This driver implements the Greybus bridged phy spi class protocol.
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
drivers/greybus/spi.c | 79 ++++++
drivers/greybus/spilib.c | 565 +++++++++++++++++++++++++++++++++++++++++++++++
drivers/greybus/spilib.h | 24 +
3 files changed, 668 insertions(+)
--- /dev/null
+++ b/drivers/greybus/spi.c
@@ -0,0 +1,79 @@
+/*
+ * SPI bridge PHY driver.
+ *
+ * Copyright 2014-2016 Google Inc.
+ * Copyright 2014-2016 Linaro Ltd.
+ *
+ * Released under the GPLv2 only.
+ */
+
+#include <linux/module.h>
+
+#include "greybus.h"
+#include "gbphy.h"
+#include "spilib.h"
+
+static struct spilib_ops *spilib_ops;
+
+static int gb_spi_probe(struct gbphy_device *gbphy_dev,
+ const struct gbphy_device_id *id)
+{
+ struct gb_connection *connection;
+ int ret;
+
+ connection = gb_connection_create(gbphy_dev->bundle,
+
le16_to_cpu(gbphy_dev->cport_desc->id),
+ NULL);
+ if (IS_ERR(connection))
+ return PTR_ERR(connection);
+
+ ret = gb_connection_enable(connection);
+ if (ret)
+ goto exit_connection_destroy;
+
+ ret = gb_spilib_master_init(connection, &gbphy_dev->dev, spilib_ops);
+ if (ret)
+ goto exit_connection_disable;
+
+ gb_gbphy_set_data(gbphy_dev, connection);
+
+ gbphy_runtime_put_autosuspend(gbphy_dev);
+ return 0;
+
+exit_connection_disable:
+ gb_connection_disable(connection);
+exit_connection_destroy:
+ gb_connection_destroy(connection);
+
+ return ret;
+}
+
+static void gb_spi_remove(struct gbphy_device *gbphy_dev)
+{
+ struct gb_connection *connection = gb_gbphy_get_data(gbphy_dev);
+ int ret;
+
+ ret = gbphy_runtime_get_sync(gbphy_dev);
+ if (ret)
+ gbphy_runtime_get_noresume(gbphy_dev);
+
+ gb_spilib_master_exit(connection);
+ gb_connection_disable(connection);
+ gb_connection_destroy(connection);
+}
+
+static const struct gbphy_device_id gb_spi_id_table[] = {
+ { GBPHY_PROTOCOL(GREYBUS_PROTOCOL_SPI) },
+ { },
+};
+MODULE_DEVICE_TABLE(gbphy, gb_spi_id_table);
+
+static struct gbphy_driver spi_driver = {
+ .name = "spi",
+ .probe = gb_spi_probe,
+ .remove = gb_spi_remove,
+ .id_table = gb_spi_id_table,
+};
+
+module_gbphy_driver(spi_driver);
+MODULE_LICENSE("GPL v2");
--- /dev/null
+++ b/drivers/greybus/spilib.c
@@ -0,0 +1,565 @@
+/*
+ * Greybus SPI library
+ *
+ * Copyright 2014-2016 Google Inc.
+ * Copyright 2014-2016 Linaro Ltd.
+ *
+ * Released under the GPLv2 only.
