diff options
Diffstat (limited to 'kernel/drivers/spi/spi-omap2-mcspi.c')
-rw-r--r-- | kernel/drivers/spi/spi-omap2-mcspi.c | 317 |
1 files changed, 172 insertions, 145 deletions
diff --git a/kernel/drivers/spi/spi-omap2-mcspi.c b/kernel/drivers/spi/spi-omap2-mcspi.c index d1a5b9fc3..ed8283e73 100644 --- a/kernel/drivers/spi/spi-omap2-mcspi.c +++ b/kernel/drivers/spi/spi-omap2-mcspi.c @@ -35,6 +35,7 @@ #include <linux/gcd.h> #include <linux/spi/spi.h> +#include <linux/gpio.h> #include <linux/platform_data/spi-omap2-mcspi.h> @@ -242,17 +243,37 @@ static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable) mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0); } -static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active) +static void omap2_mcspi_set_cs(struct spi_device *spi, bool enable) { + struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master); u32 l; - l = mcspi_cached_chconf0(spi); - if (cs_active) - l |= OMAP2_MCSPI_CHCONF_FORCE; - else - l &= ~OMAP2_MCSPI_CHCONF_FORCE; + /* The controller handles the inverted chip selects + * using the OMAP2_MCSPI_CHCONF_EPOL bit so revert + * the inversion from the core spi_set_cs function. + */ + if (spi->mode & SPI_CS_HIGH) + enable = !enable; - mcspi_write_chconf0(spi, l); + if (spi->controller_state) { + int err = pm_runtime_get_sync(mcspi->dev); + if (err < 0) { + dev_err(mcspi->dev, "failed to get sync: %d\n", err); + return; + } + + l = mcspi_cached_chconf0(spi); + + if (enable) + l &= ~OMAP2_MCSPI_CHCONF_FORCE; + else + l |= OMAP2_MCSPI_CHCONF_FORCE; + + mcspi_write_chconf0(spi, l); + + pm_runtime_mark_last_busy(mcspi->dev); + pm_runtime_put_autosuspend(mcspi->dev); + } } static void omap2_mcspi_set_master_mode(struct spi_master *master) @@ -1003,6 +1024,16 @@ static int omap2_mcspi_setup(struct spi_device *spi) spi->controller_state = cs; /* Link this to context save list */ list_add_tail(&cs->node, &ctx->cs); + + if (gpio_is_valid(spi->cs_gpio)) { + ret = gpio_request(spi->cs_gpio, dev_name(&spi->dev)); + if (ret) { + dev_err(&spi->dev, "failed to request gpio\n"); + return ret; + } + gpio_direction_output(spi->cs_gpio, + !(spi->mode & SPI_CS_HIGH)); + } } if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx) { @@ -1050,9 +1081,13 @@ static void omap2_mcspi_cleanup(struct spi_device *spi) mcspi_dma->dma_tx = NULL; } } + + if (gpio_is_valid(spi->cs_gpio)) + gpio_free(spi->cs_gpio); } -static void omap2_mcspi_work(struct omap2_mcspi *mcspi, struct spi_message *m) +static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi, + struct spi_device *spi, struct spi_transfer *t) { /* We only enable one channel at a time -- the one whose message is @@ -1062,18 +1097,14 @@ static void omap2_mcspi_work(struct omap2_mcspi *mcspi, struct spi_message *m) * chipselect with the FORCE bit ... CS != channel enable. */ - struct spi_device *spi; - struct spi_transfer *t = NULL; struct spi_master *master; struct omap2_mcspi_dma *mcspi_dma; - int cs_active = 0; struct omap2_mcspi_cs *cs; struct omap2_mcspi_device_config *cd; int par_override = 0; int status = 0; u32 chconf; - spi = m->spi; master = spi->master; mcspi_dma = mcspi->dma_channels + spi->chip_select; cs = spi->controller_state; @@ -1090,103 +1121,84 @@ static void omap2_mcspi_work(struct omap2_mcspi *mcspi, struct spi_message *m) par_override = 1; omap2_mcspi_set_enable(spi, 0); - list_for_each_entry(t, &m->transfers, transfer_list) { - if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) { - status = -EINVAL; - break; - } - if (par_override || - (t->speed_hz != spi->max_speed_hz) || - (t->bits_per_word != spi->bits_per_word)) { - par_override = 1; - status = omap2_mcspi_setup_transfer(spi, t); - if (status < 0) - break; - if (t->speed_hz == spi->max_speed_hz && - t->bits_per_word == spi->bits_per_word) - par_override = 0; - } - if (cd && cd->cs_per_word) { - chconf = mcspi->ctx.modulctrl; - chconf &= ~OMAP2_MCSPI_MODULCTRL_SINGLE; - mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf); - mcspi->ctx.modulctrl = - mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL); - } + if (gpio_is_valid(spi->cs_gpio)) + omap2_mcspi_set_cs(spi, spi->mode & SPI_CS_HIGH); - if (!cs_active) { - omap2_mcspi_force_cs(spi, 1); - cs_active = 1; - } - - chconf = mcspi_cached_chconf0(spi); - chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK; - chconf &= ~OMAP2_MCSPI_CHCONF_TURBO; + if (par_override || + (t->speed_hz != spi->max_speed_hz) || + (t->bits_per_word != spi->bits_per_word)) { + par_override = 1; + status = omap2_mcspi_setup_transfer(spi, t); + if (status < 0) + goto out; + if (t->speed_hz == spi->max_speed_hz && + t->bits_per_word == spi->bits_per_word) + par_override = 0; + } + if (cd && cd->cs_per_word) { + chconf = mcspi->ctx.modulctrl; + chconf &= ~OMAP2_MCSPI_MODULCTRL_SINGLE; + mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf); + mcspi->ctx.modulctrl = + mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL); + } - if (t->tx_buf == NULL) - chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY; - else if (t->rx_buf == NULL) - chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY; - - if (cd && cd->turbo_mode && t->tx_buf == NULL) { - /* Turbo mode is for more than one word */ - if (t->len > ((cs->word_len + 7) >> 3)) - chconf |= OMAP2_MCSPI_CHCONF_TURBO; - } + chconf = mcspi_cached_chconf0(spi); + chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK; + chconf &= ~OMAP2_MCSPI_CHCONF_TURBO; + + if (t->tx_buf == NULL) + chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY; + else if (t->rx_buf == NULL) + chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY; + + if (cd && cd->turbo_mode && t->tx_buf == NULL) { + /* Turbo mode is for more than one word */ + if (t->len > ((cs->word_len + 7) >> 3)) + chconf |= OMAP2_MCSPI_CHCONF_TURBO; + } - mcspi_write_chconf0(spi, chconf); + mcspi_write_chconf0(spi, chconf); - if (t->len) { - unsigned count; + if (t->len) { + unsigned count; - if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) && - (m->is_dma_mapped || t->len >= DMA_MIN_BYTES)) - omap2_mcspi_set_fifo(spi, t, 1); + if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) && + (t->len >= DMA_MIN_BYTES)) + omap2_mcspi_set_fifo(spi, t, 1); - omap2_mcspi_set_enable(spi, 1); + omap2_mcspi_set_enable(spi, 1); - /* RX_ONLY mode needs dummy data in TX reg */ - if (t->tx_buf == NULL) - writel_relaxed(0, cs->base - + OMAP2_MCSPI_TX0); + /* RX_ONLY mode needs dummy data in TX reg */ + if (t->tx_buf == NULL) + writel_relaxed(0, cs->base + + OMAP2_MCSPI_TX0); - if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) && - (m->is_dma_mapped || t->len >= DMA_MIN_BYTES)) - count = omap2_mcspi_txrx_dma(spi, t); - else - count = omap2_mcspi_txrx_pio(spi, t); - m->actual_length += count; + if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) && + (t->len >= DMA_MIN_BYTES)) + count = omap2_mcspi_txrx_dma(spi, t); + else + count = omap2_mcspi_txrx_pio(spi, t); - if (count != t->len) { - status = -EIO; - break; - } + if (count != t->len) { + status = -EIO; + goto out; } + } - if (t->delay_usecs) - udelay(t->delay_usecs); - - /* ignore the "leave it on after last xfer" hint */ - if (t->cs_change) { - omap2_mcspi_force_cs(spi, 0); - cs_active = 0; - } + omap2_mcspi_set_enable(spi, 0); - omap2_mcspi_set_enable(spi, 0); + if (mcspi->fifo_depth > 0) + omap2_mcspi_set_fifo(spi, t, 0); - if (mcspi->fifo_depth > 0) - omap2_mcspi_set_fifo(spi, t, 0); - } +out: /* Restore defaults if they were overriden */ if (par_override) { par_override = 0; status = omap2_mcspi_setup_transfer(spi, NULL); } - if (cs_active) - omap2_mcspi_force_cs(spi, 0); - if (cd && cd->cs_per_word) { chconf = mcspi->ctx.modulctrl; chconf |= OMAP2_MCSPI_MODULCTRL_SINGLE; @@ -1197,78 +1209,91 @@ static void omap2_mcspi_work(struct omap2_mcspi *mcspi, struct spi_message *m) omap2_mcspi_set_enable(spi, 0); + if (gpio_is_valid(spi->cs_gpio)) + omap2_mcspi_set_cs(spi, !