// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2023, Intel Corporation.
* Intel Visual Sensing Controller Transport Layer Linux driver
*/
#include <linux/acpi.h>
#include <linux/cleanup.h>
#include <linux/crc32.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/iopoll.h>
#include <linux/irq.h>
#include <linux/irqreturn.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <linux/types.h>
#include "vsc-tp.h"
#define VSC_TP_RESET_PIN_TOGGLE_INTERVAL_MS 20
#define VSC_TP_ROM_BOOTUP_DELAY_MS 10
#define VSC_TP_ROM_XFER_POLL_TIMEOUT_US (500 * USEC_PER_MSEC)
#define VSC_TP_ROM_XFER_POLL_DELAY_US (20 * USEC_PER_MSEC)
#define VSC_TP_WAIT_FW_POLL_TIMEOUT (2 * HZ)
#define VSC_TP_WAIT_FW_POLL_DELAY_US (20 * USEC_PER_MSEC)
#define VSC_TP_MAX_XFER_COUNT 5
#define VSC_TP_PACKET_SYNC 0x31
#define VSC_TP_CRC_SIZE sizeof(u32)
#define VSC_TP_MAX_MSG_SIZE 2048
/* SPI xfer timeout size */
#define VSC_TP_XFER_TIMEOUT_BYTES 700
#define VSC_TP_PACKET_PADDING_SIZE 1
#define VSC_TP_PACKET_SIZE(pkt) \
(sizeof(struct vsc_tp_packet) + le16_to_cpu((pkt)->len) + VSC_TP_CRC_SIZE)
#define VSC_TP_MAX_PACKET_SIZE \
(sizeof(struct vsc_tp_packet) + VSC_TP_MAX_MSG_SIZE + VSC_TP_CRC_SIZE)
#define VSC_TP_MAX_XFER_SIZE \
(VSC_TP_MAX_PACKET_SIZE + VSC_TP_XFER_TIMEOUT_BYTES)
#define VSC_TP_NEXT_XFER_LEN(len, offset) \
(len + sizeof(struct vsc_tp_packet) + VSC_TP_CRC_SIZE - offset + VSC_TP_PACKET_PADDING_SIZE)
struct vsc_tp_packet {
__u8 sync;
__u8 cmd;
__le16 len;
__le32 seq;
__u8 buf[] __counted_by(len);
};
struct vsc_tp {
/* do the actual data transfer */
struct spi_device *spi;
/* bind with mei framework */
struct platform_device *pdev;
struct gpio_desc *wakeuphost;
struct gpio_desc *resetfw;
struct gpio_desc *wakeupfw;
/* command sequence number */
u32 seq;
/* command buffer */
void *tx_buf;
void *rx_buf;
atomic_t assert_cnt;
wait_queue_head_t xfer_wait;
vsc_tp_event_cb_t event_notify;
void *event_notify_context;
/* used to protect command download */
struct mutex mutex;
};
/* GPIO resources */
static const struct acpi_gpio_params wakeuphost_gpio = { 0, 0, false };
static const struct acpi_gpio_params wakeuphostint_gpio = { 1, 0, false };
static const struct acpi_gpio_params resetfw_gpio = { 2, 0, false };
static const struct acpi_gpio_params wakeupfw = { 3, 0, false };
static const struct acpi_gpio_mapping vsc_tp_acpi_gpios[] = {
{ "wakeuphost-gpios", &wakeuphost_gpio, 1 },
{ "wakeuphostint-gpios", &wakeuphostint_gpio, 1 },
{ "resetfw-gpios", &resetfw_gpio, 1 },
{ "wakeupfw-gpios", &wakeupfw, 1 },
{}
};
static irqreturn_t vsc_tp_isr(int irq, void *data)
{
struct vsc_tp *tp = data;
atomic_inc(&tp->assert_cnt);
wake_up(&tp->xfer_wait);
return IRQ_WAKE_THREAD;
}
static irqreturn_t vsc_tp_thread_isr(int irq, void *data)
{
struct vsc_tp *tp = data;
if (tp->event_notify)
tp->event_notify(tp->event_notify_context);
return IRQ_HANDLED;
