diff options
Diffstat (limited to 'drivers/spi/spi-bitbang.c')
| -rw-r--r-- | drivers/spi/spi-bitbang.c | 182 |
1 files changed, 94 insertions, 88 deletions
diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c index ecd44016c197..ebe18f0b5d23 100644 --- a/drivers/spi/spi-bitbang.c +++ b/drivers/spi/spi-bitbang.c @@ -1,6 +1,6 @@ // SPDX-License-Identifier: GPL-2.0-or-later /* - * polling/bitbanging SPI master controller driver utilities + * Polling/bitbanging SPI host controller controller driver utilities */ #include <linux/spinlock.h> @@ -11,6 +11,7 @@ #include <linux/errno.h> #include <linux/platform_device.h> #include <linux/slab.h> +#include <linux/time64.h> #include <linux/spi/spi.h> #include <linux/spi/spi_bitbang.h> @@ -37,104 +38,106 @@ * working quickly, or testing for differences that aren't speed related. */ +typedef unsigned int (*spi_bb_txrx_bufs_fn)(struct spi_device *, spi_bb_txrx_word_fn, + unsigned int, struct spi_transfer *, + unsigned int); + struct spi_bitbang_cs { - unsigned nsecs; /* (clock cycle time)/2 */ - u32 (*txrx_word)(struct spi_device *spi, unsigned nsecs, - u32 word, u8 bits, unsigned flags); - unsigned (*txrx_bufs)(struct spi_device *, - u32 (*txrx_word)( - struct spi_device *spi, - unsigned nsecs, - u32 word, u8 bits, - unsigned flags), - unsigned, struct spi_transfer *, - unsigned); + unsigned int nsecs; /* (clock cycle time) / 2 */ + spi_bb_txrx_word_fn txrx_word; + spi_bb_txrx_bufs_fn txrx_bufs; }; -static unsigned bitbang_txrx_8( - struct spi_device *spi, - u32 (*txrx_word)(struct spi_device *spi, - unsigned nsecs, - u32 word, u8 bits, - unsigned flags), - unsigned ns, +static unsigned int bitbang_txrx_8(struct spi_device *spi, + spi_bb_txrx_word_fn txrx_word, + unsigned int ns, struct spi_transfer *t, - unsigned flags -) + unsigned int flags) { - unsigned bits = t->bits_per_word; - unsigned count = t->len; + struct spi_bitbang *bitbang; + unsigned int bits = t->bits_per_word; + unsigned int count = t->len; const u8 *tx = t->tx_buf; u8 *rx = t->rx_buf; + bitbang = spi_controller_get_devdata(spi->controller); while (likely(count > 0)) { u8 word = 0; if (tx) word = *tx++; + else + word = spi->mode & SPI_MOSI_IDLE_HIGH ? 0xFF : 0; word = txrx_word(spi, ns, word, bits, flags); if (rx) *rx++ = word; count -= 1; } + if (bitbang->set_mosi_idle) + bitbang->set_mosi_idle(spi); + return t->len - count; } -static unsigned bitbang_txrx_16( - struct spi_device *spi, - u32 (*txrx_word)(struct spi_device *spi, - unsigned nsecs, - u32 word, u8 bits, - unsigned flags), - unsigned ns, +static unsigned int bitbang_txrx_16(struct spi_device *spi, + spi_bb_txrx_word_fn txrx_word, + unsigned int ns, struct spi_transfer *t, - unsigned flags -) + unsigned int flags) { - unsigned bits = t->bits_per_word; - unsigned count = t->len; + struct spi_bitbang *bitbang; + unsigned int bits = t->bits_per_word; + unsigned int count = t->len; const u16 *tx = t->tx_buf; u16 *rx = t->rx_buf; + bitbang = spi_controller_get_devdata(spi->controller); while (likely(count > 1)) { u16 word = 0; if (tx) word = *tx++; + else + word = spi->mode & SPI_MOSI_IDLE_HIGH ? 