spi: mediatek: skip delays if they are 0

In the function 'mtk_spi_set_hw_cs_timing'
the 'setup', 'hold' and 'inactive' delays are configured.
In case those values are 0 it causes errors on mt8173:

cros-ec-i2c-tunnel 1100a000.spi:ec@0:i2c-tunnel0:
	Error transferring EC i2c message -71
cros-ec-spi spi0.0: EC failed to respond in time.

This patch fixes that issues by setting only the values
that are not 0.

Fixes: 04e6bb0d6bb1 ("spi: modify set_cs_timing parameter")
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Link: https://lore.kernel.org/r/20211001152153.4604-1-dafna.hirschfeld@collabora.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index 386e8c8..a15de10 100644 (file)
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -233,36 +233,44 @@ static int mtk_spi_set_hw_cs_timing(struct spi_device *spi)
                return delay;
        inactive = (delay * DIV_ROUND_UP(mdata->spi_clk_hz, 1000000)) / 1000;
 
-       setup    = setup ? setup : 1;
-       hold     = hold ? hold : 1;
-       inactive = inactive ? inactive : 1;
-
-       reg_val = readl(mdata->base + SPI_CFG0_REG);
-       if (mdata->dev_comp->enhance_timing) {
-               hold = min_t(u32, hold, 0x10000);
-               setup = min_t(u32, setup, 0x10000);
-               reg_val &= ~(0xffff << SPI_ADJUST_CFG0_CS_HOLD_OFFSET);
-               reg_val |= (((hold - 1) & 0xffff)
-                          << SPI_ADJUST_CFG0_CS_HOLD_OFFSET);
-               reg_val &= ~(0xffff << SPI_ADJUST_CFG0_CS_SETUP_OFFSET);
-               reg_val |= (((setup - 1) & 0xffff)
-                          << SPI_ADJUST_CFG0_CS_SETUP_OFFSET);
-       } else {
-               hold = min_t(u32, hold, 0x100);
-               setup = min_t(u32, setup, 0x100);
-               reg_val &= ~(0xff << SPI_CFG0_CS_HOLD_OFFSET);
-               reg_val |= (((hold - 1) & 0xff) << SPI_CFG0_CS_HOLD_OFFSET);
-               reg_val &= ~(0xff << SPI_CFG0_CS_SETUP_OFFSET);
-               reg_val |= (((setup - 1) & 0xff)
-                           << SPI_CFG0_CS_SETUP_OFFSET);
+       if (hold || setup) {
+               reg_val = readl(mdata->base + SPI_CFG0_REG);
+               if (mdata->dev_comp->enhance_timing) {
+                       if (hold) {
+                               hold = min_t(u32, hold, 0x10000);
+                               reg_val &= ~(0xffff << SPI_ADJUST_CFG0_CS_HOLD_OFFSET);
+                               reg_val |= (((hold - 1) & 0xffff)
+                                       << SPI_ADJUST_CFG0_CS_HOLD_OFFSET);
+                       }
+                       if (setup) {
+                               setup = min_t(u32, setup, 0x10000);
+                               reg_val &= ~(0xffff << SPI_ADJUST_CFG0_CS_SETUP_OFFSET);
+                               reg_val |= (((setup - 1) & 0xffff)
+                                       << SPI_ADJUST_CFG0_CS_SETUP_OFFSET);
+                       }
+               } else {
+                       if (hold) {
+                               hold = min_t(u32, hold, 0x100);
+                               reg_val &= ~(0xff << SPI_CFG0_CS_HOLD_OFFSET);
+                               reg_val |= (((hold - 1) & 0xff) << SPI_CFG0_CS_HOLD_OFFSET);
+                       }
+                       if (setup) {
+                               setup = min_t(u32, setup, 0x100);
+                               reg_val &= ~(0xff << SPI_CFG0_CS_SETUP_OFFSET);
+                               reg_val |= (((setup - 1) & 0xff)
+                                       << SPI_CFG0_CS_SETUP_OFFSET);
+                       }
+               }
+               writel(reg_val, mdata->base + SPI_CFG0_REG);
        }
-       writel(reg_val, mdata->base + SPI_CFG0_REG);
 
-       inactive = min_t(u32, inactive, 0x100);
-       reg_val = readl(mdata->base + SPI_CFG1_REG);
-       reg_val &= ~SPI_CFG1_CS_IDLE_MASK;
-       reg_val |= (((inactive - 1) & 0xff) << SPI_CFG1_CS_IDLE_OFFSET);
-       writel(reg_val, mdata->base + SPI_CFG1_REG);
+       if (inactive) {
+               inactive = min_t(u32, inactive, 0x100);
+               reg_val = readl(mdata->base + SPI_CFG1_REG);
+               reg_val &= ~SPI_CFG1_CS_IDLE_MASK;
+               reg_val |= (((inactive - 1) & 0xff) << SPI_CFG1_CS_IDLE_OFFSET);
+               writel(reg_val, mdata->base + SPI_CFG1_REG);
+       }
 
        return 0;
 }