diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index e358ac5b4509777e0827630e2f6e58c385f9a54c..96a524772549ee8d9a4b9f936dd83b52f87c4169 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c
@@ -164,16 +164,20 @@ static void spi_engine_gen_xfer(struct spi_engine_program *p, bool dry,
}
static void spi_engine_gen_sleep(struct spi_engine_program *p, bool dry,
- int delay_ns, u32 sclk_hz)
+ int delay_ns, int inst_ns, u32 sclk_hz)
{
unsigned int t;
- /* negative delay indicates error, e.g. from spi_delay_to_ns() */
- if (delay_ns <= 0)
+ /*
+ * Negative delay indicates error, e.g. from spi_delay_to_ns(). And if
+ * delay is less that the instruction execution time, there is no need
+ * for an extra sleep instruction since the instruction execution time
+ * will already cover the required delay.
+ */
+ if (delay_ns < 0 || delay_ns <= inst_ns)
return;
- /* rounding down since executing the instruction adds a couple of ticks delay */
- t = DIV_ROUND_DOWN_ULL((u64)delay_ns * sclk_hz, NSEC_PER_SEC);
+ t = DIV_ROUND_UP_ULL((u64)(delay_ns - inst_ns) * sclk_hz, NSEC_PER_SEC);
while (t) {
unsigned int n = min(t, 256U);
@@ -220,10 +224,16 @@ static void spi_engine_compile_message(struct spi_message *msg, bool dry,
struct spi_device *spi = msg->spi;
struct spi_controller *host = spi->controller;
struct spi_transfer *xfer;
- int clk_div, new_clk_div;
+ int clk_div, new_clk_div, inst_ns;
bool keep_cs = false;
u8 bits_per_word = 0;
+ /*
+ * Take into account instruction execution time for more accurate sleep
+ * times, especially when the delay is small.
+ */
+ inst_ns = DIV_ROUND_UP(NSEC_PER_SEC, host->max_speed_hz);
+
clk_div = 1;
spi_engine_program_add_cmd(p, dry,
@@ -252,7 +262,7 @@ static void spi_engine_compile_message(struct spi_message *msg, bool dry,
spi_engine_gen_xfer(p, dry, xfer);
spi_engine_gen_sleep(p, dry, spi_delay_to_ns(&xfer->delay, xfer),
- xfer->effective_speed_hz);
+ inst_ns, xfer->effective_speed_hz);
if (xfer->cs_change) {
if (list_is_last(&xfer->transfer_list, &msg->transfers)) {
@@ -262,7 +272,7 @@ static void spi_engine_compile_message(struct spi_message *msg, bool dry,
spi_engine_gen_cs(p, dry, spi, false);
spi_engine_gen_sleep(p, dry, spi_delay_to_ns(
- &xfer->cs_change_delay, xfer),
+ &xfer->cs_change_delay, xfer), inst_ns,
xfer->effective_speed_hz);
if (!list_next_entry(xfer, transfer_list)->cs_off)
diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c
index be3998104bfbb32363d7c575c61bc6ff7013bebb..f7e8b5efa50e56978cb852a709c4649985b2a3b7 100644
--- a/drivers/spi/spi-davinci.c
+++ b/drivers/spi/spi-davinci.c
@@ -984,6 +984,9 @@ static int davinci_spi_probe(struct platform_device *pdev)
return ret;
free_dma:
+ /* This bit needs to be cleared to disable dpsi->clk */
+ clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK);
+
if (dspi->dma_rx) {
dma_release_channel(dspi->dma_rx);
dma_release_channel(dspi->dma_tx);
@@ -1013,6 +1016,9 @@ static void davinci_spi_remove(struct platform_device *pdev)
spi_bitbang_stop(&dspi->bitbang);
+ /* This bit needs to be cleared to disable dpsi->clk */
+ clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK);
+
if (dspi->dma_rx) {
dma_release_channel(dspi->dma_rx);
dma_release_channel(dspi->dma_tx);
diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 33164ebdb583118f70f84f3d8dd1bfd4914d2187..1439883326cfe11a2db96a10a86bfffb234bb1c1 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -1050,7 +1050,7 @@ static struct spi_imx_devtype_data imx35_cspi_devtype_data = {
.rx_available = mx31_rx_available,
.reset = mx31_reset,
.fifo_size = 8,
- .has_dmamode = true,
+ .has_dmamode = false,
.dynamic_burst = false,
.has_targetmode = false,
.devtype = IMX35_CSPI,
diff --git a/drivers/spi/spi-mux.c b/drivers/spi/spi-mux.c
index 5d72e3d59df837c536c4b7bde682d906a331cf49..c02c4204442f5eb614a4231fa193e5efb887dd75 100644
--- a/drivers/spi/spi-mux.c
+++ b/drivers/spi/spi-mux.c
@@ -158,12 +158,14 @@ static int spi_mux_probe(struct spi_device *spi)
/* supported modes are the same as our parent's */
ctlr->mode_bits = spi->controller->mode_bits;
ctlr->flags = spi->controller->flags;
+ ctlr->bits_per_word_mask = spi->controller->bits_per_word_mask;
ctlr->transfer_one_message = spi_mux_transfer_one_message;
ctlr->setup = spi_mux_setup;
ctlr->num_chipselect = mux_control_states(priv->mux);
ctlr->bus_num = -1;
ctlr->dev.of_node = spi->dev.of_node;
ctlr->must_async = true;
+ ctlr->defer_optimize_message = true;
ret = devm_spi_register_controller(&spi->dev, ctlr);
if (ret)
diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index 7e3083b835348af45b49317f9bac53b39169caa3..002f29dbcea6e72ce6224f3f89f32fca46c43542 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -1277,24 +1277,11 @@ static int omap2_mcspi_prepare_message(struct spi_controller *ctlr,
/*
* Check if this transfer contains only one word;
- * OR contains 1 to 4 words, with bits_per_word == 8 and no delay between each word
- * OR contains 1 to 2 words, with bits_per_word == 16 and no delay between each word
- *
- * If one of the two last case is true, this also change the bits_per_word of this
- * transfer to make it a bit faster.