(spi->mode & SPI_CS_HIGH)); + if (mcspi->fifo_depth > 0 && t) omap2_mcspi_set_fifo(spi, t, 0); - m->status = status; + return status; } -static int omap2_mcspi_transfer_one_message(struct spi_master *master, - struct spi_message *m) +static int omap2_mcspi_prepare_message(struct spi_master *master, + struct spi_message *msg) +{ + struct omap2_mcspi *mcspi = spi_master_get_devdata(master); + struct omap2_mcspi_regs *ctx = &mcspi->ctx; + struct omap2_mcspi_cs *cs; + + /* Only a single channel can have the FORCE bit enabled + * in its chconf0 register. + * Scan all channels and disable them except the current one. + * A FORCE can remain from a last transfer having cs_change enabled + */ + list_for_each_entry(cs, &ctx->cs, node) { + if (msg->spi->controller_state == cs) + continue; + + if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE)) { + cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE; + writel_relaxed(cs->chconf0, + cs->base + OMAP2_MCSPI_CHCONF0); + readl_relaxed(cs->base + OMAP2_MCSPI_CHCONF0); + } + } + + return 0; +} + +static int omap2_mcspi_transfer_one(struct spi_master *master, + struct spi_device *spi, struct spi_transfer *t) { - struct spi_device *spi; struct omap2_mcspi *mcspi; struct omap2_mcspi_dma *mcspi_dma; - struct spi_transfer *t; - int status; + const void *tx_buf = t->tx_buf; + void *rx_buf = t->rx_buf; + unsigned len = t->len; - spi = m->spi; mcspi = spi_master_get_devdata(master); mcspi_dma = mcspi->dma_channels + spi->chip_select; - m->actual_length = 0; - m->status = 0; - - list_for_each_entry(t, &m->transfers, transfer_list) { - const void *tx_buf = t->tx_buf; - void *rx_buf = t->rx_buf; - unsigned len = t->len; - - if ((len && !(rx_buf || tx_buf))) { - dev_dbg(mcspi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n", - t->speed_hz, - len, - tx_buf ? "tx" : "", - rx_buf ? "rx" : "", - t->bits_per_word); - status = -EINVAL; - goto out; - } - if (m->is_dma_mapped || len < DMA_MIN_BYTES) - continue; + if ((len && !(rx_buf || tx_buf))) { + dev_dbg(mcspi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n", + t->speed_hz, + len, + tx_buf ? "tx" : "", + rx_buf ? "rx" : "", + t->bits_per_word); + return -EINVAL; + } - if (mcspi_dma->dma_tx && tx_buf != NULL) { - t->tx_dma = dma_map_single(mcspi->dev, (void *) tx_buf, - len, DMA_TO_DEVICE); - if (dma_mapping_error(mcspi->dev, t->tx_dma)) { - dev_dbg(mcspi->dev, "dma %cX %d bytes error\n", - 'T', len); - status = -EINVAL; - goto out; - } + if (len < DMA_MIN_BYTES) + goto skip_dma_map; + + if (mcspi_dma->dma_tx && tx_buf != NULL) { + t->tx_dma = dma_map_single(mcspi->dev, (void *) tx_buf, + len, DMA_TO_DEVICE); + if (dma_mapping_error(mcspi->dev, t->tx_dma)) { + dev_dbg(mcspi->dev, "dma %cX %d bytes error\n", + 'T', len); + return -EINVAL; } - if (mcspi_dma->dma_rx && rx_buf != NULL) { - t->rx_dma = dma_map_single(mcspi->dev, rx_buf, t->len, - DMA_FROM_DEVICE); - if (dma_mapping_error(mcspi->dev, t->rx_dma)) { - dev_dbg(mcspi->dev, "dma %cX %d bytes error\n", - 'R', len); - if (tx_buf != NULL) - dma_unmap_single(mcspi->dev, t->tx_dma, - len, DMA_TO_DEVICE); - status = -EINVAL; - goto out; - } + } + if (mcspi_dma->dma_rx && rx_buf != NULL) { + t->rx_dma = dma_map_single(mcspi->dev, rx_buf, t->len, + DMA_FROM_DEVICE); + if (dma_mapping_error(mcspi->dev, t->rx_dma)) { + dev_dbg(mcspi->dev, "dma %cX %d bytes error\n", + 'R', len); + if (tx_buf != NULL) + dma_unmap_single(mcspi->dev, t->tx_dma, + len, DMA_TO_DEVICE); + return -EINVAL; } } - omap2_mcspi_work(mcspi, m); - /* spi_finalize_current_message() changes the status inside the - * spi_message, save the status here. */ - status = m->status; -out: - spi_finalize_current_message(master); - return status; +skip_dma_map: + return omap2_mcspi_work_one(mcspi, spi, t); } static int omap2_mcspi_master_setup(struct omap2_mcspi *mcspi) @@ -1347,7 +1372,9 @@ static int omap2_mcspi_probe(struct platform_device *pdev) master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32); master->setup = omap2_mcspi_setup; master->auto_runtime_pm = true; - master->transfer_one_message = omap2_mcspi_transfer_one_message; + master->prepare_message = omap2_mcspi_prepare_message; + master->transfer_one = omap2_mcspi_transfer_one; + master->set_cs = omap2_mcspi_set_cs; master->cleanup = omap2_mcspi_cleanup; master->dev.of_node = node; master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ; |