On 26-02-09, Sascha Hauer wrote: > On Thu, Feb 05, 2026 at 04:45:05PM +0100, Marco Felsch wrote: > > This adds the EFI core driver to communicate with the system > > co-processor. > > This EFI doesn't have anything to do with the Extensible Firmware > Interface, right? Could you add some note what it means to commit > message, Kconfig and to the description in hgs-efi.c to avoid confusion?
Sure! > > Signed-off-by: Marco Felsch <[email protected]> > > --- > > drivers/mfd/Kconfig | 8 + > > drivers/mfd/Makefile | 1 + > > drivers/mfd/hgs-efi.c | 473 > > ++++++++++++++++++++++++++++++++++++++++++++++++++ > > include/mfd/hgs-efi.h | 46 +++++ > > 4 files changed, 528 insertions(+) > > > > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig > > index > > 471f85cd63dad30b39017f694b594b768e463a15..f09e3903bcb50556b1556a84500ae73d91a5a63d > > 100644 > > --- a/drivers/mfd/Kconfig > > +++ b/drivers/mfd/Kconfig > > @@ -158,4 +158,12 @@ config MFD_ATMEL_SMC > > bool > > select MFD_SYSCON > > > > +config MFD_HGS_EFI > > + tristate "Hexagon Geosystems EFI core driver" > > + depends on SERIAL_DEV_BUS > > + select CRC16 > > + help > > + Select this to get support for the EFI Co-Processor > > + device found on several devices in the System1600 platform. > > + > > endmenu > > diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile > > index > > 88480f70640d464e0e12241ec422a63ca860330d..9d27b0bc336a908f1245eb7f1d257a23e271ebd7 > > 100644 > > --- a/drivers/mfd/Makefile > > +++ b/drivers/mfd/Makefile > > @@ -27,3 +27,4 @@ obj-$(CONFIG_MFD_ATMEL_SMC) += atmel-smc.o > > obj-$(CONFIG_MFD_ROHM_BD718XX) += rohm-bd718x7.o > > obj-$(CONFIG_MFD_PCA9450) += pca9450.o > > obj-$(CONFIG_MFD_TPS65219) += tps65219.o > > +obj-$(CONFIG_MFD_HGS_EFI) += hgs-efi.o > > diff --git a/drivers/mfd/hgs-efi.c b/drivers/mfd/hgs-efi.c > > new file mode 100644 > > index > > 0000000000000000000000000000000000000000..e548a6b209a6f64cecd8d56edcaa565b0b6d2657 > > --- /dev/null > > +++ b/drivers/mfd/hgs-efi.c > > @@ -0,0 +1,473 @@ > > +// SPDX-License-Identifier: GPL-2.0-only > > +// SPDX-FileCopyrightText: 2025 Pengutronix > > + > > +/* > > + * Multifunction core driver for Hexagon Geosystems EFI MCU that is > > connected > > + * via dedicated UART port. The communication protocol between both > > parties is > > + * called Sensor Protocol (SEP). > > + * > > + * Based on drivers/mfd/rave-sp.c > > + */ > > + > > +#include <asm/unaligned.h> > > +#include <common.h> > > +#include <init.h> > > +#include <of_device.h> > > +#include <mfd/hgs-efi.h> > > +#include <linux/crc16.h> > > +#include <linux/ctype.h> > > +#include <linux/string.h> > > +#include <mfd/hgs-efi.h> > > + > > +#define HGS_EFI_SEP_ASCII_SYNCBYTE 'S' > > +#define HGS_EFI_SEP_ASCII_MSG_TYPE_CMD 'C' > > +#define HGS_EFI_SEP_ASCII_MSG_TYPE_EVENT 'E' > > +#define HGS_EFI_SEP_ASCII_MSG_TYPE_REPLY 'R' > > +#define HGS_EFI_SEP_ASCII_DELIM ',' > > +#define HGS_EFI_SEP_ASCII_HDR_END ':' > > + > > +/* Non addressed ascii header format */ > > +struct hgs_efi_sep_ascii_hdr { > > + u8 syncbyte; > > + u8 msg_type; > > + u8 msg_id[5]; /* u16 dec number */ > > + u8 delim; > > + u8 crc16[4]; /* u16 hex number */ > > + u8 hdr_end; > > +} __packed; > > + > > +#define HGS_EFI_SEP_RX_BUFFER_SIZE 64 > > +#define