diff options
| -rw-r--r-- | drivers/spi/spi-atmel.c | 8 | ||||
| -rw-r--r-- | drivers/spi/spi-bcm2835.c | 391 | ||||
| -rw-r--r-- | drivers/spi/spi-bcm53xx.c | 4 | ||||
| -rw-r--r-- | drivers/spi/spi-bitbang-txrx.h | 18 | ||||
| -rw-r--r-- | drivers/spi/spi.c | 3 | ||||
| -rw-r--r-- | include/linux/spi/spi.h | 4 |
6 files changed, 283 insertions, 145 deletions
diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c index 06de34001c66..a2f40b1b2225 100644 --- a/drivers/spi/spi-atmel.c +++ b/drivers/spi/spi-atmel.c @@ -180,11 +180,17 @@ | SPI_BF(name, value)) /* Register access macros */ +#ifdef CONFIG_AVR32 #define spi_readl(port, reg) \ __raw_readl((port)->regs + SPI_##reg) #define spi_writel(port, reg, value) \ __raw_writel((value), (port)->regs + SPI_##reg) - +#else +#define spi_readl(port, reg) \ + readl_relaxed((port)->regs + SPI_##reg) +#define spi_writel(port, reg, value) \ + writel_relaxed((value), (port)->regs + SPI_##reg) +#endif /* use PIO for small transfers, avoiding DMA setup/teardown overhead and * cache operations; better heuristics consider wordsize and bitrate. */ diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c index 419a782ab6d5..f63864a893c5 100644 --- a/drivers/spi/spi-bcm2835.c +++ b/drivers/spi/spi-bcm2835.c @@ -3,6 +3,7 @@ * * Copyright (C) 2012 Chris Boot * Copyright (C) 2013 Stephen Warren + * Copyright (C) 2015 Martin Sperl * * This driver is inspired by: * spi-ath79.c, Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org> @@ -29,6 +30,7 @@ #include <linux/module.h> #include <linux/of.h> #include <linux/of_irq.h> +#include <linux/of_gpio.h> #include <linux/of_device.h> #include <linux/spi/spi.h> @@ -66,8 +68,10 @@ #define BCM2835_SPI_CS_CS_10 0x00000002 #define BCM2835_SPI_CS_CS_01 0x00000001 -#define BCM2835_SPI_TIMEOUT_MS 30000 -#define BCM2835_SPI_MODE_BITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_NO_CS) +#define BCM2835_SPI_POLLING_LIMIT_US 30 +#define BCM2835_SPI_TIMEOUT_MS 30000 +#define BCM2835_SPI_MODE_BITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH \ + | SPI_NO_CS | SPI_3WIRE) #define DRV_NAME "spi-bcm2835" @@ -75,10 +79,10 @@ struct bcm2835_spi { void __iomem *regs; struct clk *clk; int irq; - struct completion done; const u8 *tx_buf; u8 *rx_buf; - int len; + int tx_len; + int rx_len; }; static inline u32 bcm2835_rd(struct bcm2835_spi *bs, unsigned reg) @@ -91,205 +95,315 @@ static inline void bcm2835_wr(struct bcm2835_spi *bs, unsigned reg, u32 val) writel(val, bs->regs + reg); } -static inline void bcm2835_rd_fifo(struct bcm2835_spi *bs, int len) +static inline void bcm2835_rd_fifo(struct bcm2835_spi *bs) { u8 byte; - while (len--) { + while ((bs->rx_len) && + (bcm2835_rd(bs, BCM2835_SPI_CS) & BCM2835_SPI_CS_RXD)) { byte = bcm2835_rd(bs, BCM2835_SPI_FIFO); if (bs->rx_buf) *bs->rx_buf++ = byte; + bs->rx_len--; } } -static inline void bcm2835_wr_fifo(struct bcm2835_spi *bs, int len) +static inline void bcm2835_wr_fifo(struct bcm2835_spi *bs) { u8 byte; - if (len > bs->len) - len = bs->len; - - while (len--) { + while ((bs->tx_len) && + (bcm2835_rd(bs, BCM2835_SPI_CS) & BCM2835_SPI_CS_TXD)) { byte = bs->tx_buf ? *bs->tx_buf++ : 0; bcm2835_wr(bs, BCM2835_SPI_FIFO, byte); - bs->len--; + bs->tx_len--; } } +static void bcm2835_spi_reset_hw(struct spi_master *master) +{ + struct bcm2835_spi *bs = spi_master_get_devdata(master); + u32 cs = bcm2835_rd(bs, BCM2835_SPI_CS); + + /* Disable SPI interrupts and