}
/* wakeup firmware and wait for response */
static int vsc_tp_wakeup_request(struct vsc_tp *tp)
{
int ret;
gpiod_set_value_cansleep(tp->wakeupfw, 0);
ret = wait_event_timeout(tp->xfer_wait,
atomic_read(&tp->assert_cnt),
VSC_TP_WAIT_FW_POLL_TIMEOUT);
if (!ret)
return -ETIMEDOUT;
return read_poll_timeout(gpiod_get_value_cansleep, ret, ret,
VSC_TP_WAIT_FW_POLL_DELAY_US,
VSC_TP_WAIT_FW_POLL_TIMEOUT, false,
tp->wakeuphost);
}
static void vsc_tp_wakeup_release(struct vsc_tp *tp)
{
atomic_dec_if_positive(&tp->assert_cnt);
gpiod_set_value_cansleep(tp->wakeupfw, 1);
}
static int vsc_tp_dev_xfer(struct vsc_tp *tp, void *obuf, void *ibuf, size_t len)
{
struct spi_message msg = { 0 };
struct spi_transfer xfer = {
.tx_buf = obuf,
.rx_buf = ibuf,
.len = len,
};
spi_message_init_with_transfers(&msg, &xfer, 1);
return spi_sync_locked(tp->spi, &msg);
}
static int vsc_tp_xfer_helper(struct vsc_tp *tp, struct vsc_tp_packet *pkt,
void *ibuf, u16 ilen)
{
int ret, offset = 0, cpy_len, src_len, dst_len = sizeof(struct vsc_tp_packet);
int next_xfer_len = VSC_TP_PACKET_SIZE(pkt) + VSC_TP_XFER_TIMEOUT_BYTES;
u8 *src, *crc_src, *rx_buf = tp->rx_buf;
int count_down = VSC_TP_MAX_XFER_COUNT;
u32 recv_crc = 0, crc = ~0;
struct vsc_tp_packet ack;
u8 *dst = (u8 *)&ack;
bool synced = false;
do {
ret = vsc_tp_dev_xfer(tp, pkt, rx_buf, next_xfer_len);
if (ret)
return ret;
memset(pkt, 0, VSC_TP_MAX_XFER_SIZE);
if (synced) {
src = rx_buf;
src_len = next_xfer_len;
} else {
src = memchr(rx_buf, VSC_TP_PACKET_SYNC, next_xfer_len);
if (!src)
continue;
synced = true;
src_len = next_xfer_len - (src - rx_buf);
}
/* traverse received data */
while (src_len > 0) {
cpy_len = min(src_len, dst_len);
memcpy(dst, src, cpy_len);
crc_src = src;
src += cpy_len;
src_len -= cpy_len;
dst += cpy_len;
dst_len -= cpy_len;
if (offset < sizeof(ack)) {
offset += cpy_len;
crc = crc32(crc, crc_src, cpy_len);
if (!src_len)
continue;
if (le16_to_cpu(ack.len)) {
dst = ibuf;
dst_len = min(ilen, le16_to_cpu(ack.len));
} else {
dst = (u8 *)&recv_crc;
dst_len = sizeof(recv_crc);
}
} else if (offset < sizeof(ack) + le16_to_cpu(ack.len)) {
offset += cpy_len;
crc = crc32(crc, crc_src, cpy_len);
if (src_len) {
int remain = sizeof(ack) + le16_to_cpu(ack.len) - offset;
cpy_len = min(src_len, remain);
offset += cpy_len;
crc = crc32(crc, src, cpy_len);
src += cpy_len;
src_len -= cpy_len;
if (src_len) {
dst = (u8 *)&recv_crc;
dst_len = sizeof(recv_crc);
continue;
}
}
next_xfer_len = VSC_TP_NEXT_XFER_LEN(le16_to_cpu(ack.len), offset);
} else if (offset < sizeof(ack) + le16_to_cpu(ack.len) + VSC_TP_CRC_SIZE) {
offset += cpy_len;
if (src_len) {
/* terminate the traverse */
next_xfer_len = 0;
break;
}
next_xfer_len = VSC_TP_NEXT_XFER_LEN(le16_to_cpu(ack.len), offset);
}
}
} while (next_xfer_len > 0 && --count_down);
if (next_xfer_len > 0)
return -EAGAIN;
