diff options
Diffstat (limited to 'drivers/misc/mei/vsc-tp.c')
| -rw-r--r-- | drivers/misc/mei/vsc-tp.c | 555 |
1 files changed, 555 insertions, 0 deletions
diff --git a/drivers/misc/mei/vsc-tp.c b/drivers/misc/mei/vsc-tp.c new file mode 100644 index 000000000000..6f4a4be6ccb5 --- /dev/null +++ b/drivers/misc/mei/vsc-tp.c @@ -0,0 +1,555 @@ +// 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_ASSERTED_TIMEOUT (2 * HZ) +#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 }, + {} +}; + +/* 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) && + gpiod_get_value_cansleep(tp->wakeuphost), + VSC_TP_WAIT_FW_ASSERTED_TIMEOUT); + if (!ret) + return -ETIMEDOUT; + + return 0; +} + +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, tp->rx_buf, len); + if (ret) + return ret; + + if (ibuf) + cpu_to_be32_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_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 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; +} + +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 platform_device_info pinfo = { 0 }; + struct device *dev = &spi->dev; + struct platform_device *pdev; + struct acpi_device *adev; + struct vsc_tp *tp; + 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 = devm_request_threaded_irq(dev, 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); + + pinfo.name = "intel_vsc"; + pinfo.data = &tp; + pinfo.size_data = sizeof(tp); + pinfo.id = PLATFORM_DEVID_NONE; + + 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); + + 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); +} + +static const struct acpi_device_id vsc_tp_acpi_ids[] = { + { "INTC1009" }, /* Raptor Lake */ + { "INTC1058" }, /* Tiger Lake */ + { "INTC1094" }, /* Alder Lake */ + {} +}; +MODULE_DEVICE_TABLE(acpi, vsc_tp_acpi_ids); + +static struct spi_driver vsc_tp_driver = { + .probe = vsc_tp_probe, + .remove = vsc_tp_remove, + .driver = { + .name = "vsc-tp", + .acpi_match_table = vsc_tp_acpi_ids, + }, +}; +module_spi_driver(vsc_tp_driver); + +MODULE_AUTHOR("Wentong Wu <wentong.wu@intel.com>"); +MODULE_AUTHOR("Zhifeng Wang <zhifeng.wang@intel.com>"); +MODULE_DESCRIPTION("Intel Visual Sensing Controller Transport Layer"); +MODULE_LICENSE("GPL"); |