Merge tag 'drivers-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc

[linux-2.6-microblaze.git] / drivers / spi / spi-imx.c

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 63a8d7b..b2dd0a4 100644 (file)
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -510,7 +510,9 @@ static int mx51_ecspi_prepare_message(struct spi_imx_data *spi_imx,
                                      struct spi_message *msg)
 {
        struct spi_device *spi = msg->spi;
+       struct spi_transfer *xfer;
        u32 ctrl = MX51_ECSPI_CTRL_ENABLE;
+       u32 min_speed_hz = ~0U;
        u32 testreg, delay;
        u32 cfg = readl(spi_imx->base + MX51_ECSPI_CONFIG);
 
@@ -582,9 +584,21 @@ static int mx51_ecspi_prepare_message(struct spi_imx_data *spi_imx,
         * be asserted before the SCLK polarity changes, which would disrupt
         * the SPI communication as the device on the other end would consider
         * the change of SCLK polarity as a clock tick already.
+        *
+        * Because spi_imx->spi_bus_clk is only set in bitbang prepare_message
+        * callback, iterate over all the transfers in spi_message, find the
+        * one with lowest bus frequency, and use that bus frequency for the
+        * delay calculation. In case all transfers have speed_hz == 0, then
+        * min_speed_hz is ~0 and the resulting delay is zero.
         */
-       delay = (2 * 1000000) / spi_imx->spi_bus_clk;
-       if (likely(delay < 10)) /* SCLK is faster than 100 kHz */
+       list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+               if (!xfer->speed_hz)
+                       continue;
+               min_speed_hz = min(xfer->speed_hz, min_speed_hz);
+       }
+
+       delay = (2 * 1000000) / min_speed_hz;
+       if (likely(delay < 10)) /* SCLK is faster than 200 kHz */
                udelay(delay);
        else                    /* SCLK is _very_ slow */
                usleep_range(delay, delay + 10);
@@ -1071,12 +1085,8 @@ static void spi_imx_set_burst_len(struct spi_imx_data *spi_imx, int n_bits)
 
 static void spi_imx_push(struct spi_imx_data *spi_imx)
 {
-       unsigned int burst_len, fifo_words;
+       unsigned int burst_len;
 
-       if (spi_imx->dynamic_burst)
-               fifo_words = 4;
-       else
-               fifo_words = spi_imx_bytes_per_word(spi_imx->bits_per_word);
        /*
         * Reload the FIFO when the remaining bytes to be transferred in the
         * current burst is 0. This only applies when bits_per_word is a
@@ -1095,7 +1105,7 @@ static void spi_imx_push(struct spi_imx_data *spi_imx)
 
                        spi_imx->remainder = burst_len;
                } else {
-                       spi_imx->remainder = fifo_words;
+                       spi_imx->remainder = spi_imx_bytes_per_word(spi_imx->bits_per_word);
                }
        }
 
@@ -1103,8 +1113,7 @@ static void spi_imx_push(struct spi_imx_data *spi_imx)
                if (!spi_imx->count)
                        break;
                if (spi_imx->dynamic_burst &&
-                   spi_imx->txfifo >= DIV_ROUND_UP(spi_imx->remainder,
-                                                    fifo_words))
+                   spi_imx->txfifo >= DIV_ROUND_UP(spi_imx->remainder, 4))
                        break;
                spi_imx->tx(spi_imx);
                spi_imx->txfifo++;
@@ -1214,6 +1223,7 @@ static int spi_imx_setupxfer(struct spi_device *spi,
         * dynamic_burst in that case.
         */
        if (spi_imx->devtype_data->dynamic_burst && !spi_imx->slave_mode &&
+           !(spi->mode & SPI_CS_WORD) &&
            (spi_imx->bits_per_word == 8 ||
            spi_imx->bits_per_word == 16 ||
            spi_imx->bits_per_word == 32)) {
@@ -1645,6 +1655,15 @@ static int spi_imx_probe(struct platform_device *pdev)
            is_imx53_ecspi(spi_imx))
                spi_imx->bitbang.master->mode_bits |= SPI_LOOP | SPI_READY;
 
+       if (is_imx51_ecspi(spi_imx) &&
+           device_property_read_u32(&pdev->dev, "cs-gpios", NULL))
+               /*
+                * When using HW-CS implementing SPI_CS_WORD can be done by just
+                * setting the burst length to the word size. This is
+                * considerably faster than manually controlling the CS.
+                */
+               spi_imx->bitbang.master->mode_bits |= SPI_CS_WORD;
+
        spi_imx->spi_drctl = spi_drctl;
 
        init_completion(&spi_imx->xfer_done);