transfer */ + cs &= ~(BCM2835_SPI_CS_INTR | + BCM2835_SPI_CS_INTD | + BCM2835_SPI_CS_TA); + /* and reset RX/TX FIFOS */ + cs |= BCM2835_SPI_CS_CLEAR_RX | BCM2835_SPI_CS_CLEAR_TX; + + /* and reset the SPI_HW */ + bcm2835_wr(bs, BCM2835_SPI_CS, cs); +} + static irqreturn_t bcm2835_spi_interrupt(int irq, void *dev_id) { struct spi_master *master = dev_id; struct bcm2835_spi *bs = spi_master_get_devdata(master); - u32 cs = bcm2835_rd(bs, BCM2835_SPI_CS); - /* - * RXR - RX needs Reading. This means 12 (or more) bytes have been - * transmitted and hence 12 (or more) bytes have been received. - * - * The FIFO is 16-bytes deep. We check for this interrupt to keep the - * FIFO full; we have a 4-byte-time buffer for IRQ latency. We check - * this before DONE (TX empty) just in case we delayed processing this - * interrupt for some reason. - * - * We only check for this case if we have more bytes to TX; at the end - * of the transfer, we ignore this pipelining optimization, and let - * bcm2835_spi_finish_transfer() drain the RX FIFO. + /* Read as many bytes as possible from FIFO */ + bcm2835_rd_fifo(bs); + /* Write as many bytes as possible to FIFO */ + bcm2835_wr_fifo(bs); + + /* based on flags decide if we can finish the transfer */ + if (bcm2835_rd(bs, BCM2835_SPI_CS) & BCM2835_SPI_CS_DONE) { + /* Transfer complete - reset SPI HW */ + bcm2835_spi_reset_hw(master); + /* wake up the framework */ + complete(&master->xfer_completion); + } + + return IRQ_HANDLED; +} + +static int bcm2835_spi_transfer_one_poll(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *tfr, + u32 cs, + unsigned long xfer_time_us) +{ + struct bcm2835_spi *bs = spi_master_get_devdata(master); + unsigned long timeout = jiffies + + max(4 * xfer_time_us * HZ / 1000000, 2uL); + + /* enable HW block without interrupts */ + bcm2835_wr(bs, BCM2835_SPI_CS, cs | BCM2835_SPI_CS_TA); + + /* set timeout to 4x the expected time, or 2 jiffies */ + /* loop until finished the transfer */ + while (bs->rx_len) { + /* read from fifo as much as possible */ + bcm2835_rd_fifo(bs); + /* fill in tx fifo as much as possible */ + bcm2835_wr_fifo(bs); + /* if we still expect some data after the read, + * check for a possible timeout + */ + if (bs->rx_len && time_after(jiffies, timeout)) { + /* Transfer complete - reset SPI HW */ + bcm2835_spi_reset_hw(master); + /* and return timeout */ + return -ETIMEDOUT; + } + } + + /* Transfer complete - reset SPI HW */ + bcm2835_spi_reset_hw(master); + /* and return without waiting for completion */ + return 0; +} + +static int bcm2835_spi_transfer_one_irq(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *tfr, + u32 cs) +{ + struct bcm2835_spi *bs = spi_master_get_devdata(master); + + /* fill in fifo if we have gpio-cs + * note that there have been rare events where the native-CS + * flapped for <1us which may change the behaviour + * with gpio-cs this does not happen, so it is implemented + * only for this case */ - if (bs->len && (cs & BCM2835_SPI_CS_RXR)) { - /* Read 12 bytes of data */ - bcm2835_rd_fifo(bs, 12); - - /* Write up to 12 bytes */ - bcm2835_wr_fifo(bs, 12); - - /* - * We must have written something to the TX FIFO due to the - * bs->len check above, so cannot be DONE. Hence, return - * early. Note that DONE could also be set if we serviced an - * RXR interrupt really late. + if (gpio_is_valid(spi->cs_gpio)) { + /* enable HW block, but without interrupts enabled + * this would