags); + } + } + } + spin_unlock_irqrestore(&max3421_hcd->lock, flags); + return retval; +} + +/* + * Caller must NOT hold HCD spinlock. + */ +static void +max3421_slow_retransmit(struct usb_hcd *hcd) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + struct urb *urb = max3421_hcd->curr_urb; + struct max3421_ep *max3421_ep; + + max3421_ep = urb->ep->hcpriv; + max3421_ep->retransmit = 1; + max3421_hcd->curr_urb = NULL; +} + +/* + * Caller must NOT hold HCD spinlock. + */ +static void +max3421_recv_data_available(struct usb_hcd *hcd) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + struct urb *urb = max3421_hcd->curr_urb; + size_t remaining, transfer_size; + u8 rcvbc; + + rcvbc = spi_rd8(hcd, MAX3421_REG_RCVBC); + + if (rcvbc > MAX3421_FIFO_SIZE) + rcvbc = MAX3421_FIFO_SIZE; + if (urb->actual_length >= urb->transfer_buffer_length) + remaining = 0; + else + remaining = urb->transfer_buffer_length - urb->actual_length; + transfer_size = rcvbc; + if (transfer_size > remaining) + transfer_size = remaining; + if (transfer_size > 0) { + void *dst = urb->transfer_buffer + urb->actual_length; + + spi_rd_buf(hcd, MAX3421_REG_RCVFIFO, dst, transfer_size); + urb->actual_length += transfer_size; + max3421_hcd->curr_len = transfer_size; + } + + /* ack the RCVDAV irq now that the FIFO has been read: */ + spi_wr8(hcd, MAX3421_REG_HIRQ, BIT(MAX3421_HI_RCVDAV_BIT)); +} + +static void +max3421_handle_error(struct usb_hcd *hcd, u8 hrsl) +{ + struct spi_device *spi = to_spi_device(hcd->self.controller); + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + u8 result_code = hrsl & MAX3421_HRSL_RESULT_MASK; + struct urb *urb = max3421_hcd->curr_urb; + struct max3421_ep *max3421_ep = urb->ep->hcpriv; + int switch_sndfifo; + + /* + * If an OUT command results in any response other than OK + * (i.e., error or NAK), we have to perform a dummy-write to + * SNDBC so the FIFO gets switched back to us. Otherwise, we + * get out of sync with the SNDFIFO double buffer. + */ + switch_sndfifo = (max3421_ep->pkt_state == PKT_STATE_TRANSFER && + usb_urb_dir_out(urb)); + + switch (result_code) { + case MAX3421_HRSL_OK: + return; /* this shouldn't happen */ + + case MAX3421_HRSL_WRONGPID: /* received wrong PID */ + case MAX3421_HRSL_BUSY: /* SIE busy */ + case MAX3421_HRSL_BADREQ: /* bad val in HXFR */ + case MAX3421_HRSL_UNDEF: /* reserved */ + case MAX3421_HRSL_KERR: /* K-state instead of response */ + case MAX3421_HRSL_JERR: /* J-state instead of response */ + /* + * packet experienced an error that we cannot recover + * from; report error + */ + max3421_hcd->urb_done = hrsl_to_error[result_code]; + dev_dbg(&spi->dev, "%s: unexpected error HRSL=0x%02x", + __func__, hrsl); + break; + + case MAX3421_HRSL_TOGERR: + if (usb_urb_dir_in(urb)) + ; /* don't do anything (device will switch toggle) */ + else { + /* flip the send toggle bit: */ + int sndtog = (hrsl >> MAX3421_HRSL_SNDTOGRD_BIT) & 1; + + sndtog ^= 1; + spi_wr8(hcd, MAX3421_REG_HCTL, + BIT(sndtog + MAX3421_HCTL_SNDTOG0_BIT)); + } + fallthrough; + case MAX3421_HRSL_BADBC: /* bad byte count */ + case MAX3421_HRSL_PIDERR: /* received PID is corrupted */ + case MAX3421_HRSL_PKTERR: /* packet error (stuff, EOP) */ + case MAX3421_HRSL_CRCERR: /* CRC error */ + case MAX3421_HRSL_BABBLE: /* device talked too long */ + case MAX3421_HRSL_TIMEOUT: + if (max3421_ep->retries++ < USB_MAX_RETRIES) + /* retry the packet again in the next frame */ + max3421_slow_retransmit(hcd); + else { + /* Based on ohci.h cc_to_err[]: */ + max3421_hcd->urb_done = hrsl_to_error[result_code]; + dev_dbg(&spi->dev, "%s: unexpected error HRSL=0x%02x", + __func__, hrsl); + } + break; + + case MAX3421_HRSL_STALL: + dev_dbg(&spi->dev, "%s: unexpected error HRSL=0x%02x", + __func__, hrsl); + max3421_hcd->urb_done = hrsl_to_error[result_code]; + break; + + case MAX3421_HRSL_NAK: + /* + * Device wasn't ready for data or has no data + * available: retry the packet again. + */ + if (max3421_ep->naks++ < NAK_MAX_FAST_RETRANSMITS) { + max3421_next_transfer(hcd, 1); + switch_sndfifo = 0; + } else + max3421_slow_retransmit(hcd); + break; + } + if (switch_sndfifo) + spi_wr8(hcd, MAX3421_REG_SNDBC, 0); +} + +/* + * Caller must NOT hold HCD spinlock. + */ +static int +max3421_transfer_in_done(struct usb_hcd *hcd, struct urb *urb) +{ + struct spi_device *spi = to_spi_device(hcd->self.controller); + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + u32 max_packet; + + if (urb->actual_length >= urb->transfer_buffer_length) + return 1; /* read is complete, so we're done */ + + /* + * USB 2.0 Section 5.3.2 Pipes: packets must be full size + * except for last one. + */ + max_packet = usb_maxpacket(urb->dev, urb->pipe, 0); + if (max_packet > MAX3421_FIFO_SIZE) { + /* + * We do not support isochronous transfers at this + * time... + */ + dev_err(&spi->dev, + "%s: packet-size of %u too big (limit is %u bytes)", + __func__, max_packet, MAX3421_FIFO_SIZE); + return -EINVAL; + } + + if (max3421_hcd->curr_len < max_packet) { + if (urb->transfer_flags & URB_SHORT_NOT_OK) { + /* + * remaining > 0 and received an + * unexpected partial packet -> + * error + */ + return -EREMOTEIO; + } else + /* short read, but it's OK */ + return 1; + } + return 0; /* not done */ +} + +/* + * Caller must NOT hold HCD spinlock. + */ +static int +max3421_transfer_out_done(struct usb_hcd *hcd, struct urb *urb) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + + urb->actual_length += max3421_hcd->curr_len; + if (urb->actual_length < urb->transfer_buffer_length) + return 0; + if (urb->transfer_flags & URB_ZERO_PACKET) { + /* + * Some hardware needs a zero-size packet at the end + * of a bulk-out transfer if the last transfer was a + * full-sized packet (i.e., such hardware use < + * max_packet as an indicator that the end of the + * packet has been reached). + */ + u32 max_packet = usb_maxpacket(urb->dev, urb->pipe, 1); + + if (max3421_hcd->curr_len == max_packet) + return 0; + } + return 1; +} + +/* + * Caller must NOT hold HCD spinlock. + */ +static void +max3421_host_transfer_done(struct usb_hcd *hcd) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + struct urb *urb = max3421_hcd->curr_urb; + struct max3421_ep *max3421_ep; + u8 result_code, hrsl; + int urb_done = 0; + + max3421_hcd->hien &= ~(BIT(MAX3421_HI_HXFRDN_BIT) | + BIT(MAX3421_HI_RCVDAV_BIT)); + + hrsl = spi_rd8(hcd, MAX3421_REG_HRSL); + result_code = hrsl & MAX3421_HRSL_RESULT_MASK; + +#ifdef DEBUG + ++max3421_hcd->err_stat[result_code]; +#endif + + max3421_ep = urb->ep->hcpriv; + + if (unlikely(result_code != MAX3421_HRSL_OK)) { + max3421_handle_error(hcd, hrsl); + return; + } + + max3421_ep->naks = 0; + max3421_ep->retries = 0; + switch (max3421_ep->pkt_state) { + + case PKT_STATE_SETUP: + if (urb->transfer_buffer_length > 0) + max3421_ep->pkt_state = PKT_STATE_TRANSFER; + else + max3421_ep->pkt_state = PKT_STATE_TERMINATE; + break; + + case PKT_STATE_TRANSFER: + if (usb_urb_dir_in(urb)) + urb_done = max3421_transfer_in_done(hcd, urb); + else + urb_done = max3421_transfer_out_done(hcd, urb); + if (urb_done > 0 && usb_pipetype(urb->pipe) == PIPE_CONTROL) { + /* + * We aren't really done - we still need to + * terminate the control transfer: + */ + max3421_hcd->urb_done = urb_done = 0; + max3421_ep->pkt_state = PKT_STATE_TERMINATE; + } + break; + + case PKT_STATE_TERMINATE: + urb_done = 1; + break; + } + + if (urb_done) + max3421_hcd->urb_done = urb_done; + else + max3421_next_transfer(hcd, 0); +} + +/* + * Caller must NOT hold HCD spinlock. + */ +static void +max3421_detect_conn(struct usb_hcd *hcd) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + unsigned int jk, have_conn = 0; + u32 old_port_status, chg; + unsigned