0xFFFF : 0; word = txrx_word(spi, ns, word, bits, flags); if (rx) *rx++ = word; count -= 2; } + if (bitbang->set_mosi_idle) + bitbang->set_mosi_idle(spi); + return t->len - count; } -static unsigned bitbang_txrx_32( - struct spi_device *spi, - u32 (*txrx_word)(struct spi_device *spi, - unsigned nsecs, - u32 word, u8 bits, - unsigned flags), - unsigned ns, +static unsigned int bitbang_txrx_32(struct spi_device *spi, + spi_bb_txrx_word_fn txrx_word, + unsigned int ns, struct spi_transfer *t, - unsigned flags -) + unsigned int flags) { - unsigned bits = t->bits_per_word; - unsigned count = t->len; + struct spi_bitbang *bitbang; + unsigned int bits = t->bits_per_word; + unsigned int count = t->len; const u32 *tx = t->tx_buf; u32 *rx = t->rx_buf; + bitbang = spi_controller_get_devdata(spi->controller); while (likely(count > 3)) { u32 word = 0; if (tx) word = *tx++; + else + word = spi->mode & SPI_MOSI_IDLE_HIGH ? 0xFFFFFFFF : 0; word = txrx_word(spi, ns, word, bits, flags); if (rx) *rx++ = word; count -= 4; } + if (bitbang->set_mosi_idle) + bitbang->set_mosi_idle(spi); + return t->len - count; } @@ -168,8 +171,8 @@ int spi_bitbang_setup_transfer(struct spi_device *spi, struct spi_transfer *t) if (!hz) hz = spi->max_speed_hz; if (hz) { - cs->nsecs = (1000000000/2) / hz; - if (cs->nsecs > (MAX_UDELAY_MS * 1000 * 1000)) + cs->nsecs = (NSEC_PER_SEC / 2) / hz; + if (cs->nsecs > (MAX_UDELAY_MS * NSEC_PER_MSEC)) return -EINVAL; } @@ -187,7 +190,7 @@ int spi_bitbang_setup(struct spi_device *spi) bool initial_setup = false; int retval; - bitbang = spi_master_get_devdata(spi->master); + bitbang = spi_controller_get_devdata(spi->controller); if (!cs) { cs = kzalloc(sizeof(*cs), GFP_KERNEL); @@ -210,6 +213,9 @@ int spi_bitbang_setup(struct spi_device *spi) goto err_free; } + if (bitbang->set_mosi_idle) + bitbang->set_mosi_idle(spi); + dev_dbg(&spi->dev, "%s, %u nsec/bit\n", __func__, 2 * cs->nsecs); return 0; @@ -233,10 +239,10 @@ EXPORT_SYMBOL_GPL(spi_bitbang_cleanup); static int spi_bitbang_bufs(struct spi_device *spi, struct spi_transfer *t) { struct spi_bitbang_cs *cs = spi->controller_state; - unsigned nsecs = cs->nsecs; + unsigned int nsecs = cs->nsecs; struct spi_bitbang *bitbang; - bitbang = spi_master_get_devdata(spi->master); + bitbang = spi_controller_get_devdata(spi->controller); if (bitbang->set_line_direction) { int err; @@ -246,7 +252,7 @@ static int spi_bitbang_bufs(struct spi_device *spi, struct spi_transfer *t) } if (spi->mode & SPI_3WIRE) { - unsigned flags; + unsigned int flags; flags = t->tx_buf ? SPI_CONTROLLER_NO_RX : SPI_CONTROLLER_NO_TX; return cs->txrx_bufs(spi, cs->txrx_word, nsecs, t, flags); @@ -268,11 +274,11 @@ static int spi_bitbang_bufs(struct spi_device *spi, struct spi_transfer *t) * transfer-at-a-time ones to leverage dma or fifo hardware. */ -static int spi_bitbang_prepare_hardware(struct spi_master *spi) +static int spi_bitbang_prepare_hardware(struct spi_controller *spi) { struct spi_bitbang *bitbang; - bitbang = spi_master_get_devdata(spi); + bitbang = spi_controller_get_devdata(spi); mutex_lock(&bitbang->lock); bitbang->busy = 1; @@ -281,11 +287,11 @@ static int spi_bitbang_prepare_hardware(struct spi_master *spi) return 0; } -static int spi_bitbang_transfer_one(struct spi_master *master, +static int