spi: bcm-qspi: Fix bcm_qspi_bspi_read() performance

Let bcm_qspi_bspi_flash_read() return all the requested bytes by breaking
up the reads for BSPI block into optimal chunks size that a BSPI block can
handle.

Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-bcm-qspi.c b/drivers/spi/spi-bcm-qspi.c
index b50b6df..99b3057 100644 (file)
--- a/drivers/spi/spi-bcm-qspi.c
+++ b/drivers/spi/spi-bcm-qspi.c
@@ -89,7 +89,7 @@
 #define BSPI_BPP_MODE_SELECT_MASK              BIT(8)
 #define BSPI_BPP_ADDR_SELECT_MASK              BIT(16)
 
-#define BSPI_READ_LENGTH                       256
+#define BSPI_READ_LENGTH                       512
 
 /* MSPI register offsets */
 #define MSPI_SPCR0_LSB                         0x000
@@ -824,7 +824,7 @@ static int bcm_qspi_bspi_flash_read(struct spi_device *spi,
                                    struct spi_flash_read_message *msg)
 {
        struct bcm_qspi *qspi = spi_master_get_devdata(spi->master);
-       u32 addr = 0, len, len_words;
+       u32 addr = 0, len, rdlen, len_words;
        int ret = 0;
        unsigned long timeo = msecs_to_jiffies(100);
        struct bcm_qspi_soc_intc *soc_intc = qspi->soc_intc;
@@ -837,7 +837,7 @@ static int bcm_qspi_bspi_flash_read(struct spi_device *spi,
        bcm_qspi_write(qspi, MSPI, MSPI_WRITE_LOCK, 0);
 
        /*
-        * when using flex mode mode we need to send
+        * when using flex mode we need to send
         * the upper address byte to bspi
         */
        if (bcm_qspi_bspi_ver_three(qspi) == false) {
@@ -851,47 +851,56 @@ static int bcm_qspi_bspi_flash_read(struct spi_device *spi,
        else
                addr = msg->from & 0x00ffffff;
 
-       /* set BSPI RAF buffer max read length */
-       len = msg->len;
-       if (len > BSPI_READ_LENGTH)
-               len = BSPI_READ_LENGTH;
-
        if (bcm_qspi_bspi_ver_three(qspi) == true)
                addr = (addr + 0xc00000) & 0xffffff;
 
-       reinit_completion(&qspi->bspi_done);
-       bcm_qspi_enable_bspi(qspi);
-       len_words = (len + 3) >> 2;
-       qspi->bspi_rf_msg = msg;
-       qspi->bspi_rf_msg_status = 0;
+       /*
+        * read into the entire buffer by breaking the reads
+        * into RAF buffer read lengths
+        */
+       len = msg->len;
        qspi->bspi_rf_msg_idx = 0;
-       qspi->bspi_rf_msg_len = len;
-       dev_dbg(&qspi->pdev->dev, "bspi xfr addr 0x%x len 0x%x", addr, len);
-
-       bcm_qspi_write(qspi, BSPI, BSPI_RAF_START_ADDR, addr);
-       bcm_qspi_write(qspi, BSPI, BSPI_RAF_NUM_WORDS, len_words);
-       bcm_qspi_write(qspi, BSPI, BSPI_RAF_WATERMARK, 0);
 
-       if (qspi->soc_intc) {
-               /*
-                * clear soc MSPI and BSPI interrupts and enable
-                * BSPI interrupts.
-                */
-               soc_intc->bcm_qspi_int_ack(soc_intc, MSPI_BSPI_DONE);
-               soc_intc->bcm_qspi_int_set(soc_intc, BSPI_DONE, true);
-       }
+       do {
+               if (len > BSPI_READ_LENGTH)
+                       rdlen = BSPI_READ_LENGTH;
+               else
+                       rdlen = len;
+
+               reinit_completion(&qspi->bspi_done);
+               bcm_qspi_enable_bspi(qspi);
+               len_words = (rdlen + 3) >> 2;
+               qspi->bspi_rf_msg = msg;
+               qspi->bspi_rf_msg_status = 0;
+               qspi->bspi_rf_msg_len = rdlen;
+               dev_dbg(&qspi->pdev->dev,
+                       "bspi xfr addr 0x%x len 0x%x", addr, rdlen);
+               bcm_qspi_write(qspi, BSPI, BSPI_RAF_START_ADDR, addr);
+               bcm_qspi_write(qspi, BSPI, BSPI_RAF_NUM_WORDS, len_words);
+               bcm_qspi_write(qspi, BSPI, BSPI_RAF_WATERMARK, 0);
+               if (qspi->soc_intc) {
+                       /*
+                        * clear soc MSPI and BSPI interrupts and enable
+                        * BSPI interrupts.
+                        */
+                       soc_intc->bcm_qspi_int_ack(soc_intc, MSPI_BSPI_DONE);
+                       soc_intc->bcm_qspi_int_set(soc_intc, BSPI_DONE, true);
+               }
 
-       /* Must flush previous writes before starting BSPI operation */
-       mb();
+               /* Must flush previous writes before starting BSPI operation */
+               mb();
+               bcm_qspi_bspi_lr_start(qspi);
+               if (!wait_for_completion_timeout(&qspi->bspi_done, timeo)) {
+                       dev_err(&qspi->pdev->dev, "timeout waiting for BSPI\n");
+                       ret = -ETIMEDOUT;
+                       break;
+               }
 
-       bcm_qspi_bspi_lr_start(qspi);
-       if (!wait_for_completion_timeout(&qspi->bspi_done, timeo)) {
-               dev_err(&qspi->pdev->dev, "timeout waiting for BSPI\n");
-               ret = -ETIMEDOUT;
-       } else {
-               /* set the return length for the caller */
-               msg->retlen = len;
-       }
+               /* set msg return length */
+               msg->retlen += rdlen;
+               addr += rdlen;
+               len -= rdlen;
+       } while (len);
 
        return ret;
 }