long flags; + u8 hrsl, mode; + + hrsl = spi_rd8(hcd, MAX3421_REG_HRSL); + + jk = ((((hrsl >> MAX3421_HRSL_JSTATUS_BIT) & 1) << 0) | + (((hrsl >> MAX3421_HRSL_KSTATUS_BIT) & 1) << 1)); + + mode = max3421_hcd->mode; + + switch (jk) { + case 0x0: /* SE0: disconnect */ + /* + * Turn off SOFKAENAB bit to avoid getting interrupt + * every milli-second: + */ + mode &= ~BIT(MAX3421_MODE_SOFKAENAB_BIT); + break; + + case 0x1: /* J=0,K=1: low-speed (in full-speed or vice versa) */ + case 0x2: /* J=1,K=0: full-speed (in full-speed or vice versa) */ + if (jk == 0x2) + /* need to switch to the other speed: */ + mode ^= BIT(MAX3421_MODE_LOWSPEED_BIT); + /* turn on SOFKAENAB bit: */ + mode |= BIT(MAX3421_MODE_SOFKAENAB_BIT); + have_conn = 1; + break; + + case 0x3: /* illegal */ + break; + } + + max3421_hcd->mode = mode; + spi_wr8(hcd, MAX3421_REG_MODE, max3421_hcd->mode); + + spin_lock_irqsave(&max3421_hcd->lock, flags); + old_port_status = max3421_hcd->port_status; + if (have_conn) + max3421_hcd->port_status |= USB_PORT_STAT_CONNECTION; + else + max3421_hcd->port_status &= ~USB_PORT_STAT_CONNECTION; + if (mode & BIT(MAX3421_MODE_LOWSPEED_BIT)) + max3421_hcd->port_status |= USB_PORT_STAT_LOW_SPEED; + else + max3421_hcd->port_status &= ~USB_PORT_STAT_LOW_SPEED; + chg = (old_port_status ^ max3421_hcd->port_status); + max3421_hcd->port_status |= chg << 16; + spin_unlock_irqrestore(&max3421_hcd->lock, flags); +} + +static irqreturn_t +max3421_irq_handler(int irq, void *dev_id) +{ + struct usb_hcd *hcd = dev_id; + struct spi_device *spi = to_spi_device(hcd->self.controller); + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + + if (max3421_hcd->spi_thread && + max3421_hcd->spi_thread->state != TASK_RUNNING) + wake_up_process(max3421_hcd->spi_thread); + if (!test_and_set_bit(ENABLE_IRQ, &max3421_hcd->todo)) + disable_irq_nosync(spi->irq); + return IRQ_HANDLED; +} + +#ifdef DEBUG + +static void +dump_eps(struct usb_hcd *hcd) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + struct max3421_ep *max3421_ep; + struct usb_host_endpoint *ep; + char ubuf[512], *dp, *end; + unsigned long flags; + struct urb *urb; + int epnum, ret; + + spin_lock_irqsave(&max3421_hcd->lock, flags); + list_for_each_entry(max3421_ep, &max3421_hcd->ep_list, ep_list) { + ep = max3421_ep->ep; + + dp = ubuf; + end = dp + sizeof(ubuf); + *dp = '\0'; + list_for_each_entry(urb, &ep->urb_list, urb_list) { + ret = snprintf(dp, end - dp, " %p(%d.%s %d/%d)", urb, + usb_pipetype(urb->pipe), + usb_urb_dir_in(urb) ? "IN" : "OUT", + urb->actual_length, + urb->transfer_buffer_length); + if (ret < 0 || ret >= end - dp) + break; /* error or buffer full */ + dp += ret; + } + + epnum = usb_endpoint_num(&ep->desc); + pr_info("EP%0u %u lst %04u rtr %u nak %6u rxmt %u: %s\n", + epnum, max3421_ep->pkt_state, max3421_ep->last_active, + max3421_ep->retries, max3421_ep->naks, + max3421_ep->retransmit, ubuf); + } + spin_unlock_irqrestore(&max3421_hcd->lock, flags); +} + +#endif /* DEBUG */ + +/* Return zero if no work was performed, 1 otherwise. */ +static int +max3421_handle_irqs(struct usb_hcd *hcd) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + u32 chg, old_port_status; + unsigned long flags; + u8 hirq; + + /* + * Read and ack pending interrupts (CPU must never + * clear SNDBAV directly and RCVDAV must be cleared by + * max3421_recv_data_available()!): + */ + hirq = spi_rd8(hcd, MAX3421_REG_HIRQ); + hirq &= max3421_hcd->hien; + if (!hirq) + return 0; + + spi_wr8(hcd, MAX3421_REG_HIRQ, + hirq & ~(BIT(MAX3421_HI_SNDBAV_BIT) | + BIT(MAX3421_HI_RCVDAV_BIT))); + + if (hirq & BIT(MAX3421_HI_FRAME_BIT)) { + max3421_hcd->frame_number = ((max3421_hcd->frame_number + 1) + & USB_MAX_FRAME_NUMBER); + max3421_hcd->sched_pass = SCHED_PASS_PERIODIC; + } + + if (hirq & BIT(MAX3421_HI_RCVDAV_BIT)) + max3421_recv_data_available(hcd); + + if (hirq & BIT(MAX3421_HI_HXFRDN_BIT)) + max3421_host_transfer_done(hcd); + + if (hirq & BIT(MAX3421_HI_CONDET_BIT)) + max3421_detect_conn(hcd); + + /* + * Now process interrupts that may affect HCD state + * other than the end-points: + */ + spin_lock_irqsave(&max3421_hcd->lock, flags); + + old_port_status = max3421_hcd->port_status; + if (hirq & BIT(MAX3421_HI_BUSEVENT_BIT)) { + if (max3421_hcd->port_status & USB_PORT_STAT_RESET) { + /* BUSEVENT due to completion of Bus Reset */ + max3421_hcd->port_status &= ~USB_PORT_STAT_RESET; + max3421_hcd->port_status |= USB_PORT_STAT_ENABLE; + } else { + /* BUSEVENT due to completion of Bus Resume */ + pr_info("%s: BUSEVENT Bus Resume Done\n", __func__); + } + } + if (hirq & BIT(MAX3421_HI_RWU_BIT)) + pr_info("%s: RWU\n", __func__); + if (hirq & BIT(MAX3421_HI_SUSDN_BIT)) + pr_info("%s: SUSDN\n", __func__); + + chg = (old_port_status ^ max3421_hcd->port_status); + max3421_hcd->port_status |= chg << 16; + + spin_unlock_irqrestore(&max3421_hcd->lock, flags); + +#ifdef DEBUG + { + static unsigned long last_time; + char sbuf[16 * 16], *dp, *end; + int i; + + if (time_after(jiffies, last_time + 5*HZ)) { + dp = sbuf; + end = sbuf + sizeof(sbuf); + *dp = '\0'; + for (i = 0; i < 16; ++i) { + int ret = snprintf(dp, end - dp, " %lu", + max3421_hcd->err_stat[i]); + if (ret < 0 || ret >= end - dp) + break; /* error or buffer full */ + dp += ret; + } + pr_info("%s: hrsl_stats %s\n", __func__, sbuf); + memset(max3421_hcd->err_stat, 0, + sizeof(max3421_hcd->err_stat)); + last_time = jiffies; + + dump_eps(hcd); + } + } +#endif + return 1; +} + +static int +max3421_reset_hcd(struct usb_hcd *hcd) +{ + struct spi_device *spi = to_spi_device(hcd->self.controller); + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + int timeout; + + /* perform a chip reset and wait for OSCIRQ signal to appear: */ + spi_wr8(hcd, MAX3421_REG_USBCTL, BIT(MAX3421_USBCTL_CHIPRES_BIT)); + /* clear reset: */ + spi_wr8(hcd, MAX3421_REG_USBCTL, 0); + timeout = 1000; + while (1) { + if (spi_rd8(hcd, MAX3421_REG_USBIRQ) + & BIT(MAX3421_USBIRQ_OSCOKIRQ_BIT)) + break; + if (--timeout < 0) { + dev_err(&spi->dev, + "timed out waiting for oscillator OK signal"); + return 1; + } + cond_resched(); + } + + /* + * Turn on host mode, automatic generation of SOF packets, and + * enable pull-down registers on DM/DP: + */ + max3421_hcd->mode = (BIT(MAX3421_MODE_HOST_BIT) | + BIT(MAX3421_MODE_SOFKAENAB_BIT) | + BIT(MAX3421_MODE_DMPULLDN_BIT) | + BIT(MAX3421_MODE_DPPULLDN_BIT)); + spi_wr8(hcd, MAX3421_REG_MODE, max3421_hcd->mode); + + /* reset frame-number: */ + max3421_hcd->frame_number = USB_MAX_FRAME_NUMBER; + spi_wr8(hcd, MAX3421_REG_HCTL, BIT(MAX3421_HCTL_FRMRST_BIT)); + + /* sample the state of the D+ and D- lines */ + spi_wr8(hcd, MAX3421_REG_HCTL, BIT(MAX3421_HCTL_SAMPLEBUS_BIT)); + max3421_detect_conn(hcd); + + /* enable frame, connection-detected, and bus-event interrupts: */ + max3421_hcd->hien = (BIT(MAX3421_HI_FRAME_BIT) | + BIT(MAX3421_HI_CONDET_BIT) | + BIT(MAX3421_HI_BUSEVENT_BIT)); + spi_wr8(hcd, MAX3421_REG_HIEN, max3421_hcd->hien); + + /* enable interrupts: */ + spi_wr8(hcd, MAX3421_REG_CPUCTL, BIT(MAX3421_CPUCTL_IE_BIT)); + return 1; +} + +static int +max3421_urb_done(struct usb_hcd *hcd) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + unsigned long flags; + struct urb *urb; + int status; + + status = max3421_hcd->urb_done; + max3421_hcd->urb_done = 0; + if (status > 0) + status = 0; + urb = max3421_hcd->curr_urb; + if (urb) { + /* save the old end-points toggles: */ + u8 hrsl = spi_rd8(hcd, MAX3421_REG_HRSL); + int rcvtog = (hrsl >> MAX3421_HRSL_RCVTOGRD_BIT) & 1; + int sndtog = (hrsl >> MAX3421_HRSL_SNDTOGRD_BIT) & 1; + int epnum = usb_endpoint_num(&urb->ep->desc); + + /* no locking: HCD (i.e., we) own toggles, don't we? */ + usb_settoggle(urb->dev, epnum, 