HGS_EFI_SEP_FRAME_PREAMBLE_SZ 2 > > +#define HGS_EFI_SEP_FRAME_POSTAMBLE_SZ 2 > > + > > +enum hgs_efi_sep_deframer_state { > > + HGS_EFI_SEP_EXPECT_SOF, > > + HGS_EFI_SEP_EXPECT_DATA, > > +}; > > + > > +/** > > + * struct hgs_efi_deframer - Device protocol deframer > > + * > > + * @state: Current state of the deframer > > + * @data: Buffer used to collect deframed data > > + * @length: Number of bytes de-framed so far > > + */ > > +struct hgs_efi_deframer { > > + enum hgs_efi_sep_deframer_state state; > > + unsigned char data[HGS_EFI_SEP_RX_BUFFER_SIZE]; > > + size_t length; > > +}; > > + > > +/** > > + * struct hgs_efi_reply - Reply as per SEP > > + * > > + * @length: Expected reply length > > + * @data: Buffer to store reply payload in > > + * @msg_id: Expected SEP msg-id > > + * @received: Successful reply reception > > + */ > > +struct hgs_efi_reply { > > + size_t length; > > + void *data; > > + u16 msg_id; > > + bool received; > > +}; > > + > > +struct hgs_efi_sep_coder { > > + int (*encode)(struct hgs_efi *efi, struct hgs_sep_cmd *cmd, u8 *buf); > > + int (*process_frame)(struct hgs_efi *efi, void *buf, size_t size); > > + unsigned int sep_header_hdrsize; > > + char sep_sof_char; > > +}; > > + > > +struct hgs_efi { > > + struct device dev; > > + struct serdev_device *serdev; > > + const struct hgs_efi_sep_coder *coder; > > + struct hgs_efi_deframer deframer; > > + struct hgs_efi_reply *reply; > > +}; > > + > > +static void hgs_efi_write(struct hgs_efi *efi, const u8 *data, size_t > > data_size) > > +{ > > + print_hex_dump_bytes("hgs-efi tx: ", DUMP_PREFIX_NONE, data, data_size); > > + > > + /* timeout is ignored, instead polling_window is used */ > > + serdev_device_write(efi->serdev, data, data_size, SECOND); > > +} > > + > > +int hgs_efi_exec(struct hgs_efi *efi, struct hgs_sep_cmd *cmd) > > +{ > > + struct device *dev = efi->serdev->dev; > > + struct hgs_efi_reply reply = { > > + .msg_id = cmd->msg_id, > > + .data = cmd->reply_data, > > + .length = cmd->reply_data_size, > > + .received = false, > > + }; > > + unsigned int max_msg_len; > > + u8 *msg, *p; > > + int ret; > > + > > + switch (cmd->type) { > > + case HGS_SEP_MSG_TYPE_COMMAND: > > + case HGS_SEP_MSG_TYPE_EVENT: > > + break; > > + case HGS_SEP_MSG_TYPE_REPLY: > > + dev_warn(dev, "MCU initiated communication is not supported > > yet!\n"); > > + return -EINVAL; > > + default: > > + dev_warn(dev, "Unknown EFI msg-type %#x\n", cmd->type); > > + return -EINVAL; > > + } > > + > > + max_msg_len = HGS_EFI_SEP_FRAME_PREAMBLE_SZ + > > + HGS_EFI_SEP_FRAME_POSTAMBLE_SZ + > > + efi->coder->sep_header_hdrsize + cmd->payload_size; > > + msg = p = xzalloc(max_msg_len); > > + if (!msg) { > > + dev_err(dev, "No memory\n"); > > + return -ENOMEM; > > + } > > + > > + /* MCU serial flush preamble */ > > + *p++ = '\r'; > > + *p++ = '\n'; > > + > > + ret = efi->coder->encode(efi, cmd, p); > > + if (ret < 0) { > > + free(msg); > > + return ret; > > + } > > + > > + p += ret; > > + > > + /* SEP postamble */ > > + *p++ = '\r'; > > + *p++ = '\n'; > > + > > + efi->reply = &reply; > > + hgs_efi_write(efi, msg, p - msg); > > + > > + free(msg); > > + > > + if (cmd->type == HGS_SEP_MSG_TYPE_EVENT) { > > + efi->reply = NULL; > > + return 0; > > + } > > + > > + /* > > + * is_timeout