+ */
+
+#include <linux/bitops.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+
+#include "greybus.h"
+#include "spilib.h"
+
+struct gb_spilib {
+ struct gb_connection *connection;
+ struct device *parent;
+ struct spi_transfer *first_xfer;
+ struct spi_transfer *last_xfer;
+ struct spilib_ops *ops;
+ u32 rx_xfer_offset;
+ u32 tx_xfer_offset;
+ u32 last_xfer_size;
+ unsigned int op_timeout;
+ u16 mode;
+ u16 flags;
+ u32 bits_per_word_mask;
+ u8 num_chipselect;
+ u32 min_speed_hz;
+ u32 max_speed_hz;
+};
+
+#define GB_SPI_STATE_MSG_DONE ((void *)0)
+#define GB_SPI_STATE_MSG_IDLE ((void *)1)
+#define GB_SPI_STATE_MSG_RUNNING ((void *)2)
+#define GB_SPI_STATE_OP_READY ((void *)3)
+#define GB_SPI_STATE_OP_DONE ((void *)4)
+#define GB_SPI_STATE_MSG_ERROR ((void *)-1)
+
+#define XFER_TIMEOUT_TOLERANCE 200
+
+static struct spi_master *get_master_from_spi(struct gb_spilib *spi)
+{
+ return gb_connection_get_data(spi->connection);
+}
+
+static int tx_header_fit_operation(u32 tx_size, u32 count, size_t data_max)
+{
+ size_t headers_size;
+
+ data_max -= sizeof(struct gb_spi_transfer_request);
+ headers_size = (count + 1) * sizeof(struct gb_spi_transfer);
+
+ return tx_size + headers_size > data_max ? 0 : 1;
+}
+
+static size_t calc_rx_xfer_size(u32 rx_size, u32 *tx_xfer_size, u32 len,
+ size_t data_max)
+{
+ size_t rx_xfer_size;
+
+ data_max -= sizeof(struct gb_spi_transfer_response);
+
+ if (rx_size + len > data_max)
+ rx_xfer_size = data_max - rx_size;
+ else
+ rx_xfer_size = len;
+
+ /* if this is a write_read, for symmetry read the same as write */
+ if (*tx_xfer_size && rx_xfer_size > *tx_xfer_size)
+ rx_xfer_size = *tx_xfer_size;
+ if (*tx_xfer_size && rx_xfer_size < *tx_xfer_size)
+ *tx_xfer_size = rx_xfer_size;
+
+ return rx_xfer_size;
+}
+
+static size_t calc_tx_xfer_size(u32 tx_size, u32 count, size_t len,
+ size_t data_max)
+{
+ size_t headers_size;
+
+ data_max -= sizeof(struct gb_spi_transfer_request);
+ headers_size = (count + 1) * sizeof(struct gb_spi_transfer);
+
+ if (tx_size + headers_size + len > data_max)
+ return data_max - (tx_size + sizeof(struct gb_spi_transfer));
+
+ return len;
+}
+
+static void clean_xfer_state(struct gb_spilib *spi)
+{
+ spi->first_xfer = NULL;
+ spi->last_xfer = NULL;
+ spi->rx_xfer_offset = 0;
+ spi->tx_xfer_offset = 0;
+ spi->last_xfer_size = 0;
+ spi->op_timeout = 0;
+}
+
+static bool is_last_xfer_done(struct gb_spilib *spi)
+{
+ struct spi_transfer *last_xfer = spi->last_xfer;
+
+ if ((spi->tx_xfer_offset + spi->last_xfer_size == last_xfer->len) ||
+ (spi->rx_xfer_offset + spi->last_xfer_size == last_xfer->len))
+ return true;
+
+ return false;
+}
+
+static int setup_next_xfer(struct gb_spilib *spi, struct spi_message *msg)
+{
+ struct spi_transfer *last_xfer = spi->last_xfer;
+