0, rcvtog); + usb_settoggle(urb->dev, epnum, 1, sndtog); + + max3421_hcd->curr_urb = NULL; + spin_lock_irqsave(&max3421_hcd->lock, flags); + usb_hcd_unlink_urb_from_ep(hcd, urb); + spin_unlock_irqrestore(&max3421_hcd->lock, flags); + + /* must be called without the HCD spinlock: */ + usb_hcd_giveback_urb(hcd, urb, status); + } + return 1; +} + +static int +max3421_spi_thread(void *dev_id) +{ + struct usb_hcd *hcd = dev_id; + struct spi_device *spi = to_spi_device(hcd->self.controller); + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + int i, i_worked = 1; + + /* set full-duplex SPI mode, low-active interrupt pin: */ + spi_wr8(hcd, MAX3421_REG_PINCTL, + (BIT(MAX3421_PINCTL_FDUPSPI_BIT) | /* full-duplex */ + BIT(MAX3421_PINCTL_INTLEVEL_BIT))); /* low-active irq */ + + while (!kthread_should_stop()) { + max3421_hcd->rev = spi_rd8(hcd, MAX3421_REG_REVISION); + if (max3421_hcd->rev == 0x12 || max3421_hcd->rev == 0x13) + break; + dev_err(&spi->dev, "bad rev 0x%02x", max3421_hcd->rev); + msleep(10000); + } + dev_info(&spi->dev, "rev 0x%x, SPI clk %dHz, bpw %u, irq %d\n", + max3421_hcd->rev, spi->max_speed_hz, spi->bits_per_word, + spi->irq); + + while (!kthread_should_stop()) { + if (!i_worked) { + /* + * We'll be waiting for wakeups from the hard + * interrupt handler, so now is a good time to + * sync our hien with the chip: + */ + spi_wr8(hcd, MAX3421_REG_HIEN, max3421_hcd->hien); + + set_current_state(TASK_INTERRUPTIBLE); + if (test_and_clear_bit(ENABLE_IRQ, &max3421_hcd->todo)) + enable_irq(spi->irq); + schedule(); + __set_current_state(TASK_RUNNING); + } + + i_worked = 0; + + if (max3421_hcd->urb_done) + i_worked |= max3421_urb_done(hcd); + else if (max3421_handle_irqs(hcd)) + i_worked = 1; + else if (!max3421_hcd->curr_urb) + i_worked |= max3421_select_and_start_urb(hcd); + + if (test_and_clear_bit(RESET_HCD, &max3421_hcd->todo)) + /* reset the HCD: */ + i_worked |= max3421_reset_hcd(hcd); + if (test_and_clear_bit(RESET_PORT, &max3421_hcd->todo)) { + /* perform a USB bus reset: */ + spi_wr8(hcd, MAX3421_REG_HCTL, + BIT(MAX3421_HCTL_BUSRST_BIT)); + i_worked = 1; + } + if (test_and_clear_bit(CHECK_UNLINK, &max3421_hcd->todo)) + i_worked |= max3421_check_unlink(hcd); + if (test_and_clear_bit(IOPIN_UPDATE, &max3421_hcd->todo)) { + /* + * IOPINS1/IOPINS2 do not auto-increment, so we can't + * use spi_wr_buf(). + */ + for (i = 0; i < ARRAY_SIZE(max3421_hcd->iopins); ++i) { + u8 val = spi_rd8(hcd, MAX3421_REG_IOPINS1); + + val = ((val & 0xf0) | + (max3421_hcd->iopins[i] & 0x0f)); + spi_wr8(hcd, MAX3421_REG_IOPINS1 + i, val); + max3421_hcd->iopins[i] = val; + } + i_worked = 1; + } + } + set_current_state(TASK_RUNNING); + dev_info(&spi->dev, "SPI thread exiting"); + return 0; +} + +static int +max3421_reset_port(struct usb_hcd *hcd) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + + max3421_hcd->port_status &= ~(USB_PORT_STAT_ENABLE | + USB_PORT_STAT_LOW_SPEED); + max3421_hcd->port_status |= USB_PORT_STAT_RESET; + set_bit(RESET_PORT, &max3421_hcd->todo); + wake_up_process(max3421_hcd->spi_thread); + return 0; +} + +static int +max3421_reset(struct usb_hcd *hcd) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + + hcd->self.sg_tablesize = 0; + hcd->speed = HCD_USB2; + hcd->self.root_hub->speed = USB_SPEED_FULL; + set_bit(RESET_HCD, &max3421_hcd->todo); + wake_up_process(max3421_hcd->spi_thread); + return 0; +} + +static int +max3421_start(struct usb_hcd *hcd) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + + spin_lock_init(&max3421_hcd->lock); + max3421_hcd->rh_state = MAX3421_RH_RUNNING; + + INIT_LIST_HEAD(&max3421_hcd->ep_list); + + hcd->power_budget = POWER_BUDGET; + hcd->state = HC_STATE_RUNNING; + hcd->uses_new_polling = 1; + return 0; +} + +static void +max3421_stop(struct usb_hcd *hcd) +{ +} + +static int +max3421_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags) +{ + struct spi_device *spi = to_spi_device(hcd->self.controller); + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + struct max3421_ep *max3421_ep; + unsigned long flags; + int retval; + + switch (usb_pipetype(urb->pipe)) { + case PIPE_INTERRUPT: + case PIPE_ISOCHRONOUS: + if (urb->interval < 0) { + dev_err(&spi->dev, + "%s: interval=%d for intr-/iso-pipe; expected > 0\n", + __func__, urb->interval); + return -EINVAL; + } + default: + break; + } + + spin_lock_irqsave(&max3421_hcd->lock, flags); + + max3421_ep = urb->ep->hcpriv; + if (!max3421_ep) { + /* gets freed in max3421_endpoint_disable: */ + max3421_ep = kzalloc(sizeof(struct max3421_ep), GFP_ATOMIC); + if (!max3421_ep) { + retval = -ENOMEM; + goto out; + } + max3421_ep->ep = urb->ep; + max3421_ep->last_active = max3421_hcd->frame_number; + urb->ep->hcpriv = max3421_ep; + + list_add_tail(&max3421_ep->ep_list, &max3421_hcd->ep_list); + } + + retval = usb_hcd_link_urb_to_ep(hcd, urb); + if (retval == 0) { + /* Since we added to the queue, restart scheduling: */ + max3421_hcd->sched_pass = SCHED_PASS_PERIODIC; + wake_up_process(max3421_hcd->spi_thread); + } + +out: + spin_unlock_irqrestore(&max3421_hcd->lock, flags); + return retval; +} + +static int +max3421_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + unsigned long flags; + int retval; + + spin_lock_irqsave(&max3421_hcd->lock, flags); + + /* + * This will set urb->unlinked which in turn causes the entry + * to be dropped at the next opportunity. + */ + retval = usb_hcd_check_unlink_urb(hcd, urb, status); + if (retval == 0) { + set_bit(CHECK_UNLINK, &max3421_hcd->todo); + wake_up_process(max3421_hcd->spi_thread); + } + spin_unlock_irqrestore(&max3421_hcd->lock, flags); + return retval; +} + +static void +max3421_endpoint_disable(struct usb_hcd *hcd, struct usb_host_endpoint *ep) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + unsigned long flags; + + spin_lock_irqsave(&max3421_hcd->lock, flags); + + if (ep->hcpriv) { + struct max3421_ep *max3421_ep = ep->hcpriv; + + /* remove myself from the ep_list: */ + if (!list_empty(&max3421_ep->ep_list)) + list_del(&max3421_ep->ep_list); + kfree(max3421_ep); + ep->hcpriv = NULL; + } + + spin_unlock_irqrestore(&max3421_hcd->lock, flags); +} + +static int +max3421_get_frame_number(struct usb_hcd *hcd) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + return max3421_hcd->frame_number; +} + +/* + * Should return a non-zero value when any port is undergoing a resume + * transition while the root hub is suspended. + */ +static int +max3421_hub_status_data(struct usb_hcd *hcd, char *buf) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + unsigned long flags; + int retval = 0; + + spin_lock_irqsave(&max3421_hcd->lock, flags); + if (!HCD_HW_ACCESSIBLE(hcd)) + goto done; + + *buf = 0; + if ((max3421_hcd->port_status & PORT_C_MASK) != 0) { + *buf = (1 << 1); /* a hub over-current condition exists */ + dev_dbg(hcd->self.controller, + "port status 0x%08x has changes\n", + max3421_hcd->port_status); + retval = 1; + if (max3421_hcd->rh_state == MAX3421_RH_SUSPENDED) + usb_hcd_resume_root_hub(hcd); + } +done: + spin_unlock_irqrestore(&max3421_hcd->lock, flags); + return retval; +} + +static inline void +hub_descriptor(struct usb_hub_descriptor *desc) +{ + memset(desc, 0, sizeof(*desc)); + /* + * See Table 11-13: Hub Descriptor in USB 2.0 spec. + */ + desc->bDescriptorType = USB_DT_HUB; /* hub descriptor */ + desc->bDescLength = 9; + desc->wHubCharacteristics = cpu_to_le16(HUB_CHAR_INDV_PORT_LPSM | + HUB_CHAR_COMMON_OCPM); + desc->bNbrPorts = 1; +} + +/* + * Set the MAX3421E general-purpose output with number PIN_NUMBER to + * VALUE (0 or 1). PIN_NUMBER may be in the range from 1-8. For + * any other value, this function acts as a no-op. + */ +static void +max3421_gpout_set_value(struct usb_hcd *hcd, u8 pin_number, u8 