if (~recv_crc != crc || le32_to_cpu(ack.seq) != tp->seq) {
dev_err(&tp->spi->dev, "recv crc or seq error\n");
return -EINVAL;
}
if (ack.cmd == VSC_TP_CMD_ACK || ack.cmd == VSC_TP_CMD_NACK ||
ack.cmd == VSC_TP_CMD_BUSY) {
dev_err(&tp->spi->dev, "recv cmd ack error\n");
return -EAGAIN;
}
return min(le16_to_cpu(ack.len), ilen);
}
/**
* vsc_tp_xfer - transfer data to firmware
* @tp: vsc_tp device handle
* @cmd: the command to be sent to the device
* @obuf: the tx buffer to be sent to the device
* @olen: the length of tx buffer
* @ibuf: the rx buffer to receive from the device
* @ilen: the length of rx buffer
* Return: the length of received data in case of success,
* otherwise negative value
*/
int vsc_tp_xfer(struct vsc_tp *tp, u8 cmd, const void *obuf, size_t olen,
void *ibuf, size_t ilen)
{
struct vsc_tp_packet *pkt = tp->tx_buf;
u32 crc;
int ret;
if (!obuf || !ibuf || olen > VSC_TP_MAX_MSG_SIZE)
return -EINVAL;
guard(mutex)(&tp->mutex);
pkt->sync = VSC_TP_PACKET_SYNC;
pkt->cmd = cmd;
pkt->len = cpu_to_le16(olen);
pkt->seq = cpu_to_le32(++tp->seq);
memcpy(pkt->buf, obuf, olen);
crc = ~crc32(~0, (u8 *)pkt, sizeof(pkt) + olen);
memcpy(pkt->buf + olen, &crc, sizeof(crc));
ret = vsc_tp_wakeup_request(tp);
if (unlikely(ret))
dev_err(&tp->spi->dev, "wakeup firmware failed ret: %d\n", ret);
else
ret = vsc_tp_xfer_helper(tp, pkt, ibuf, ilen);
vsc_tp_wakeup_release(tp);
return ret;
}
EXPORT_SYMBOL_NS_GPL(vsc_tp_xfer, VSC_TP);
/**
* vsc_tp_rom_xfer - transfer data to rom code
* @tp: vsc_tp device handle
* @obuf: the data buffer to be sent to the device
* @ibuf: the buffer to receive data from the device
* @len: the length of tx buffer and rx buffer
* Return: 0 in case of success, negative value in case of error
*/
int vsc_tp_rom_xfer(struct vsc_tp *tp, const void *obuf, void *ibuf, size_t len)
{
size_t words = len / sizeof(__be32);
int ret;
if (len % sizeof(__be32) || len > VSC_TP_MAX_MSG_SIZE)
return -EINVAL;
guard(mutex)(&tp->mutex);
/* rom xfer is big endian */
cpu_to_be32_array(tp->tx_buf, obuf, words);
ret = read_poll_timeout(gpiod_get_value_cansleep, ret,
!ret, VSC_TP_ROM_XFER_POLL_DELAY_US,
VSC_TP_ROM_XFER_POLL_TIMEOUT_US, false,
tp->wakeuphost);
if (ret) {
dev_err(&tp->spi->dev, "wait rom failed ret: %d\n", ret);
return ret;
}
ret = vsc_tp_dev_xfer(tp, tp->tx_buf, ibuf ? tp->rx_buf : NULL, len);
if (ret)
return ret;
if (ibuf)
be32_to_cpu_array(ibuf, tp->rx_buf, words);
return ret;
}
/**
* vsc_tp_reset - reset vsc transport layer
* @tp: vsc_tp device handle
*/
void vsc_tp_reset(struct vsc_tp *tp)
{
disable_irq(tp->spi->irq);
/* toggle reset pin */
gpiod_set_value_cansleep(tp->resetfw, 0);
msleep(VSC_TP_RESET_PIN_TOGGLE_INTERVAL_MS);
gpiod_set_value_cansleep(tp->resetfw, 1);
/* wait for ROM */
msleep(VSC_TP_ROM_BOOTUP_DELAY_MS);
/*
* Set default host wakeup pin to non-active
* to avoid unexpected host irq interrupt.