triggern an immediate interrupt */ - return IRQ_HANDLED; + bcm2835_wr(bs, BCM2835_SPI_CS, + cs | BCM2835_SPI_CS_TA); + /* fill in tx fifo as much as possible */ + bcm2835_wr_fifo(bs); } /* - * DONE - TX empty. This occurs when we first enable the transfer - * since we do not pre-fill the TX FIFO. At any other time, given that - * we refill the TX FIFO above based on RXR, and hence ignore DONE if - * RXR is set, DONE really does mean end-of-transfer. + * Enable the HW block. This will immediately trigger a DONE (TX + * empty) interrupt, upon which we will fill the TX FIFO with the + * first TX bytes. Pre-filling the TX FIFO here to avoid the + * interrupt doesn't work:-( */ - if (cs & BCM2835_SPI_CS_DONE) { - if (bs->len) { /* First interrupt in a transfer */ - bcm2835_wr_fifo(bs, 16); - } else { /* Transfer complete */ - /* Disable SPI interrupts */ - cs &= ~(BCM2835_SPI_CS_INTR | BCM2835_SPI_CS_INTD); - bcm2835_wr(bs, BCM2835_SPI_CS, cs); - - /* - * Wake up bcm2835_spi_transfer_one(), which will call - * bcm2835_spi_finish_transfer(), to drain the RX FIFO. - */ - complete(&bs->done); - } - - return IRQ_HANDLED; - } + cs |= BCM2835_SPI_CS_INTR | BCM2835_SPI_CS_INTD | BCM2835_SPI_CS_TA; + bcm2835_wr(bs, BCM2835_SPI_CS, cs); - return IRQ_NONE; + /* signal that we need to wait for completion */ + return 1; } -static int bcm2835_spi_start_transfer(struct spi_device *spi, - struct spi_transfer *tfr) +static int bcm2835_spi_transfer_one(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *tfr) { - struct bcm2835_spi *bs = spi_master_get_devdata(spi->master); + struct bcm2835_spi *bs = spi_master_get_devdata(master); unsigned long spi_hz, clk_hz, cdiv; - u32 cs = BCM2835_SPI_CS_INTR | BCM2835_SPI_CS_INTD | BCM2835_SPI_CS_TA; + unsigned long spi_used_hz, xfer_time_us; + u32 cs = bcm2835_rd(bs, BCM2835_SPI_CS); + /* set clock */ spi_hz = tfr->speed_hz; clk_hz = clk_get_rate(bs->clk); if (spi_hz >= clk_hz / 2) { cdiv = 2; /* clk_hz/2 is the fastest we can go */ } else if (spi_hz) { - /* CDIV must be a power of two */ - cdiv = roundup_pow_of_two(DIV_ROUND_UP(clk_hz, spi_hz)); + /* CDIV must be a multiple of two */ + cdiv = DIV_ROUND_UP(clk_hz, spi_hz); + cdiv += (cdiv % 2); if (cdiv >= 65536) cdiv = 0; /* 0 is the slowest we can go */ - } else + } else { cdiv = 0; /* 0 is the slowest we can go */ + } + spi_used_hz = cdiv ? (clk_hz / cdiv) : (clk_hz / 65536); + bcm2835_wr(bs, BCM2835_SPI_CLK, cdiv); + /* handle all the modes */ + if ((spi->mode & SPI_3WIRE) && (tfr->rx_buf)) + cs |= BCM2835_SPI_CS_REN; if (spi->mode & SPI_CPOL) cs |= BCM2835_SPI_CS_CPOL; if (spi->mode & SPI_CPHA) cs |= BCM2835_SPI_CS_CPHA; - if (!(spi->mode & SPI_NO_CS)) { - if (spi->mode & SPI_CS_HIGH) { - cs |= BCM2835_SPI_CS_CSPOL; - cs |= BCM2835_SPI_CS_CSPOL0 << spi->chip_select; - } - - cs |= spi->chip_select; - } + /* for gpio_cs set dummy CS so that no HW-CS get changed + * we can not run this in bcm2835_spi_set_cs, as it does + * not get called for cs_gpio cases, so we need to do it here + */ + if (gpio_is_valid(spi->cs_gpio) || (spi->mode & SPI_NO_CS)) + cs |= BCM2835_SPI_CS_CS_10 | BCM2835_SPI_CS_CS_01; - reinit_completion(&bs->done); + /* set transmit buffers and length */ bs->tx_buf = tfr->tx_buf; bs->rx_buf = tfr->rx_buf; - bs->len = tfr->len; + bs->tx_len = tfr->len; + bs->rx_len = tfr->len; - bcm2835_wr(bs, BCM2835_SPI_CLK, cdiv); - /* - * Enable the HW block. This will immediately trigger a DONE (TX - * empty) interrupt, upon which we will fill the TX FIFO with the - * first TX bytes. Pre-filling the TX FIFO here to avoid the - * interrupt doesn't work:-( - */ - bcm2835_wr(bs, BCM2835_SPI_CS, cs); + /* calculate the estimated time in us the transfer runs */ + xfer_time_us = tfr->len + * 9 /* clocks/byte - SPI-HW waits 1 clock after each byte */ + * 1000000 / spi_used_hz; - return 0; + /* for short requests run polling*/ + if (xfer_time_us <= BCM2835_SPI_POLLING_LIMIT_US) + return bcm2835_spi_transfer_one_poll(master, spi, tfr, + cs, xfer_time_us); + + return bcm2835_spi_transfer_one_irq(master, spi, tfr, cs); } -static int bcm2835_spi_finish_transfer(struct spi_device *spi, - struct spi_transfer *tfr, bool cs_change) +static void bcm2835_spi_handle_err(struct spi_master *master, + struct spi_message *msg) { - struct bcm2835_spi *bs = spi_master_get_devdata(spi->master); - u32 cs = bcm2835_rd(bs, BCM2835_SPI_CS); + bcm2835_spi_reset_hw(master); +} + +static void bcm2835_spi_set_cs(struct spi_device *spi, bool gpio_level) +{ + /* + * we can assume that we are "native" as per spi_set_cs + * calling us ONLY when cs_gpio is not set + * we can also assume that we are CS < 3 as per bcm2835_spi_setup + * we would not get called because of error handling there. + * the level passed is the electrical level not enabled/disabled + * so it has to get translated back to enable/disable + * see spi_set_cs in spi.c for the implementation + */ - /* Drain RX FIFO */ - while (cs & BCM2835_SPI_CS_RXD) { - bcm2835_rd_fifo(bs, 1); - cs = bcm2835_rd(bs, BCM2835_SPI_CS); + struct spi_master *master = spi->master; + struct bcm2835_spi *bs = spi_master_get_devdata(master); + u32 cs = bcm2835_rd(bs, BCM2835_SPI_CS); + bool enable; + + /* calculate the enable flag from the passed gpio_level */ + enable = (spi->mode & SPI_CS_HIGH) ? gpio_level : !gpio_level; + + /* set flags for "reverse" polarity in the registers */ + if (spi->mode & SPI_CS_HIGH) { + /* set the correct CS-bits */ + cs |= BCM2835_SPI_CS_CSPOL; + cs |= BCM2835_SPI_CS_CSPOL0 << spi->chip_select; + } else { + /* clean the CS-bits */ + cs &= ~BCM2835_SPI_CS_CSPOL; + cs &= ~(BCM2835_SPI_CS_CSPOL0 << spi->chip_select); } - if (tfr->delay_usecs) - udelay(tfr->delay_usecs); + /* select the correct chip_select depending on disabled/enabled */ + if (enable) { + /* set cs correctly */ + if (spi->mode & SPI_NO_CS) { + /* use the "undefined" chip-select */ + cs |= BCM2835_SPI_CS_CS_10 | BCM2835_SPI_CS_CS_01; + } else { + /* set the chip select */ + cs &= ~(BCM2835_SPI_CS_CS_10 | BCM2835_SPI_CS_CS_01); + cs |= spi->chip_select; + } + } else { + /* disable CSPOL which puts HW-CS into deselected state */ + cs &= ~BCM2835_SPI_CS_CSPOL; + /* use the "undefined" chip-select as precaution */ + cs |= BCM2835_SPI_CS_CS_10 | BCM2835_SPI_CS_CS_01; + } - if (cs_change) - /* Clear TA flag */ - bcm2835_wr(bs, BCM2835_SPI_CS, cs & ~BCM2835_SPI_CS_TA); + /* finally set the calculated flags in SPI_CS */ + bcm2835_wr(bs, BCM2835_SPI_CS, cs); +} - return 0; +static int chip_match_name(struct gpio_chip *chip, void *data) +{ + return !strcmp(chip->label, data); } -static int bcm2835_spi_transfer_one(struct spi_master *master, - struct spi_message *mesg) +static int bcm2835_spi_setup(struct spi_device *spi) { - struct bcm2835_spi *bs = spi_master_get_devdata(master); - struct spi_transfer *tfr; - struct spi_device *spi = mesg->spi; - int err = 0; - unsigned