+ if (msg->state != GB_SPI_STATE_OP_DONE)
+ return 0;
+
+ /*
+ * if we transferred all content of the last transfer, reset values and
+ * check if this was the last transfer in the message
+ */
+ if (is_last_xfer_done(spi)) {
+ spi->tx_xfer_offset = 0;
+ spi->rx_xfer_offset = 0;
+ spi->op_timeout = 0;
+ if (last_xfer == list_last_entry(&msg->transfers,
+ struct spi_transfer,
+ transfer_list))
+ msg->state = GB_SPI_STATE_MSG_DONE;
+ else
+ spi->first_xfer = list_next_entry(last_xfer,
+ transfer_list);
+ return 0;
+ }
+
+ spi->first_xfer = last_xfer;
+ if (last_xfer->tx_buf)
+ spi->tx_xfer_offset += spi->last_xfer_size;
+
+ if (last_xfer->rx_buf)
+ spi->rx_xfer_offset += spi->last_xfer_size;
+
+ return 0;
+}
+
+static struct spi_transfer *get_next_xfer(struct spi_transfer *xfer,
+ struct spi_message *msg)
+{
+ if (xfer == list_last_entry(&msg->transfers, struct spi_transfer,
+ transfer_list))
+ return NULL;
+
+ return list_next_entry(xfer, transfer_list);
+}
+
+/* Routines to transfer data */
+static struct gb_operation *gb_spi_operation_create(struct gb_spilib *spi,
+ struct gb_connection *connection, struct spi_message *msg)
+{
+ struct gb_spi_transfer_request *request;
+ struct spi_device *dev = msg->spi;
+ struct spi_transfer *xfer;
+ struct gb_spi_transfer *gb_xfer;
+ struct gb_operation *operation;
+ u32 tx_size = 0, rx_size = 0, count = 0, xfer_len = 0, request_size;
+ u32 tx_xfer_size = 0, rx_xfer_size = 0, len;
+ u32 total_len = 0;
+ unsigned int xfer_timeout;
+ size_t data_max;
+ void *tx_data;
+
+ data_max = gb_operation_get_payload_size_max(connection);
+ xfer = spi->first_xfer;
+
+ /* Find number of transfers queued and tx/rx length in the message */
+
+ while (msg->state != GB_SPI_STATE_OP_READY) {
+ msg->state = GB_SPI_STATE_MSG_RUNNING;
+ spi->last_xfer = xfer;
+
+ if (!xfer->tx_buf && !xfer->rx_buf) {
+ dev_err(spi->parent,
+ "bufferless transfer, length %u\n", xfer->len);
+ msg->state = GB_SPI_STATE_MSG_ERROR;
+ return NULL;
+ }
+
+ tx_xfer_size = 0;
+ rx_xfer_size = 0;
+
+ if (xfer->tx_buf) {
+ len = xfer->len - spi->tx_xfer_offset;
+ if (!tx_header_fit_operation(tx_size, count, data_max))
+ break;
+ tx_xfer_size = calc_tx_xfer_size(tx_size, count,
+ len, data_max);
+ spi->last_xfer_size = tx_xfer_size;
+ }
+
+ if (xfer->rx_buf) {
+ len = xfer->len - spi->rx_xfer_offset;
+ rx_xfer_size = calc_rx_xfer_size(rx_size, &tx_xfer_size,
+ len, data_max);
+ spi->last_xfer_size = rx_xfer_size;
+ }
+
+ tx_size += tx_xfer_size;
+ rx_size += rx_xfer_size;
+
+ total_len += spi->last_xfer_size;
+ count++;
+
+ xfer = get_next_xfer(xfer, msg);
+ if (!xfer || total_len >= data_max)
+ msg->state = GB_SPI_STATE_OP_READY;
+ }
+
+ /*
+ * In addition to space for all message descriptors we need
+ * to have enough to hold all tx data.
