spi: sh-msiof: Configure MSIOF sync signal timing in device tree

The MSIOF controller has DTDL and SYNCDL in SITMDR1 register. So,
this patch adds new properties like the following commit:
  d0fb47a5237d8b9576113568bacfd27892308b62
  (spi: fsl-espi: Configure FSL eSPI CSBEF and CSAFT)

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

3 files changed, 65 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/spi/sh-msiof.txt b/Documentation/devicetree/bindings/spi/sh-msiof.txt
index d11c3721e7cd..4c388bb2f0a2 100644
--- a/Documentation/devicetree/bindings/spi/sh-msiof.txt
+++ b/Documentation/devicetree/bindings/spi/sh-msiof.txt
@@ -30,6 +30,22 @@ Optional properties:
                          specifiers, one for transmission, and one for
                          reception.
 - dma-names            : Must contain a list of two DMA names, "tx" and "rx".
+- renesas,dtdl         : delay sync signal (setup) in transmit mode.
+                         Must contain one of the following values:
+                         0   (no bit delay)
+                         50  (0.5-clock-cycle delay)
+                         100 (1-clock-cycle delay)
+                         150 (1.5-clock-cycle delay)
+                         200 (2-clock-cycle delay)
+
+- renesas,syncdl       : delay sync signal (hold) in transmit mode.
+                         Must contain one of the following values:
+                         0   (no bit delay)
+                         50  (0.5-clock-cycle delay)
+                         100 (1-clock-cycle delay)
+                         150 (1.5-clock-cycle delay)
+                         200 (2-clock-cycle delay)
+                         300 (3-clock-cycle delay)
 
 Optional properties, deprecated for soctype-specific bindings:
 - renesas,tx-fifo-size : Overrides the default tx fifo size given in words
diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c
index 239be7cbe5a8..2a87cb939f56 100644
--- a/drivers/spi/spi-sh-msiof.c
+++ b/drivers/spi/spi-sh-msiof.c
@@ -82,6 +82,8 @@ struct sh_msiof_spi_priv {
 #define MDR1_SYNCMD_LR   0x30000000 /*   L/R mode */
 #define MDR1_SYNCAC_SHIFT        25 /* Sync Polarity (1 = Active-low) */
 #define MDR1_BITLSB_SHIFT        24 /* MSB/LSB First (1 = LSB first) */
+#define MDR1_DTDL_SHIFT          20 /* Data Pin Bit Delay for MSIOF_SYNC */
+#define MDR1_SYNCDL_SHIFT        16 /* Frame Sync Signal Timing Delay */
 #define MDR1_FLD_MASK    0x000000c0 /* Frame Sync Signal Interval (0-3) */
 #define MDR1_FLD_SHIFT            2
 #define MDR1_XXSTP       0x00000001 /* Transmission/Reception Stop on FIFO */
@@ -279,6 +281,48 @@ static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p,
                 sh_msiof_write(p, RSCR, sh_msiof_spi_clk_table[k].scr);
 }
 
+static u32 sh_msiof_get_delay_bit(u32 dtdl_or_syncdl)
+{
+        /*
+         * DTDL/SYNCDL bit      : p->info->dtdl or p->info->syncdl
+         * b'000                : 0
+         * b'001                : 100
+         * b'010                : 200
+         * b'011 (SYNCDL only)  : 300
+         * b'101                : 50
+         * b'110                : 150
+         */
+        if (dtdl_or_syncdl % 100)
+                return dtdl_or_syncdl / 100 + 5;
+        else
+                return dtdl_or_syncdl / 100;
+}
+
+static u32 sh_msiof_spi_get_dtdl_and_syncdl(struct sh_msiof_spi_priv *p)
+{
+        u32 val;
+
+        if (!p->info)
+                return 0;
+
+        /* check if DTDL and SYNCDL is allowed value */
+        if (p->info->dtdl > 200 || p->info->syncdl > 300) {
+                dev_warn(&p->pdev->dev, "DTDL or SYNCDL is too large\n");
+                return 0;
+        }
+
+        /* check if the sum of DTDL and SYNCDL becomes an integer value  */
+        if ((p->info->dtdl + p->info->syncdl) % 100) {
+                dev_warn(&p->pdev->dev, "the sum of DTDL/SYNCDL is not good\n");
+                return 0;
+        }
+
+        val = sh_msiof_get_delay_bit(p->info->dtdl) << MDR1_DTDL_SHIFT;
+        val |= sh_msiof_get_delay_bit(p->info->syncdl) << MDR1_SYNCDL_SHIFT;
+
+        return val;
+}
+
 static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
                                       u32 cpol, u32 cpha,
                                       u32 tx_hi_z, u32 lsb_first, u32 cs_high)
@@ -296,6 +340,7 @@ static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
         tmp = MDR1_SYNCMD_SPI | 1 << MDR1_FLD_SHIFT | MDR1_XXSTP;
         tmp |= !cs_high << MDR1_SYNCAC_SHIFT;
         tmp |= lsb_first << MDR1_BITLSB_SHIFT;
+        tmp |= sh_msiof_spi_get_dtdl_and_syncdl(p);
         sh_msiof_write(p, TMDR1, tmp | MDR1_TRMD | TMDR1_PCON);
         if (p->chipdata->master_flags & SPI_MASTER_MUST_TX) {
                 /* These bits are reserved if RX needs TX */
@@ -952,6 +997,8 @@ static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
                                         &info->tx_fifo_override);
         of_property_read_u32(np, "renesas,rx-fifo-size",
                                         &info->rx_fifo_override);
+        of_property_read_u32(np, "renesas,dtdl", &info->dtdl);
+        of_property_read_u32(np, "renesas,syncdl", &info->syncdl);
 
         info->num_chipselect = num_cs;
 
diff --git a/include/linux/spi/sh_msiof.h b/include/linux/spi/sh_msiof.h
index 88a14d81c49e..b087a85f5f72 100644
--- a/include/linux/spi/sh_msiof.h
+++ b/include/linux/spi/sh_msiof.h
@@ -7,6 +7,8 @@ struct sh_msiof_spi_info {
         u16 num_chipselect;
         unsigned int dma_tx_id;
         unsigned int dma_rx_id;
+        u32 dtdl;
+        u32 syncdl;
 };
 
 #endif /* __SPI_SH_MSIOF_H__ */