int timeout; - bool cs_change; - - list_for_each_entry(tfr, &mesg->transfers, transfer_list) { - err = bcm2835_spi_start_transfer(spi, tfr); - if (err) - goto out; - - timeout = wait_for_completion_timeout(&bs->done, - msecs_to_jiffies(BCM2835_SPI_TIMEOUT_MS)); - if (!timeout) { - err = -ETIMEDOUT; - goto out; - } + int err; + struct gpio_chip *chip; + /* + * sanity checking the native-chipselects + */ + if (spi->mode & SPI_NO_CS) + return 0; + if (gpio_is_valid(spi->cs_gpio)) + return 0; + if (spi->chip_select > 1) { + /* error in the case of native CS requested with CS > 1 + * officially there is a CS2, but it is not documented + * which GPIO is connected with that... + */ + dev_err(&spi->dev, + "setup: only two native chip-selects are supported\n"); + return -EINVAL; + } + /* now translate native cs to GPIO */ - cs_change = tfr->cs_change || - list_is_last(&tfr->transfer_list, &mesg->transfers); + /* get the gpio chip for the base */ + chip = gpiochip_find("pinctrl-bcm2835", chip_match_name); + if (!chip) + return 0; - err = bcm2835_spi_finish_transfer(spi, tfr, cs_change); - if (err) - goto out; + /* and calculate the real CS */ + spi->cs_gpio = chip->base + 8 - spi->chip_select; - mesg->actual_length += (tfr->len - bs->len); - } + /* and set up the "mode" and level */ + dev_info(&spi->dev, "setting up native-CS%i as GPIO %i\n", + spi->chip_select, spi->cs_gpio); -out: - /* Clear FIFOs, and disable the HW block */ - bcm2835_wr(bs, BCM2835_SPI_CS, - BCM2835_SPI_CS_CLEAR_RX | BCM2835_SPI_CS_CLEAR_TX); - mesg->status = err; - spi_finalize_current_message(master); + /* set up GPIO as output and pull to the correct level */ + err = gpio_direction_output(spi->cs_gpio, + (spi->mode & SPI_CS_HIGH) ? 0 : 1); + if (err) { + dev_err(&spi->dev, + "could not set CS%i gpio %i as output: %i", + spi->chip_select, spi->cs_gpio, err); + return err; + } + /* the implementation of pinctrl-bcm2835 currently does not + * set the GPIO value when using gpio_direction_output + * so we are setting it here explicitly + */ + gpio_set_value(spi->cs_gpio, (spi->mode & SPI_CS_HIGH) ? 0 : 1); return 0; } @@ -312,13 +426,14 @@ static int bcm2835_spi_probe(struct platform_device *pdev) master->mode_bits = BCM2835_SPI_MODE_BITS; master->bits_per_word_mask = SPI_BPW_MASK(8); master->num_chipselect = 3; - master->transfer_one_message = bcm2835_spi_transfer_one; + master->setup = bcm2835_spi_setup; + master->set_cs = bcm2835_spi_set_cs; + master->transfer_one = bcm2835_spi_transfer_one; + master->handle_err = bcm2835_spi_handle_err; master->dev.of_node = pdev->dev.of_node; bs = spi_master_get_devdata(master); - init_completion(&bs->done); - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); bs->regs = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(bs->regs)) { @@ -343,13 +458,13 @@ static int bcm2835_spi_probe(struct platform_device *pdev) clk_prepare_enable(bs->clk); err = devm_request_irq(&pdev->dev, bs->irq, bcm2835_spi_interrupt, 0, - dev_name(&pdev->dev), master); + dev_name(&pdev->dev), master); if (err) { dev_err(&pdev->dev, "could not request IRQ: %d\n", err); goto out_clk_disable; } - /* initialise the hardware */ + /* initialise the hardware with the default polarities */ bcm2835_wr(bs, BCM2835_SPI_CS, BCM2835_SPI_CS_CLEAR_RX | BCM2835_SPI_CS_CLEAR_TX); diff --git a/drivers/spi/spi-bcm53xx.c b/drivers/spi/spi-bcm53xx.c index 3fb91c81015a..1520554978a3 100644 --- a/drivers/spi/spi-bcm53xx.c +++ b/drivers/spi/spi-bcm53xx.c @@ -44,7 +44,7 @@ static int bcm53xxspi_wait(struct bcm53xxspi *b53spi, unsigned int timeout_ms) u32 tmp; /* SPE bit has to be 0 before we read MSPI STATUS */ - deadline = jiffies + BCM53XXSPI_SPE_TIMEOUT_MS * HZ / 1000; + deadline = jiffies + msecs_to_jiffies(BCM53XXSPI_SPE_TIMEOUT_MS); do { tmp = bcm53xxspi_read(b53spi, B53SPI_MSPI_SPCR2); if (!