+ */
+ request_size = sizeof(*request);
+ request_size += count * sizeof(*gb_xfer);
+ request_size += tx_size;
+
+ /* Response consists only of incoming data */
+ operation = gb_operation_create(connection, GB_SPI_TYPE_TRANSFER,
+ request_size, rx_size, GFP_KERNEL);
+ if (!operation)
+ return NULL;
+
+ request = operation->request->payload;
+ request->count = cpu_to_le16(count);
+ request->mode = dev->mode;
+ request->chip_select = dev->chip_select;
+
+ gb_xfer = &request->transfers[0];
+ tx_data = gb_xfer + count; /* place tx data after last gb_xfer */
+
+ /* Fill in the transfers array */
+ xfer = spi->first_xfer;
+ while (msg->state != GB_SPI_STATE_OP_DONE) {
+ if (xfer == spi->last_xfer)
+ xfer_len = spi->last_xfer_size;
+ else
+ xfer_len = xfer->len;
+
+ /* make sure we do not timeout in a slow transfer */
+ xfer_timeout = xfer_len * 8 * MSEC_PER_SEC / xfer->speed_hz;
+ xfer_timeout += GB_OPERATION_TIMEOUT_DEFAULT;
+
+ if (xfer_timeout > spi->op_timeout)
+ spi->op_timeout = xfer_timeout;
+
+ gb_xfer->speed_hz = cpu_to_le32(xfer->speed_hz);
+ gb_xfer->len = cpu_to_le32(xfer_len);
+ gb_xfer->delay_usecs = cpu_to_le16(xfer->delay_usecs);
+ gb_xfer->cs_change = xfer->cs_change;
+ gb_xfer->bits_per_word = xfer->bits_per_word;
+
+ /* Copy tx data */
+ if (xfer->tx_buf) {
+ gb_xfer->xfer_flags |= GB_SPI_XFER_WRITE;
+ memcpy(tx_data, xfer->tx_buf + spi->tx_xfer_offset,
+ xfer_len);
+ tx_data += xfer_len;
+ }
+
+ if (xfer->rx_buf)
+ gb_xfer->xfer_flags |= GB_SPI_XFER_READ;
+
+ if (xfer == spi->last_xfer) {
+ if (!is_last_xfer_done(spi))
+ gb_xfer->xfer_flags |= GB_SPI_XFER_INPROGRESS;
+ msg->state = GB_SPI_STATE_OP_DONE;
+ continue;
+ }
+
+ gb_xfer++;
+ xfer = get_next_xfer(xfer, msg);
+ }
+
+ msg->actual_length += total_len;
+
+ return operation;
+}
+
+static void gb_spi_decode_response(struct gb_spilib *spi,
+ struct spi_message *msg,
+ struct gb_spi_transfer_response *response)
+{
+ struct spi_transfer *xfer = spi->first_xfer;
+ void *rx_data = response->data;
+ u32 xfer_len;
+
+ while (xfer) {
+ /* Copy rx data */
+ if (xfer->rx_buf) {
+ if (xfer == spi->first_xfer)
+ xfer_len = xfer->len - spi->rx_xfer_offset;
+ else if (xfer == spi->last_xfer)
+ xfer_len = spi->last_xfer_size;
+ else
+ xfer_len = xfer->len;
+
+ memcpy(xfer->rx_buf + spi->rx_xfer_offset, rx_data,
+ xfer_len);
+ rx_data += xfer_len;
+ }
+
+ if (xfer == spi->last_xfer)
+ break;
+
+ xfer = list_next_entry(xfer, transfer_list);
+ }
+}
+
+static int gb_spi_transfer_one_message(struct spi_master *master,
+ struct spi_message *msg)
+{
+ struct gb_spilib *spi = spi_master_get_devdata(master);
+ struct gb_connection *connection = spi->connection;
+ struct gb_spi_transfer_response *response;
+ struct gb_operation *operation;
+ int ret = 0;
+
+ spi->first_xfer = list_first_entry_or_null(&msg->transfers,
+ struct spi_transfer,
+ transfer_list);
+ if (!spi->first_xfer) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ msg->state = GB_SPI_STATE_MSG_IDLE;
+
+ while (msg->state != GB_SPI_STATE_MSG_DONE &&
+ msg->state != GB_SPI_STATE_MSG_ERROR) {
