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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-05 14:50:51 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-05 14:50:51 -0700 |
commit | 41844e36206be90cd4d962ea49b0abc3612a99d0 (patch) | |
tree | ce0b3a3403bc6abdb28f52779d0d7b57a51a5c86 /drivers/staging/greybus/spilib.c | |
parent | 5691f0e9a3e7855832d5fd094801bf600347c2d0 (diff) | |
parent | fc1e2c8ea85e109acf09e74789e9b852f6eed251 (diff) | |
download | op-kernel-dev-41844e36206be90cd4d962ea49b0abc3612a99d0.zip op-kernel-dev-41844e36206be90cd4d962ea49b0abc3612a99d0.tar.gz |
Merge tag 'staging-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging and IIO updates from Greg KH:
"Here is the big staging and IIO driver pull request for 4.9-rc1.
There are a lot of patches in here, the majority due to the
drivers/staging/greybus/ subsystem being merged in with full
development history that went back a few years, in order to preserve
the work that those developers did over time.
Lots and lots of tiny cleanups happened in the tree as well, due to
the Outreachy application process and lots of other developers showing
up for the first time to clean code up. Along with those changes, we
deleted a wireless driver, and added a raspberrypi driver (currently
marked broken), and lots of new iio drivers.
Overall the tree still shrunk with more lines removed than added,
about 10 thousand lines removed in total. Full details are in the very
long shortlog below.
All of this has been in the linux-next tree with no issues. There will
be some merge problems with other subsystem trees, but those are all
minor problems and shouldn't be hard to work out when they happen
(MAINTAINERS and some lustre build problems with the IB tree)"
And furter from me asking for clarification about greybus:
"Right now there is a phone from Motorola shipping with this code (a
slightly older version, but the same tree), so even though Ara is not
alive in the same form, the functionality is happening. We are working
with the developers of that phone to merge the newer stuff in with
their fork so they can use the upstream version in future versions of
their phone product line.
Toshiba has at least one chip shipping in their catalog that
needs/uses this protocol over a Unipro link, and rumor has it that
there might be more in the future.
There are also other users of the greybus protocols, there is a talk
next week at ELC that shows how it is being used across a network
connection to control a device, and previous ELC talks have showed the
protocol stack being used over USB to drive embedded Linux boards.
I've also talked to some people who are starting to work to add a host
controller driver to control arduinos as the greybus PHY protocols are
very useful to control a serial/i2c/spio/whatever device across a
random physical link, as it is a way to have a self-describing device
be attached to a host without needing manual configuration.
So yes, people are using it, and there is still the chance that it
will show up in a phone/laptop/tablet/whatever from Google in the
future as well, the tech isn't dead, even if the original large phone
project happens to be"
* tag 'staging-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (3703 commits)
Staging: fbtft: Fix bug in fbtft-core
staging: rtl8188eu: fix double unlock error in rtw_resume_process()
staging:r8188eu: remove GEN_MLME_EXT_HANDLER macro
staging:r8188eu: remove GEN_DRV_CMD_HANDLER macro
staging:r8188eu: remove GEN_EVT_CODE macro
staging:r8188eu: remove GEN_CMD_CODE macro
staging:r8188eu: remove pkt_newalloc member of the recv_buf structure
staging:r8188eu: remove rtw_handle_dualmac declaration
staging:r8188eu: remove (RGTRY|BSSID)_(OFT|SZ) macros
staging:r8188eu: change rtl8188e_process_phy_info function argument type
Staging: fsl-mc: Remove blank lines
Staging: fsl-mc: Fix unaligned * in block comments
Staging: comedi: Align the * in block comments
Staging : ks7010 : Fix block comments warninig
Staging: vt6655: Remove explicit NULL comparison using Coccinelle
staging: rtl8188eu: core: rtw_xmit: Use macros instead of constants
staging: rtl8188eu: core: rtw_xmit: Move constant of the right side
staging: dgnc: Fix lines longer than 80 characters
Staging: dgnc: constify attribute_group structures
Staging: most: hdm-dim2: constify attribute_group structures
...
Diffstat (limited to 'drivers/staging/greybus/spilib.c')
-rw-r--r-- | drivers/staging/greybus/spilib.c | 565 |
1 files changed, 565 insertions, 0 deletions
diff --git a/drivers/staging/greybus/spilib.c b/drivers/staging/greybus/spilib.c new file mode 100644 index 0000000..e97b191 --- /dev/null +++ b/drivers/staging/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"); |