*/
gpiod_set_value_cansleep(tp->wakeupfw, 1);
atomic_set(&tp->assert_cnt, 0);
enable_irq(tp->spi->irq);
}
EXPORT_SYMBOL_NS_GPL(vsc_tp_reset, VSC_TP);
/**
* vsc_tp_need_read - check if device has data to sent
* @tp: vsc_tp device handle
* Return: true if device has data to sent, otherwise false
*/
bool vsc_tp_need_read(struct vsc_tp *tp)
{
if (!atomic_read(&tp->assert_cnt))
return false;
if (!gpiod_get_value_cansleep(tp->wakeuphost))
return false;
if (!gpiod_get_value_cansleep(tp->wakeupfw))
return false;
return true;
}
EXPORT_SYMBOL_NS_GPL(vsc_tp_need_read, VSC_TP);
/**
* vsc_tp_register_event_cb - register a callback function to receive event
* @tp: vsc_tp device handle
* @event_cb: callback function
* @context: execution context of event callback
* Return: 0 in case of success, negative value in case of error
*/
int vsc_tp_register_event_cb(struct vsc_tp *tp, vsc_tp_event_cb_t event_cb,
void *context)
{
tp->event_notify = event_cb;
tp->event_notify_context = context;
return 0;
}
EXPORT_SYMBOL_NS_GPL(vsc_tp_register_event_cb, VSC_TP);
/**
* vsc_tp_request_irq - request irq for vsc_tp device
* @tp: vsc_tp device handle
*/
int vsc_tp_request_irq(struct vsc_tp *tp)
{
struct spi_device *spi = tp->spi;
struct device *dev = &spi->dev;
int ret;
irq_set_status_flags(spi->irq, IRQ_DISABLE_UNLAZY);
ret = request_threaded_irq(spi->irq, vsc_tp_isr, vsc_tp_thread_isr,
IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
dev_name(dev), tp);
if (ret)
return ret;
return 0;
}
EXPORT_SYMBOL_NS_GPL(vsc_tp_request_irq, VSC_TP);
/**
* vsc_tp_free_irq - free irq for vsc_tp device
* @tp: vsc_tp device handle
*/
void vsc_tp_free_irq(struct vsc_tp *tp)
{
free_irq(tp->spi->irq, tp);
}
EXPORT_SYMBOL_NS_GPL(vsc_tp_free_irq, VSC_TP);
/**
* vsc_tp_intr_synchronize - synchronize vsc_tp interrupt
* @tp: vsc_tp device handle
*/
void vsc_tp_intr_synchronize(struct vsc_tp *tp)
{
synchronize_irq(tp->spi->irq);
}
EXPORT_SYMBOL_NS_GPL(vsc_tp_intr_synchronize, VSC_TP);
/**
* vsc_tp_intr_enable - enable vsc_tp interrupt
* @tp: vsc_tp device handle
*/
void vsc_tp_intr_enable(struct vsc_tp *tp)
{
enable_irq(tp->spi->irq);
}
EXPORT_SYMBOL_NS_GPL(vsc_tp_intr_enable, VSC_TP);
/**
* vsc_tp_intr_disable - disable vsc_tp interrupt
* @tp: vsc_tp device handle
*/
void vsc_tp_intr_disable(struct vsc_tp *tp)
{
disable_irq(tp->spi->irq);
}
EXPORT_SYMBOL_NS_GPL(vsc_tp_intr_disable, VSC_TP);
static int vsc_tp_match_any(struct acpi_device *adev, void *data)
{
struct acpi_device **__adev = data;
*__adev = adev;
return 1;
}
static int vsc_tp_probe(struct spi_device *spi)
{
struct vsc_tp *tp;
struct platform_device_info pinfo = {
.name = "intel_vsc",
.data = &tp,
.size_data = sizeof(tp),