+ operation = gb_spi_operation_create(spi, connection, msg);
+ if (!operation) {
+ msg->state = GB_SPI_STATE_MSG_ERROR;
+ ret = -EINVAL;
+ continue;
+ }
+
+ ret = gb_operation_request_send_sync_timeout(operation,
+ spi->op_timeout);
+ if (!ret) {
+ response = operation->response->payload;
+ if (response)
+ gb_spi_decode_response(spi, msg, response);
+ } else {
+ dev_err(spi->parent,
+ "transfer operation failed: %d\n", ret);
+ msg->state = GB_SPI_STATE_MSG_ERROR;
+ }
+
+ gb_operation_put(operation);
+ setup_next_xfer(spi, msg);
+ }
+
+out:
+ msg->status = ret;
+ clean_xfer_state(spi);
+ spi_finalize_current_message(master);
+
+ return ret;
+}
+
+static int gb_spi_prepare_transfer_hardware(struct spi_master *master)
+{
+ struct gb_spilib *spi = spi_master_get_devdata(master);
+
+ return spi->ops->prepare_transfer_hardware(spi->parent);
+}
+
+static int gb_spi_unprepare_transfer_hardware(struct spi_master *master)
+{
+ struct gb_spilib *spi = spi_master_get_devdata(master);
+
+ spi->ops->unprepare_transfer_hardware(spi->parent);
+
+ return 0;
+}
+
+static int gb_spi_setup(struct spi_device *spi)
+{
+ /* Nothing to do for now */
+ return 0;
+}
+
+static void gb_spi_cleanup(struct spi_device *spi)
+{
+ /* Nothing to do for now */
+}
+
+/* Routines to get controller information */
+
+/*
+ * Map Greybus spi mode bits/flags/bpw into Linux ones.
+ * All bits are same for now and so these macro's return same values.
+ */
+#define gb_spi_mode_map(mode) mode
+#define gb_spi_flags_map(flags) flags
+
+static int gb_spi_get_master_config(struct gb_spilib *spi)
+{
+ struct gb_spi_master_config_response response;
+ u16 mode, flags;
+ int ret;
+
+ ret = gb_operation_sync(spi->connection, GB_SPI_TYPE_MASTER_CONFIG,
+ NULL, 0, &response, sizeof(response));
+ if (ret < 0)
+ return ret;
+
+ mode = le16_to_cpu(response.mode);
+ spi->mode = gb_spi_mode_map(mode);
+
+ flags = le16_to_cpu(response.flags);
+ spi->flags = gb_spi_flags_map(flags);
+
+ spi->bits_per_word_mask = le32_to_cpu(response.bits_per_word_mask);
+ spi->num_chipselect = response.num_chipselect;
+
+ spi->min_speed_hz = le32_to_cpu(response.min_speed_hz);
+ spi->max_speed_hz = le32_to_cpu(response.max_speed_hz);
+
+ return 0;
+}
+
+static int gb_spi_setup_device(struct gb_spilib *spi, u8 cs)
+{
+ struct spi_master *master = get_master_from_spi(spi);
+ struct gb_spi_device_config_request request;
+ struct gb_spi_device_config_response response;
+ struct spi_board_info spi_board = { {0} };
+ struct spi_device *spidev;
+ int ret;
+ u8 dev_type;
+
+ request.chip_select = cs;
+
+ ret = gb_operation_sync(spi->connection, GB_SPI_TYPE_DEVICE_CONFIG,
+ &request, sizeof(request),
+ &response, sizeof(response));
+ if (ret < 0)
+ return ret;
+
+ dev_type = response.device_type;
+
+ if (dev_type == GB_SPI_SPI_DEV)
+ strlcpy(spi_board.modalias, "spidev",
+ sizeof(spi_board.modalias));
+ else if (dev_type == GB_SPI_SPI_NOR)
+ strlcpy(spi_board.modalias, "spi-nor",
+ sizeof(spi_board.modalias));
+ else if (dev_type == GB_SPI_SPI_MODALIAS)
+ memcpy(spi_board.modalias, response.name,