value) +{ + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + u8 mask, idx; + + --pin_number; + if (pin_number >= MAX3421_GPOUT_COUNT) + return; + + mask = 1u << (pin_number % 4); + idx = pin_number / 4; + + if (value) + max3421_hcd->iopins[idx] |= mask; + else + max3421_hcd->iopins[idx] &= ~mask; + set_bit(IOPIN_UPDATE, &max3421_hcd->todo); + wake_up_process(max3421_hcd->spi_thread); +} + +static int +max3421_hub_control(struct usb_hcd *hcd, u16 type_req, u16 value, u16 index, + char *buf, u16 length) +{ + struct spi_device *spi = to_spi_device(hcd->self.controller); + struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); + struct max3421_hcd_platform_data *pdata; + unsigned long flags; + int retval = 0; + + pdata = spi->dev.platform_data; + + spin_lock_irqsave(&max3421_hcd->lock, flags); + + switch (type_req) { + case ClearHubFeature: + break; + case ClearPortFeature: + switch (value) { + case USB_PORT_FEAT_SUSPEND: + break; + case USB_PORT_FEAT_POWER: + dev_dbg(hcd->self.controller, "power-off\n"); + max3421_gpout_set_value(hcd, pdata->vbus_gpout, + !pdata->vbus_active_level); + fallthrough; + default: + max3421_hcd->port_status &= ~(1 << value); + } + break; + case GetHubDescriptor: + hub_descriptor((struct usb_hub_descriptor *) buf); + break; + + case DeviceRequest | USB_REQ_GET_DESCRIPTOR: + case GetPortErrorCount: + case SetHubDepth: + /* USB3 only */ + goto error; + + case GetHubStatus: + *(__le32 *) buf = cpu_to_le32(0); + break; + + case GetPortStatus: + if (index != 1) { + retval = -EPIPE; + goto error; + } + ((__le16 *) buf)[0] = cpu_to_le16(max3421_hcd->port_status); + ((__le16 *) buf)[1] = + cpu_to_le16(max3421_hcd->port_status >> 16); + break; + + case SetHubFeature: + retval = -EPIPE; + break; + + case SetPortFeature: + switch (value) { + case USB_PORT_FEAT_LINK_STATE: + case USB_PORT_FEAT_U1_TIMEOUT: + case USB_PORT_FEAT_U2_TIMEOUT: + case USB_PORT_FEAT_BH_PORT_RESET: + goto error; + case USB_PORT_FEAT_SUSPEND: + if (max3421_hcd->active) + max3421_hcd->port_status |= + USB_PORT_STAT_SUSPEND; + break; + case USB_PORT_FEAT_POWER: + dev_dbg(hcd->self.controller, "power-on\n"); + max3421_hcd->port_status |= USB_PORT_STAT_POWER; + max3421_gpout_set_value(hcd, pdata->vbus_gpout, + pdata->vbus_active_level); + break; + case USB_PORT_FEAT_RESET: + max3421_reset_port(hcd); + fallthrough; + default: + if ((max3421_hcd->port_status & USB_PORT_STAT_POWER) + != 0) + max3421_hcd->port_status |= (1 << value); + } + break; + + default: + dev_dbg(hcd->self.controller, + "hub control req%04x v%04x i%04x l%d\n", + type_req, value, index, length); +error: /* "protocol stall" on error */ + retval = -EPIPE; + } + + spin_unlock_irqrestore(&max3421_hcd->lock, flags); + return retval; +} + +static int +max3421_bus_suspend(struct usb_hcd *hcd) +{ + return -1; +} + +static int +max3421_bus_resume(struct usb_hcd *hcd) +{ + return -1; +} + +static const struct hc_driver max3421_hcd_desc = { + .description = "max3421", + .product_desc = DRIVER_DESC, + .hcd_priv_size = sizeof(struct max3421_hcd), + .flags = HCD_USB11, + .reset = max3421_reset, + .start = max3421_start, + .stop = max3421_stop, + .get_frame_number = max3421_get_frame_number, + .urb_enqueue = max3421_urb_enqueue, + .urb_dequeue = max3421_urb_dequeue, + .endpoint_disable = max3421_endpoint_disable, + .hub_status_data = max3421_hub_status_data, + .hub_control = max3421_hub_control, + .bus_suspend = max3421_bus_suspend, + .bus_resume = max3421_bus_resume, +}; + +static int +max3421_of_vbus_en_pin(struct device *dev, struct max3421_hcd_platform_data *pdata) +{ + int retval; + uint32_t value[2]; + + if (!pdata) + return -EINVAL; + + retval = of_property_read_u32_array(dev->of_node, "maxim,vbus-en-pin", value, 2); + if (retval) { + dev_err(dev, "device tree node property 'maxim,vbus-en-pin' is missing\n"); + return