.id = PLATFORM_DEVID_NONE,
};
struct device *dev = &spi->dev;
struct platform_device *pdev;
struct acpi_device *adev;
int ret;
tp = devm_kzalloc(dev, sizeof(*tp), GFP_KERNEL);
if (!tp)
return -ENOMEM;
tp->tx_buf = devm_kzalloc(dev, VSC_TP_MAX_XFER_SIZE, GFP_KERNEL);
if (!tp->tx_buf)
return -ENOMEM;
tp->rx_buf = devm_kzalloc(dev, VSC_TP_MAX_XFER_SIZE, GFP_KERNEL);
if (!tp->rx_buf)
return -ENOMEM;
ret = devm_acpi_dev_add_driver_gpios(dev, vsc_tp_acpi_gpios);
if (ret)
return ret;
tp->wakeuphost = devm_gpiod_get(dev, "wakeuphost", GPIOD_IN);
if (IS_ERR(tp->wakeuphost))
return PTR_ERR(tp->wakeuphost);
tp->resetfw = devm_gpiod_get(dev, "resetfw", GPIOD_OUT_HIGH);
if (IS_ERR(tp->resetfw))
return PTR_ERR(tp->resetfw);
tp->wakeupfw = devm_gpiod_get(dev, "wakeupfw", GPIOD_OUT_HIGH);
if (IS_ERR(tp->wakeupfw))
return PTR_ERR(tp->wakeupfw);
atomic_set(&tp->assert_cnt, 0);
init_waitqueue_head(&tp->xfer_wait);
tp->spi = spi;
irq_set_status_flags(spi->irq, IRQ_DISABLE_UNLAZY);
ret = request_threaded_irq(spi->irq, vsc_tp_isr, vsc_tp_thread_isr,
IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
dev_name(dev), tp);
if (ret)
return ret;
mutex_init(&tp->mutex);
/* only one child acpi device */
ret = acpi_dev_for_each_child(ACPI_COMPANION(dev),
vsc_tp_match_any, &adev);
if (!ret) {
ret = -ENODEV;
goto err_destroy_lock;
}
pinfo.fwnode = acpi_fwnode_handle(adev);
pdev = platform_device_register_full(&pinfo);
if (IS_ERR(pdev)) {
ret = PTR_ERR(pdev);
goto err_destroy_lock;
}
tp->pdev = pdev;
spi_set_drvdata(spi, tp);
return 0;
err_destroy_lock:
mutex_destroy(&tp->mutex);
free_irq(spi->irq, tp);
return ret;
}
static void vsc_tp_remove(struct spi_device *spi)
{
struct vsc_tp *tp = spi_get_drvdata(spi);
platform_device_unregister(tp->pdev);
mutex_destroy(&tp->mutex);
free_irq(spi->irq, tp);
}
static void vsc_tp_shutdown(struct spi_device *spi)
{
struct vsc_tp *tp = spi_get_drvdata(spi);
platform_device_unregister(tp->pdev);
mutex_destroy(&tp->mutex);
vsc_tp_reset(tp);
free_irq(spi->irq, tp);
}
static const struct acpi_device_id vsc_tp_acpi_ids[] = {
{ "INTC1009" }, /* Raptor Lake */
{ "INTC1058" }, /* Tiger Lake */
{ "INTC1094" }, /* Alder Lake */
{ "INTC10D0" }, /* Meteor Lake */
{}
};
MODULE_DEVICE_TABLE(acpi, vsc_tp_acpi_ids);
static struct spi_driver vsc_tp_driver = {
.probe = vsc_tp_probe,
.remove = vsc_tp_remove,
.shutdown = vsc_tp_shutdown,
.driver = {
.name = "vsc-tp",
.acpi_match_table = vsc_tp_acpi_ids,
},
};
module_spi_driver(vsc_tp_driver);
MODULE_AUTHOR("Wentong Wu <[email protected]>");
MODULE_AUTHOR("Zhifeng Wang <[email protected]>");
MODULE_DESCRIPTION("Intel Visual Sensing Controller Transport Layer");
MODULE_LICENSE("GPL");
Codebase Browser
linux