- * It's not an issue to change the bits_per_word here even if the multi-mode is not
- * applicable for this message, the signal on the wire will be the same.
*/
if (bits_per_word < 8 && tr->len == 1) {
/* multi-mode is applicable, only one word (1..7 bits) */
- } else if (tr->word_delay.value == 0 && bits_per_word == 8 && tr->len <= 4) {
- /* multi-mode is applicable, only one "bigger" word (8,16,24,32 bits) */
- tr->bits_per_word = tr->len * bits_per_word;
- } else if (tr->word_delay.value == 0 && bits_per_word == 16 && tr->len <= 2) {
- /* multi-mode is applicable, only one "bigger" word (16,32 bits) */
- tr->bits_per_word = tr->len * bits_per_word / 2;
} else if (bits_per_word >= 8 && tr->len == bits_per_word / 8) {
- /* multi-mode is applicable, only one word (9..15,17..32 bits) */
+ /* multi-mode is applicable, only one word (8..32 bits) */
} else {
/* multi-mode is not applicable: more than one word in the transfer */
mcspi->use_multi_mode = false;
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index fc13fa19218955823caa883f5cef23ad62ef3a23..0f04e832f9ec2349a1dc074dbeb25706a908d553 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -2151,7 +2151,8 @@ static void __spi_unoptimize_message(struct spi_message *msg)
*/
static void spi_maybe_unoptimize_message(struct spi_message *msg)
{
- if (!msg->pre_optimized && msg->optimized)
+ if (!msg->pre_optimized && msg->optimized &&
+ !msg->spi->controller->defer_optimize_message)
__spi_unoptimize_message(msg);
}
@@ -4294,6 +4295,11 @@ static int __spi_optimize_message(struct spi_device *spi,
static int spi_maybe_optimize_message(struct spi_device *spi,
struct spi_message *msg)
{
+ if (spi->controller->defer_optimize_message) {
+ msg->spi = spi;
+ return 0;
+ }
+
if (msg->pre_optimized)
return 0;
@@ -4324,6 +4330,13 @@ int spi_optimize_message(struct spi_device *spi, struct spi_message *msg)
{
int ret;
+ /*
+ * Pre-optimization is not supported and optimization is deferred e.g.
+ * when using spi-mux.
+ */
+ if (spi->controller->defer_optimize_message)
+ return 0;
+
ret = __spi_optimize_message(spi, msg);
if (ret)
return ret;
@@ -4350,6 +4363,9 @@ EXPORT_SYMBOL_GPL(spi_optimize_message);
*/
void spi_unoptimize_message(struct spi_message *msg)
{
+ if (msg->spi->controller->defer_optimize_message)
+ return;
+
__spi_unoptimize_message(msg);
msg->pre_optimized = false;
}
@@ -4432,8 +4448,6 @@ int spi_async(struct spi_device *spi, struct spi_message *message)
spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
- spi_maybe_unoptimize_message(message);
-
return ret;
}
EXPORT_SYMBOL_GPL(spi_async);
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 98fdef6e28f2a79bae853710ffa978e13414f440..67b9a15a5330f8767451913f36d51a52e082bbbb 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -533,6 +533,9 @@ extern struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 ch
* @queue_empty: signal green light for opportunistically skipping the queue
* for spi_sync transfers.
* @must_async: disable all fast paths in the core
+ * @defer_optimize_message: set to true if controller cannot pre-optimize messages
+ * and needs to defer the optimization step until the message is actually
+ * being transferred
*
* Each SPI controller can communicate with one or more @spi_device
* children. These make a small bus, sharing MOSI, MISO and SCK signals
@@ -776,6 +779,7 @@ struct spi_controller {
/* Flag for enabling opportunistic skipping of the queue in spi_sync */
bool queue_empty;
bool must_async;
+ bool defer_optimize_message;
};
static inline void *spi_controller_get_devdata(struct spi_controller *ctlr)