+ sizeof(spi_board.modalias));
+ else
+ return -EINVAL;
+
+ spi_board.mode = le16_to_cpu(response.mode);
+ spi_board.bus_num = master->bus_num;
+ spi_board.chip_select = cs;
+ spi_board.max_speed_hz = le32_to_cpu(response.max_speed_hz);
+
+ spidev = spi_new_device(master, &spi_board);
+ if (!spidev)
+ return -EINVAL;
+
+ return 0;
+}
+
+int gb_spilib_master_init(struct gb_connection *connection, struct device *dev,
+ struct spilib_ops *ops)
+{
+ struct gb_spilib *spi;
+ struct spi_master *master;
+ int ret;
+ u8 i;
+
+ /* Allocate master with space for data */
+ master = spi_alloc_master(dev, sizeof(*spi));
+ if (!master) {
+ dev_err(dev, "cannot alloc SPI master\n");
+ return -ENOMEM;
+ }
+
+ spi = spi_master_get_devdata(master);
+ spi->connection = connection;
+ gb_connection_set_data(connection, master);
+ spi->parent = dev;
+ spi->ops = ops;
+
+ /* get master configuration */
+ ret = gb_spi_get_master_config(spi);
+ if (ret)
+ goto exit_spi_put;
+
+ master->bus_num = -1; /* Allow spi-core to allocate it dynamically */
+ master->num_chipselect = spi->num_chipselect;
+ master->mode_bits = spi->mode;
+ master->flags = spi->flags;
+ master->bits_per_word_mask = spi->bits_per_word_mask;
+
+ /* Attach methods */
+ master->cleanup = gb_spi_cleanup;
+ master->setup = gb_spi_setup;
+ master->transfer_one_message = gb_spi_transfer_one_message;
+
+ if (ops && ops->prepare_transfer_hardware) {
+ master->prepare_transfer_hardware =
+ gb_spi_prepare_transfer_hardware;
+ }
+
+ if (ops && ops->unprepare_transfer_hardware) {
+ master->unprepare_transfer_hardware =
+ gb_spi_unprepare_transfer_hardware;
+ }
+
+ master->auto_runtime_pm = true;
+
+ ret = spi_register_master(master);
+ if (ret < 0)
+ goto exit_spi_put;
+
+ /* now, fetch the devices configuration */
+ for (i = 0; i < spi->num_chipselect; i++) {
+ ret = gb_spi_setup_device(spi, i);
+ if (ret < 0) {
+ dev_err(dev, "failed to allocate spi device %d: %d\n",
+ i, ret);
+ goto exit_spi_unregister;
+ }
+ }
+
+ return 0;
+
+exit_spi_unregister:
+ spi_unregister_master(master);
+exit_spi_put:
+ spi_master_put(master);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(gb_spilib_master_init);
+
+void gb_spilib_master_exit(struct gb_connection *connection)
+{
+ struct spi_master *master = gb_connection_get_data(connection);
+
+ spi_unregister_master(master);
+ spi_master_put(master);
+}
+EXPORT_SYMBOL_GPL(gb_spilib_master_exit);
+
+MODULE_LICENSE("GPL v2");
--- /dev/null
+++ b/drivers/greybus/spilib.h
@@ -0,0 +1,24 @@
+/*
+ * Greybus SPI library header
+ *
+ * copyright 2016 google inc.
+ * copyright 2016 linaro ltd.
+ *
+ * released under the gplv2 only.
+ */
+
+#ifndef __SPILIB_H
+#define __SPILIB_H
+
+struct device;
+struct gb_connection;
+
+struct spilib_ops {
+ int (*prepare_transfer_hardware)(struct device *dev);
+ void (*unprepare_transfer_hardware)(struct device *dev);
+};
+
+int gb_spilib_master_init(struct gb_connection *connection, struct device
*dev, struct spilib_ops *ops);
+void gb_spilib_master_exit(struct gb_connection *connection);
+
+#endif /* __SPILIB_H */