spi_bitbang_transfer_one(struct spi_controller *ctlr, struct spi_device *spi, struct spi_transfer *transfer) { - struct spi_bitbang *bitbang = spi_master_get_devdata(master); + struct spi_bitbang *bitbang = spi_controller_get_devdata(ctlr); int status = 0; if (bitbang->setup_transfer) { @@ -303,16 +309,16 @@ static int spi_bitbang_transfer_one(struct spi_master *master, status = -EREMOTEIO; out: - spi_finalize_current_transfer(master); + spi_finalize_current_transfer(ctlr); return status; } -static int spi_bitbang_unprepare_hardware(struct spi_master *spi) +static int spi_bitbang_unprepare_hardware(struct spi_controller *spi) { struct spi_bitbang *bitbang; - bitbang = spi_master_get_devdata(spi); + bitbang = spi_controller_get_devdata(spi); mutex_lock(&bitbang->lock); bitbang->busy = 0; @@ -323,7 +329,7 @@ static int spi_bitbang_unprepare_hardware(struct spi_master *spi) static void spi_bitbang_set_cs(struct spi_device *spi, bool enable) { - struct spi_bitbang *bitbang = spi_master_get_devdata(spi->master); + struct spi_bitbang *bitbang = spi_controller_get_devdata(spi->controller); /* SPI core provides CS high / low, but bitbang driver * expects CS active @@ -341,10 +347,10 @@ static void spi_bitbang_set_cs(struct spi_device *spi, bool enable) int spi_bitbang_init(struct spi_bitbang *bitbang) { - struct spi_master *master = bitbang->master; + struct spi_controller *ctlr = bitbang->ctlr; bool custom_cs; - if (!master) + if (!ctlr) return -EINVAL; /* * We only need the chipselect callback if we are actually using it. @@ -352,39 +358,39 @@ int spi_bitbang_init(struct spi_bitbang *bitbang) * SPI_CONTROLLER_GPIO_SS flag is set, we always need to call the * driver-specific chipselect routine. */ - custom_cs = (!master->use_gpio_descriptors || - (master->flags & SPI_CONTROLLER_GPIO_SS)); + custom_cs = (!ctlr->use_gpio_descriptors || + (ctlr->flags & SPI_CONTROLLER_GPIO_SS)); if (custom_cs && !bitbang->chipselect) return -EINVAL; mutex_init(&bitbang->lock); - if (!master->mode_bits) - master->mode_bits = SPI_CPOL | SPI_CPHA | bitbang->flags; + if (!ctlr->mode_bits) + ctlr->mode_bits = SPI_CPOL | SPI_CPHA | bitbang->flags; - if (master->transfer || master->transfer_one_message) + if (ctlr->transfer || ctlr->transfer_one_message) return -EINVAL; - master->prepare_transfer_hardware = spi_bitbang_prepare_hardware; - master->unprepare_transfer_hardware = spi_bitbang_unprepare_hardware; - master->transfer_one = spi_bitbang_transfer_one; + ctlr->prepare_transfer_hardware = spi_bitbang_prepare_hardware; + ctlr->unprepare_transfer_hardware = spi_bitbang_unprepare_hardware; + ctlr->transfer_one = spi_bitbang_transfer_one; /* * When using GPIO descriptors, the ->set_cs() callback doesn't even * get called unless SPI_CONTROLLER_GPIO_SS is set. */ if (custom_cs) - master->set_cs = spi_bitbang_set_cs; + ctlr->set_cs = spi_bitbang_set_cs; if (!bitbang->txrx_bufs) { bitbang->use_dma = 0; bitbang->txrx_bufs = spi_bitbang_bufs; - if (!master->setup) { + if (!ctlr->setup) { if (!bitbang->setup_transfer) bitbang->setup_transfer = spi_bitbang_setup_transfer; - master->setup = spi_bitbang_setup; - master->cleanup = spi_bitbang_cleanup; + ctlr->setup = spi_bitbang_setup; + ctlr->cleanup = spi_bitbang_cleanup; } } @@ -393,12 +399,12 @@ int spi_bitbang_init(struct spi_bitbang *bitbang) EXPORT_SYMBOL_GPL(spi_bitbang_init); /** - * spi_bitbang_start - start up a polled/bitbanging SPI master driver + * spi_bitbang_start - start up a polled/bitbanging SPI host controller driver * @bitbang: driver handle * * Caller should have zero-initialized all parts of the structure, and then - * provided callbacks for chip selection and I/O loops. If the master has - * a transfer method, its final step should call spi_bitbang_transfer; or, + * provided callbacks for chip selection and I/O loops. If the host controller has + * a transfer method, its final step should call spi_bitbang_transfer(); or, * that's the default if the transfer routine is not initialized. It should * also set up the bus number and number of chipselects. * @@ -406,23 +412,23 @@ EXPORT_SYMBOL_GPL(spi_bitbang_init); * hardware that basically exposes a shift register) or per-spi_transfer * (which takes better advantage of hardware like fifos or DMA engines). * - * Drivers using per-word I/O loops should use (or call) spi_bitbang_setup, - * spi_bitbang_cleanup and spi_bitbang_setup_transfer to handle those spi - * master methods. Those methods are the defaults if the bitbang->txrx_bufs + * Drivers using per-word I/O loops should use (or call) spi_bitbang_setup(), + * spi_bitbang_cleanup() and spi_bitbang_setup_transfer() to handle those SPI + * host controller methods. Those methods are the defaults if the bitbang->txrx_bufs * routine isn't initialized. * - * This routine registers the spi_master, which will process requests in a + * This routine registers the spi_controller, which will process requests in a * dedicated task, keeping IRQs unblocked most of the time. To stop * processing those requests, call spi_bitbang_stop(). * - * On success, this routine will take a reference to master. The caller is - * responsible for calling spi_bitbang_stop() to decrement the reference and - * spi_master_put() as counterpart of spi_alloc_master() to prevent a memory + * On success, this routine will take a reference to the controller. The caller + * is responsible for calling spi_bitbang_stop() to decrement the reference and + * spi_controller_put() as counterpart of spi_alloc_host() to prevent a memory * leak. */ int spi_bitbang_start(struct spi_bitbang *bitbang) { - struct spi_master *master = bitbang->master; + struct spi_controller *ctlr = bitbang->ctlr; int ret; ret = spi_bitbang_init(bitbang); @@ -432,9 +438,9 @@ int spi_bitbang_start(struct spi_bitbang *bitbang) /* driver may get busy before register() returns, especially * if someone registered boardinfo for devices */ - ret = spi_register_master(spi_master_get(master)); + ret = spi_register_controller(spi_controller_get(ctlr)); if (ret) - spi_master_put(master); + spi_controller_put(ctlr); return ret; } @@ -445,9 +451,9 @@ EXPORT_SYMBOL_GPL(spi_bitbang_start); */ void spi_bitbang_stop(struct spi_bitbang *bitbang) { - spi_unregister_master(bitbang->master); + spi_unregister_controller(bitbang->ctlr); } EXPORT_SYMBOL_GPL(spi_bitbang_stop); MODULE_LICENSE("GPL"); - +MODULE_DESCRIPTION("Utilities for Bitbanging SPI host controllers"); |