will implicitly poll serdev via poller > > + * infrastructure > > + */ > > + ret = wait_on_timeout(SECOND, reply.received); > > + if (ret) > > + dev_err(dev, "Command timeout\n"); > > + > > + efi->reply = NULL; > > + > > + return ret; > > +} > > + > > +#define HGS_SEP_DOUBLE_QUOTE_SUB_VAL 0x1a > > + > > +char *hgs_efi_extract_str_response(u8 *buf) > > +{ > > + unsigned char *start; > > + unsigned char *end; > > + unsigned char *p; > > + size_t i; > > + > > + if (!buf || buf[0] != '"') { > > + pr_warn("hgs-efi: No start \" char found in string response\n"); > > Add above the includes: > > #define pr_fmt(fmt) "hgs-efi: " fmt > > And drp the prefix here. Will do. > > + return ERR_PTR(-EINVAL); > > + } > > + > > + start = &buf[1]; > > + end = strrchr(start, '"'); > > + if (!end) { > > + pr_warn("hgs-efi: No end \" char found in string response\n"); > > + return ERR_PTR(-EINVAL); > > + } > > + *end = '\0'; > > + > > + /* > > + * Last step, check for substition val in string reply > > + * and re-substitute it. > > + */ > > + p = start; > > + for (i = 0; i < strlen(start); i++) > > + if (*p == HGS_SEP_DOUBLE_QUOTE_SUB_VAL) > > + *p = '"'; > > + > > + return start; > > +} > > + > > +static int hgs_sep_ascii_encode(struct hgs_efi *efi, struct hgs_sep_cmd > > *cmd, > > + u8 *buf) > > +{ > > + struct device *dev = efi->serdev->dev; > > + size_t hdr_len; > > + char msg_type; > > + char *hdr; > > + > > + switch (cmd->type) { > > + case HGS_SEP_MSG_TYPE_COMMAND: > > + msg_type = 'C'; > > + break; > > + case HGS_SEP_MSG_TYPE_EVENT: > > + msg_type = 'E'; > > + break; > > + default: > > + /* Should never happen */ > > + return -EINVAL; > > + } > > + > > + /* > > + * The ASCII coder doesn't care about the CRC, also the CRC handling > > + * has a few flaws. Therefore skip it for now. > > + */ > > + hdr = xasprintf("S%c%u:", msg_type, cmd->msg_id); > > xasprintf also doesn't fail. Thanks > > + if (!hdr) { > > + dev_err(dev, "No memory\n"); > > + return -ENOMEM; > > + } > > + > > + /* Now copy the header and the payload to the buffer */ > > + hdr_len = strlen(hdr); > > + memcpy(buf, hdr, hdr_len); > > You could simplify the above by doing: > > hdr_len = sprintf(buf, "S%c%u:", msg_type, cmd->msg_id); Thats a good point, thanks! > > > + memcpy(buf + hdr_len, cmd->payload, cmd->payload_size); > > + > > + free(hdr); > > + > > + return hdr_len + cmd->payload_size; > > +} > > + > > +static int > > +hgs_sep_process_ascii_frame(struct hgs_efi *efi, void *_buf, size_t size) > > +{ > > + struct device *dev = efi->serdev->dev; > > + unsigned char *payload; > > + unsigned int copy_bytes; > > + unsigned int msgid; > > + size_t payload_len; > > + u8 *buf = _buf; > > + size_t hdrlen; > > + char *p; > > + int ret; > > + > > + /* > > + * Non addressing ASCII format: > > + * S[MsgType][MsgID](,[CRC]):[Payload] > > + */ > > + if (buf[1] != HGS_EFI_SEP_ASCII_MSG_TYPE_REPLY) { > > check buf[0] != 0 before looking at buf[1]? I could do this, but this function is only called if buf[0] has the correct value (see: HGS_EFI_SEP_EXPECT_SOF). > > + dev_warn(dev, "Invalid msg-type %c(%#x)\n", *buf, *buf); > > + return -EINVAL; > > + } > > + > > + /* Split header from payload first for the following str-ops on buf */ > > + payload = strstr(buf, ":"); > > + if (!payload) { > > + dev_warn(dev, "Failed to find header delim\n"); > > + return -EINVAL; > > + } > > + > > + hdrlen = payload - buf; > > + if (hdrlen > sizeof(struct hgs_efi_sep_ascii_hdr)) { > > + dev_warn(dev, "Invalid header len detected\n"); > > + return -EINVAL; > > + } > > + > > + *payload = 0; > > + payload++; > > + > > + /* > > + * Albeit the CRC is optional and the calc as a few flaws the coder may > > s/as/has/ thanks. > > > + * has added it. Skip the CRC check but do the msg-id check. > > + */ > > + p = strstr(buf, ","); > > + if (p) > > + *p = 0; > > + > > + ret = kstrtouint(&buf[2], 10, &msgid); > > + if (ret) { > > + dev_warn(dev, "Failed to parse msgid, ret:%d\n", ret); > > + return -EINVAL; > > + } > > + > > + if (msgid != efi->reply->msg_id) { > > + dev_warn(dev, "Wrong msg-id received, ignore frame (%u != > > %u)\n", > > + msgid, efi->reply->msg_id); > > + return -EINVAL; > > + } > > + > > + payload_len = size - hdrlen; > > + copy_bytes = payload_len; > > + if (payload_len > efi->reply->length) { > > + dev_warn(dev, "Reply buffer to small, dropping remaining %zu > > bytes\n", > > + payload_len - efi->reply->length); > > + copy_bytes = efi->reply->length; > > + } > > + > > + memcpy(efi->reply->data, payload, copy_bytes); > > + > > + return 0; > > +} > > + > > +static const struct hgs_efi_sep_coder hgs_efi_ascii_coder = { > > + .encode = hgs_sep_ascii_encode, > > + .process_frame = hgs_sep_process_ascii_frame, > > + .sep_header_hdrsize = sizeof(struct hgs_efi_sep_ascii_hdr), > > + .sep_sof_char = HGS_EFI_SEP_ASCII_SYNCBYTE, > > +}; > > + > > +static bool hgs_efi_eof_received(struct hgs_efi_deframer *deframer) > > +{ > > + const char eof_seq[] = { '\r', '\n' }; > > + > > + if (deframer->length <= 2) > > + return false; > > + > > + if (memcmp(&deframer->data[deframer->length - 2], eof_seq, 2)) > > + return false; > > + > > + return true; > > +} > > + > > +static void hgs_efi_receive_frame(struct hgs_efi *efi, > > + struct hgs_efi_deframer *deframer) > > +{ > > + int ret; > > + > > + if (deframer->length < efi->coder->sep_header_hdrsize) { > > + dev_warn(efi->serdev->dev, "Bad frame: Too short\n"); > > + return; > > + } > > + > > + print_hex_dump_bytes("hgs-efi rx-frame: ", DUMP_PREFIX_NONE, > > + deframer->data, deframer->length); > > + > > + ret = efi->coder->process_frame(efi, deframer->data, > > + deframer->length - HGS_EFI_SEP_FRAME_PREAMBLE_SZ); > > + if (!ret) > > + efi->reply->received = true; > > +} > > + > > +static int hgs_efi_receive_buf(struct serdev_device *serdev, > > + const unsigned char *buf, size_t size) > > +{ > > + struct device *dev = serdev->dev; > > + struct hgs_efi *efi = dev->priv; > > + struct hgs_efi_deframer *deframer = &efi->deframer; > > + const unsigned char *src = buf; > > + const unsigned char *end = buf + size; > > + > > + print_hex_dump_bytes("hgs-efi rx-bytes: ", DUMP_PREFIX_NONE, buf, size); > > + > > + while (src < end) { > > + const unsigned char byte = *src++; > > + > > + switch (deframer->state) { > > + case HGS_EFI_SEP_EXPECT_SOF: > > + if (byte == efi->coder->sep_sof_char) > > + deframer->state = HGS_EFI_SEP_EXPECT_DATA; > > + deframer->data[deframer->length++] = byte; > > + break; > > + case HGS_EFI_SEP_EXPECT_DATA: > > + if (deframer->length >= sizeof(deframer->data)) { > > + dev_warn(dev, "Bad frame: Too long\n"); > > + goto frame_reset; > > + } > > + > > + deframer->data[deframer->length++] = byte; > > + if (hgs_efi_eof_received(deframer)) { > > + hgs_efi_receive_frame(efi, deframer); > > + goto frame_reset; > > + } > > + } > > + } > > + > > + /* > > + * All bytes processed but no EOF detected yet which because the serdev > > s/which// > > > + * poller may called us to early. Keep the deframer state to continue > > + * the work where we finished. > > + */ > > + return size; > > + > > +frame_reset: > > + memset(deframer->data, 0, deframer->length); > > + deframer->length = 0; > > + deframer->state = HGS_EFI_SEP_EXPECT_SOF; > > + > > + return src - buf; > > +} > > + > > +static int hgs_efi_register_dev(struct hgs_efi *efi) > > +{ > > + struct device *dev = &efi->dev; > > + > > + dev->parent = efi->serdev->dev; > > + dev_set_name(dev, "%s", "efi"); > > dev_set_name(dev, "efi"); Sure. > > + dev->id = DEVICE_ID_SINGLE; > > + > > + return register_device(dev); > > +} > > + > > +static int hgs_efi_probe(struct device *dev) > > +{ > > + struct serdev_device *serdev = to_serdev_device(dev->parent); > > + struct hgs_efi *efi; > > + u32 baud; > > + int ret; > > + > > + if (of_property_read_u32(dev->of_node, "current-speed", &baud)) { > > + dev_err(dev, > > + "'current-speed' is not specified in device node\n"); > > + return -EINVAL; > > + } > > + > > + efi = xzalloc(sizeof(*efi)); > > + if (!efi) > > + return -ENOMEM; > > + > > + efi->coder = of_device_get_match_data(dev); > > + if (!efi->coder) { > > + free(efi); > > + return -ENODEV; > > + } > > + > > + efi->serdev = serdev; > > + > > + dev->priv = efi; > > + serdev->dev = dev; > > + serdev->receive_buf = hgs_efi_receive_buf; > > + serdev->polling_interval = 200 * MSECOND; > > + serdev->polling_window = 10 * MSECOND; > > + > > + ret = serdev_device_open(serdev); > > This registers a poller, so when one of the calls below fails this might > have some bad consequences. Oh, we do not have a serdev_device_close(), > I won't look further ;) Hm.. something we should fix. Let me check if I can add a serdev_device_close() routine real quick else I would add a comment. Regards, Marco > > Sascha > > > + if (ret) > > + return ret; > > + > > + serdev_device_set_baudrate(serdev, baud); > > + > > + ret = hgs_efi_register_dev(efi); > > + if (ret) { > > + dev_err(dev, "Failed to register EFI device\n"); > > + return ret; > > + }; > > + > > + return of_platform_populate(dev->of_node, NULL, dev); > > +} > > + > > +static const struct of_device_id __maybe_unused hgs_efi_dt_ids[] = { > > + { .compatible = "hgs,efi-gs05", .data = &hgs_efi_ascii_coder }, > > + { /* sentinel */ } > > +}; > > +MODULE_DEVICE_TABLE(of, lgs_efi_dt_ids); > > + > > +static struct driver hgs_efi_drv = { > > + .name = "hgs-efi", > > + .probe = hgs_efi_probe, > > + .of_compatible = DRV_OF_COMPAT(hgs_efi_dt_ids), > > +}; > > +console_platform_driver(hgs_efi_drv); > > -- > Pengutronix e.K. | | > Steuerwalder Str. 21 | http://www.pengutronix.de/ | > 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | > -- #gernperDu #CallMeByMyFirstName Pengutronix e.K. | | Steuerwalder Str. 21 | https://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-9 |
