1 files changed, 36 insertions, 7 deletions

diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index 965539b0dbfb..8f0afdb067b8 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -45,6 +45,7 @@
 #include <linux/platform_data/spi-omap2-mcspi.h>
 
 #define OMAP2_MCSPI_MAX_FREQ            48000000
+#define OMAP2_MCSPI_MAX_DIVIDER         4096
 #define OMAP2_MCSPI_MAX_FIFODEPTH       64
 #define OMAP2_MCSPI_MAX_FIFOWCNT        0xFFFF
 #define SPI_AUTOSUSPEND_TIMEOUT         2000
@@ -89,6 +90,7 @@
 #define OMAP2_MCSPI_CHCONF_FORCE        BIT(20)
 #define OMAP2_MCSPI_CHCONF_FFET         BIT(27)
 #define OMAP2_MCSPI_CHCONF_FFER         BIT(28)
+#define OMAP2_MCSPI_CHCONF_CLKG         BIT(29)
 
 #define OMAP2_MCSPI_CHSTAT_RXS          BIT(0)
 #define OMAP2_MCSPI_CHSTAT_TXS          BIT(1)
@@ -96,6 +98,7 @@
 #define OMAP2_MCSPI_CHSTAT_TXFFE        BIT(3)
 
 #define OMAP2_MCSPI_CHCTRL_EN           BIT(0)
+#define OMAP2_MCSPI_CHCTRL_EXTCLK_MASK  (0xff << 8)
 
 #define OMAP2_MCSPI_WAKEUPENABLE_WKEN   BIT(0)
 
@@ -149,7 +152,7 @@ struct omap2_mcspi_cs {
         int                     word_len;
         struct list_head        node;
         /* Context save and restore shadow register */
-        u32                     chconf0;
+        u32                     chconf0, chctrl0;
 };
 
 static inline void mcspi_write_reg(struct spi_master *master,
@@ -230,10 +233,16 @@ static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
 
 static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
 {
+        struct omap2_mcspi_cs *cs = spi->controller_state;
         u32 l;
 
-        l = enable ? OMAP2_MCSPI_CHCTRL_EN : 0;
-        mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, l);
+        l = cs->chctrl0;
+        if (enable)
+                l |= OMAP2_MCSPI_CHCTRL_EN;
+        else
+                l &= ~OMAP2_MCSPI_CHCTRL_EN;
+        cs->chctrl0 = l;
+        mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
         /* Flash post-writes */
         mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
 }
@@ -840,7 +849,7 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
         struct omap2_mcspi_cs *cs = spi->controller_state;
         struct omap2_mcspi *mcspi;
         struct spi_master *spi_cntrl;
-        u32 l = 0, div = 0;
+        u32 l = 0, clkd = 0, div, extclk = 0, clkg = 0;
         u8 word_len = spi->bits_per_word;
         u32 speed_hz = spi->max_speed_hz;
 
@@ -856,7 +865,17 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
                 speed_hz = t->speed_hz;
 
         speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
-        div = omap2_mcspi_calc_divisor(speed_hz);
+        if (speed_hz < (OMAP2_MCSPI_MAX_FREQ / OMAP2_MCSPI_MAX_DIVIDER)) {
+                clkd = omap2_mcspi_calc_divisor(speed_hz);
+                speed_hz = OMAP2_MCSPI_MAX_FREQ >> clkd;
+                clkg = 0;
+        } else {
+                div = (OMAP2_MCSPI_MAX_FREQ + speed_hz - 1) / speed_hz;
+                speed_hz = OMAP2_MCSPI_MAX_FREQ / div;
+                clkd = (div - 1) & 0xf;
+                extclk = (div - 1) >> 4;
+                clkg = OMAP2_MCSPI_CHCONF_CLKG;
+        }
 
         l = mcspi_cached_chconf0(spi);
 
@@ -885,7 +904,16 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
 
         /* set clock divisor */
         l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
-        l |= div << 2;
+        l |= clkd << 2;
+
+        /* set clock granularity */
+        l &= ~OMAP2_MCSPI_CHCONF_CLKG;
+        l |= clkg;
+        if (clkg) {
+                cs->chctrl0 &= ~OMAP2_MCSPI_CHCTRL_EXTCLK_MASK;
+                cs->chctrl0 |= extclk << 8;
+                mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
+        }
 
         /* set SPI mode 0..3 */
         if (spi->mode & SPI_CPOL)
@@ -900,7 +928,7 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
         mcspi_write_chconf0(spi, l);
 
         dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
-                        OMAP2_MCSPI_MAX_FREQ >> div,
+                        speed_hz,
                         (spi->mode & SPI_CPHA) ? "trailing" : "leading",
                         (spi->mode & SPI_CPOL) ? "inverted" : "normal");
 
@@ -972,6 +1000,7 @@ static int omap2_mcspi_setup(struct spi_device *spi)
                 cs->base = mcspi->base + spi->chip_select * 0x14;
                 cs->phys = mcspi->phys + spi->chip_select * 0x14;
                 cs->chconf0 = 0;
+                cs->chctrl0 = 0;
                 spi->controller_state = cs;
                 /* Link this to context save list */
                 list_add_tail(&cs->node, &ctx->cs);