retval; + } + dev_info(dev, "property 'maxim,vbus-en-pin' value is <%d %d>\n", value[0], value[1]); + + pdata->vbus_gpout = value[0]; + pdata->vbus_active_level = value[1]; + + return 0; +} + +static int +max3421_probe(struct spi_device *spi) +{ + struct device *dev = &spi->dev; + struct max3421_hcd *max3421_hcd; + struct usb_hcd *hcd = NULL; + struct max3421_hcd_platform_data *pdata = NULL; + int retval; + + if (spi_setup(spi) < 0) { + dev_err(&spi->dev, "Unable to setup SPI bus"); + return -EFAULT; + } + + if (!spi->irq) { + dev_err(dev, "Failed to get SPI IRQ"); + return -EFAULT; + } + + if (IS_ENABLED(CONFIG_OF) && dev->of_node) { + pdata = devm_kzalloc(&spi->dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) { + retval = -ENOMEM; + goto error; + } + retval = max3421_of_vbus_en_pin(dev, pdata); + if (retval) + goto error; + + spi->dev.platform_data = pdata; + } + + pdata = spi->dev.platform_data; + if (!pdata) { + dev_err(&spi->dev, "driver configuration data is not provided\n"); + retval = -EFAULT; + goto error; + } + if (pdata->vbus_active_level > 1) { + dev_err(&spi->dev, "vbus active level value %d is out of range (0/1)\n", pdata->vbus_active_level); + retval = -EINVAL; + goto error; + } + if (pdata->vbus_gpout < 1 || pdata->vbus_gpout > MAX3421_GPOUT_COUNT) { + dev_err(&spi->dev, "vbus gpout value %d is out of range (1..8)\n", pdata->vbus_gpout); + retval = -EINVAL; + goto error; + } + + retval = -ENOMEM; + hcd = usb_create_hcd(&max3421_hcd_desc, &spi->dev, + dev_name(&spi->dev)); + if (!hcd) { + dev_err(&spi->dev, "failed to create HCD structure\n"); + goto error; + } + set_bit(HCD_FLAG_POLL_RH, &hcd->flags); + max3421_hcd = hcd_to_max3421(hcd); + INIT_LIST_HEAD(&max3421_hcd->ep_list); + spi_set_drvdata(spi, max3421_hcd); + + max3421_hcd->tx = kmalloc(sizeof(*max3421_hcd->tx), GFP_KERNEL); + if (!max3421_hcd->tx) + goto error; + max3421_hcd->rx = kmalloc(sizeof(*max3421_hcd->rx), GFP_KERNEL); + if (!max3421_hcd->rx) + goto error; + + max3421_hcd->spi_thread = kthread_run(max3421_spi_thread, hcd, + "max3421_spi_thread"); + if (max3421_hcd->spi_thread == ERR_PTR(-ENOMEM)) { + dev_err(&spi->dev, + "failed to create SPI thread (out of memory)\n"); + goto error; + } + + retval = usb_add_hcd(hcd, 0, 0); + if (retval) { + dev_err(&spi->dev, "failed to add HCD\n"); + goto error; + } + + retval = request_irq(spi->irq, max3421_irq_handler, + IRQF_TRIGGER_LOW, "max3421", hcd); + if (retval < 0) { + dev_err(&spi->dev, "failed to request irq %d\n", spi->irq); + goto error; + } + return 0; + +error: + if (IS_ENABLED(CONFIG_OF) && dev->of_node && pdata) { + devm_kfree(&spi->dev, pdata); + spi->dev.platform_data = NULL; + } + + if (hcd) { + kfree(max3421_hcd->tx); + kfree(max3421_hcd->rx); + if (max3421_hcd->spi_thread) + kthread_stop(max3421_hcd->spi_thread); + usb_put_hcd(hcd); + } + return retval; +} + +static int +max3421_remove(struct spi_device *spi) +{ + struct max3421_hcd *max3421_hcd; + struct usb_hcd *hcd; + unsigned long flags; + + max3421_hcd = spi_get_drvdata(spi); + hcd = max3421_to_hcd(max3421_hcd); + + usb_remove_hcd(hcd); + + spin_lock_irqsave(&max3421_hcd->lock, flags); + + kthread_stop(max3421_hcd->spi_thread); + + spin_unlock_irqrestore(&max3421_hcd->lock, flags); + + free_irq(spi->irq, hcd); + + usb_put_hcd(hcd); + return 0; +} + +static const struct of_device_id max3421_of_match_table[] = { + { .compatible = "maxim,max3421", }, + {}, +}; +MODULE_DEVICE_TABLE(of, max3421_of_match_table); + +static struct spi_driver max3421_driver = { + .probe = max3421_probe, + .remove = max3421_remove, + .driver = { + .name = "max3421-hcd", + .of_match_table = of_match_ptr(max3421_of_match_table), + }, +}; + +module_spi_driver(max3421_driver); + +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_AUTHOR("David Mosberger <davidm@egauge.net>"); +MODULE_LICENSE("GPL"); |