diff options
Diffstat (limited to 'drivers/misc/gdsys_ioep.c')
| -rw-r--r-- | drivers/misc/gdsys_ioep.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/drivers/misc/gdsys_ioep.c b/drivers/misc/gdsys_ioep.c new file mode 100644 index 0000000000..7f17095cc5 --- /dev/null +++ b/drivers/misc/gdsys_ioep.c @@ -0,0 +1,209 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * (C) Copyright 2017 + * Mario Six, Guntermann & Drunck GmbH, mario.six@gdsys.cc + * + * based on the cmd_ioloop driver/command, which is + * + * (C) Copyright 2014 + * Dirk Eibach, Guntermann & Drunck GmbH, dirk.eibach@gdsys.cc + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <dm.h> +#include <misc.h> +#include <regmap.h> + +#include "gdsys_ioep.h" + +/** + * struct gdsys_ioep_priv - Private data structure for IOEP devices + * @map: Register map to be used for the device + * @state: Flag to keep the current status of the RX control (enabled/disabled) + */ +struct gdsys_ioep_priv { + struct regmap *map; + bool state; +}; + +/** + * enum last_spec - Convenience enum for read data sanity check + * @READ_DATA_IS_LAST: The data to be read should be the final data of the + * current packet + * @READ_DATA_IS_NOT_LAST: The data to be read should not be the final data of + * the current packet + */ +enum last_spec { + READ_DATA_IS_LAST, + READ_DATA_IS_NOT_LAST, +}; + +static int gdsys_ioep_set_receive(struct udevice *dev, bool val) +{ + struct gdsys_ioep_priv *priv = dev_get_priv(dev); + u16 state; + + priv->state = !priv->state; + + if (val) + state = CTRL_PROC_RECEIVE_ENABLE; + else + state = ~CTRL_PROC_RECEIVE_ENABLE; + + gdsys_ioep_set(priv->map, tx_control, state); + + if (val) { + /* Set device address to dummy 1 */ + gdsys_ioep_set(priv->map, device_address, 1); + } + + return !priv->state; +} + +static int gdsys_ioep_send(struct udevice *dev, int offset, + const void *buf, int size) +{ + struct gdsys_ioep_priv *priv = dev_get_priv(dev); + int k; + u16 *p = (u16 *)buf; + + for (k = 0; k < size; ++k) + gdsys_ioep_set(priv->map, transmit_data, *(p++)); + + gdsys_ioep_set(priv->map, tx_control, CTRL_PROC_RECEIVE_ENABLE | + CTRL_FLUSH_TRANSMIT_BUFFER); + + return 0; +} + +/** + * receive_byte_buffer() - Read data from a IOEP device + * @dev: The IOEP device to read data from + * @len: The length of the data to read + * @buffer: The buffer to read the data into + * @last_spec: Flag to indicate if the data to be read in this call should be + * the final data of the current packet (i.e. it should be empty + * after this read) + * + * Return: 0 if OK, -ve on error + */ +static int receive_byte_buffer(struct udevice *dev, uint len, + u16 *buffer, enum last_spec last_spec) +{ + struct gdsys_ioep_priv *priv = dev_get_priv(dev); + int k; + int ret = -EIO; + + for (k = 0; k < len; ++k) { + u16 rx_tx_status; + + gdsys_ioep_get(priv->map, receive_data, buffer++); + + gdsys_ioep_get(priv->map, rx_tx_status, &rx_tx_status); + /* + * Sanity check: If the data read should have been the last, + * but wasn't, something is wrong + */ + if (k == (len - 1) && (last_spec == READ_DATA_IS_NOT_LAST || + rx_tx_status & STATE_RX_DATA_LAST)) + ret = 0; + } + + if (ret) + debug("%s: Error while receiving bufer (err = %d)\n", + dev->name, ret); + + return ret; +} + +static int gdsys_ioep_receive(struct udevice *dev, int offset, void *buf, + int size) +{ + int ret; + struct io_generic_packet header; + u16 *p = (u16 *)buf; + const int header_words = sizeof(struct io_generic_packet) / sizeof(u16); + uint len; + + /* Read the packet header */ + ret = receive_byte_buffer(dev, header_words, p, READ_DATA_IS_NOT_LAST); + if (ret) { + debug("%s: Failed to read header data (err = %d)\n", + dev->name, ret); + return ret; + } + + memcpy(&header, p, header_words * sizeof(u16)); + p += header_words; + + /* Get payload data length */ + len = (header.packet_length + 1) / sizeof(u16); + + /* Read the packet payload */ + ret = receive_byte_buffer(dev, len, p, READ_DATA_IS_LAST); + if (ret) { + debug("%s: Failed to read payload data (err = %d)\n", + dev->name, ret); + return ret; + } + + return 0; +} + +static int gdsys_ioep_get_and_reset_status(struct udevice *dev, int msgid, + void *tx_msg, int tx_size, + void *rx_msg, int rx_size) +{ + struct gdsys_ioep_priv *priv = dev_get_priv(dev); + const u16 mask = STATE_RX_DIST_ERR | STATE_RX_LENGTH_ERR | + STATE_RX_FRAME_CTR_ERR | STATE_RX_FCS_ERR | + STATE_RX_PACKET_DROPPED | STATE_TX_ERR; + u16 *status = rx_msg; + + gdsys_ioep_get(priv->map, rx_tx_status, status); + + gdsys_ioep_set(priv->map, rx_tx_status, *status); + + return (*status & mask) ? 1 : 0; +} + +static const struct misc_ops gdsys_ioep_ops = { + .set_enabled = gdsys_ioep_set_receive, + .write = gdsys_ioep_send, + .read = gdsys_ioep_receive, + .call = gdsys_ioep_get_and_reset_status, +}; + +static int gdsys_ioep_probe(struct udevice *dev) +{ + struct gdsys_ioep_priv *priv = dev_get_priv(dev); + int ret; + + ret = regmap_init_mem(dev_ofnode(dev), &priv->map); + if (ret) { + debug("%s: Could not initialize regmap (err = %d)", + dev->name, ret); + return ret; + } + + priv->state = false; + + return 0; +} + +static const struct udevice_id gdsys_ioep_ids[] = { + { .compatible = "gdsys,io-endpoint" }, + { } +}; + +U_BOOT_DRIVER(gdsys_ioep) = { + .name = "gdsys_ioep", + .id = UCLASS_MISC, + .ops = &gdsys_ioep_ops, + .flags = DM_UC_FLAG_SEQ_ALIAS, + .of_match = gdsys_ioep_ids, + .probe = gdsys_ioep_probe, + .priv_auto_alloc_size = sizeof(struct gdsys_ioep_priv), +}; |