Merge remote-tracking branch 'spi/topic/tegra114' into spi-next

1 files changed, 68 insertions, 17 deletions

diff --git a/drivers/spi/spi-tegra114.c b/drivers/spi/spi-tegra114.c
index b3821fb9da3f..9146bb3c2489 100644
--- a/drivers/spi/spi-tegra114.c
+++ b/drivers/spi/spi-tegra114.c
@@ -182,6 +182,7 @@ struct tegra_spi_data {
         u32                                     cur_speed;
 
         struct spi_device                       *cur_spi;
+        struct spi_device                       *cs_control;
         unsigned                                cur_pos;
         unsigned                                cur_len;
         unsigned                                words_per_32bit;
@@ -676,15 +677,12 @@ static void tegra_spi_deinit_dma_param(struct tegra_spi_data *tspi,
         dma_release_channel(dma_chan);
 }
 
-static int tegra_spi_start_transfer_one(struct spi_device *spi,
-                struct spi_transfer *t, bool is_first_of_msg,
-                bool is_single_xfer)
+static unsigned long tegra_spi_setup_transfer_one(struct spi_device *spi,
+                struct spi_transfer *t, bool is_first_of_msg)
 {
         struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
         u32 speed = t->speed_hz;
         u8 bits_per_word = t->bits_per_word;
-        unsigned total_fifo_words;
-        int ret;
         unsigned long command1;
         int req_mode;
 
@@ -698,7 +696,6 @@ static int tegra_spi_start_transfer_one(struct spi_device *spi,
         tspi->cur_rx_pos = 0;
         tspi->cur_tx_pos = 0;
         tspi->curr_xfer = t;
-        total_fifo_words = tegra_spi_calculate_curr_xfer_param(spi, tspi, t);
 
         if (is_first_of_msg) {
                 tegra_spi_clear_status(tspi);
@@ -717,7 +714,12 @@ static int tegra_spi_start_transfer_one(struct spi_device *spi,
                 else if (req_mode == SPI_MODE_3)
                         command1 |= SPI_CONTROL_MODE_3;
 
-                tegra_spi_writel(tspi, command1, SPI_COMMAND1);
+                if (tspi->cs_control) {
+                        if (tspi->cs_control != spi)
+                                tegra_spi_writel(tspi, command1, SPI_COMMAND1);
+                        tspi->cs_control = NULL;
+                } else
+                        tegra_spi_writel(tspi, command1, SPI_COMMAND1);
 
                 command1 |= SPI_CS_SW_HW;
                 if (spi->mode & SPI_CS_HIGH)
@@ -732,6 +734,18 @@ static int tegra_spi_start_transfer_one(struct spi_device *spi,
                 command1 |= SPI_BIT_LENGTH(bits_per_word - 1);
         }
 
+        return command1;
+}
+
+static int tegra_spi_start_transfer_one(struct spi_device *spi,
+                struct spi_transfer *t, unsigned long command1)
+{
+        struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
+        unsigned total_fifo_words;
+        int ret;
+
+        total_fifo_words = tegra_spi_calculate_curr_xfer_param(spi, tspi, t);
+
         if (tspi->is_packed)
                 command1 |= SPI_PACKED;
 
@@ -803,29 +817,50 @@ static int tegra_spi_setup(struct spi_device *spi)
         return 0;
 }
 
+static void tegra_spi_transfer_delay(int delay)
+{
+        if (!delay)
+                return;
+
+        if (delay >= 1000)
+                mdelay(delay / 1000);
+
+        udelay(delay % 1000);
+}
+
 static int tegra_spi_transfer_one_message(struct spi_master *master,
                         struct spi_message *msg)
 {
         bool is_first_msg = true;
-        int single_xfer;
         struct tegra_spi_data *tspi = spi_master_get_devdata(master);
         struct spi_transfer *xfer;
         struct spi_device *spi = msg->spi;
         int ret;
+        bool skip = false;
 
         msg->status = 0;
         msg->actual_length = 0;
 
-        single_xfer = list_is_singular(&msg->transfers);
         list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+                unsigned long cmd1;
+
                 INIT_COMPLETION(tspi->xfer_completion);
-                ret = tegra_spi_start_transfer_one(spi, xfer,
-                                        is_first_msg, single_xfer);
+
+                cmd1 = tegra_spi_setup_transfer_one(spi, xfer, is_first_msg);
+
+                if (!xfer->len) {
+                        ret = 0;
+                        skip = true;
+                        goto complete_xfer;
+                }
+
+                ret = tegra_spi_start_transfer_one(spi, xfer, cmd1);
                 if (ret < 0) {
                         dev_err(tspi->dev,
                                 "spi can not start transfer, err %d\n", ret);
-                        goto exit;
+                        goto complete_xfer;
                 }
+
                 is_first_msg = false;
                 ret = wait_for_completion_timeout(&tspi->xfer_completion,
                                                 SPI_DMA_TIMEOUT);
@@ -833,24 +868,40 @@ static int tegra_spi_transfer_one_message(struct spi_master *master,
                         dev_err(tspi->dev,
                                 "spi trasfer timeout, err %d\n", ret);
                         ret = -EIO;
-                        goto exit;
+                        goto complete_xfer;
                 }
 
                 if (tspi->tx_status ||  tspi->rx_status) {
                         dev_err(tspi->dev, "Error in Transfer\n");
                         ret = -EIO;
-                        goto exit;
+                        goto complete_xfer;
                 }
                 msg->actual_length += xfer->len;
-                if (xfer->cs_change && xfer->delay_usecs) {
+
+complete_xfer:
+                if (ret < 0 || skip) {
                         tegra_spi_writel(tspi, tspi->def_command1_reg,
                                         SPI_COMMAND1);
-                        udelay(xfer->delay_usecs);
+                        tegra_spi_transfer_delay(xfer->delay_usecs);
+                        goto exit;
+                } else if (msg->transfers.prev == &xfer->transfer_list) {
+                        /* This is the last transfer in message */
+                        if (xfer->cs_change)
+                                tspi->cs_control = spi;
+                        else {
+                                tegra_spi_writel(tspi, tspi->def_command1_reg,
+                                                SPI_COMMAND1);
+                                tegra_spi_transfer_delay(xfer->delay_usecs);
+                        }
+                } else if (xfer->cs_change) {
+                        tegra_spi_writel(tspi, tspi->def_command1_reg,
+                                        SPI_COMMAND1);
+                        tegra_spi_transfer_delay(xfer->delay_usecs);
                 }
+
         }
         ret = 0;
 exit:
-        tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1);
         msg->status = ret;
         spi_finalize_current_message(master);
         return ret;