(tmp & B53SPI_MSPI_SPCR2_SPE)) @@ -56,7 +56,7 @@ static int bcm53xxspi_wait(struct bcm53xxspi *b53spi, unsigned int timeout_ms) goto spi_timeout; /* Check status */ - deadline = jiffies + timeout_ms * HZ / 1000; + deadline = jiffies + msecs_to_jiffies(timeout_ms); do { tmp = bcm53xxspi_read(b53spi, B53SPI_MSPI_MSPI_STATUS); if (tmp & B53SPI_MSPI_MSPI_STATUS_SPIF) { diff --git a/drivers/spi/spi-bitbang-txrx.h b/drivers/spi/spi-bitbang-txrx.h index c616e41521be..06b34e5bcfa3 100644 --- a/drivers/spi/spi-bitbang-txrx.h +++ b/drivers/spi/spi-bitbang-txrx.h @@ -49,12 +49,17 @@ bitbang_txrx_be_cpha0(struct spi_device *spi, { /* if (cpol == 0) this is SPI_MODE_0; else this is SPI_MODE_2 */ + bool oldbit = !(word & 1); /* clock starts at inactive polarity */ for (word <<= (32 - bits); likely(bits); bits--) { /* setup MSB (to slave) on trailing edge */ - if ((flags & SPI_MASTER_NO_TX) == 0) - setmosi(spi, word & (1 << 31)); + if ((flags & SPI_MASTER_NO_TX) == 0) { + if ((word & (1 << 31)) != oldbit) { + setmosi(spi, word & (1 << 31)); + oldbit = word & (1 << 31); + } + } spidelay(nsecs); /* T(setup) */ setsck(spi, !cpol); @@ -76,13 +81,18 @@ bitbang_txrx_be_cpha1(struct spi_device *spi, { /* if (cpol == 0) this is SPI_MODE_1; else this is SPI_MODE_3 */ + bool oldbit = !(word & (1 << 31)); /* clock starts at inactive polarity */ for (word <<= (32 - bits); likely(bits); bits--) { /* setup MSB (to slave) on leading edge */ setsck(spi, !cpol); - if ((flags & SPI_MASTER_NO_TX) == 0) - setmosi(spi, word & (1 << 31)); + if ((flags & SPI_MASTER_NO_TX) == 0) { + if ((word & (1 << 31)) != oldbit) { + setmosi(spi, word & (1 << 31)); + oldbit = word & (1 << 31); + } + } spidelay(nsecs); /* T(setup) */ setsck(spi, cpol); diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 5223bd0ed360..865786012579 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -850,6 +850,9 @@ out: if (msg->status == -EINPROGRESS) msg->status = ret; + if (msg->status) + master->handle_err(master, msg); + spi_finalize_current_message(master); return ret; diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 856d34dde79b..71e9d880f86e 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -294,6 +294,8 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) * transfer_one_message are mutually exclusive; when both * are set, the generic subsystem does not call your * transfer_one callback. + * @handle_err: the subsystem calls the driver to handle and error that occurs + * in the generic implementation of transfer_one_message(). * @unprepare_message: undo any work done by prepare_message(). * @cs_gpios: Array of GPIOs to use as chip select lines; one per CS * number. Any individual value may be -ENOENT for CS lines that @@ -448,6 +450,8 @@ struct spi_master { void (*set_cs)(struct spi_device *spi, bool enable); int (*transfer_one)(struct spi_master *master, struct spi_device *spi, struct spi_transfer *transfer); + void (*handle_err)(struct spi_master *master, + struct spi_message *message); /* gpio chip select */ int *cs_gpios; |