1 files changed, 44 insertions, 20 deletions

diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index 94f133cb2770..2941c5b96ebc 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -44,6 +44,7 @@
 #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
@@ -88,6 +89,7 @@
 #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)
@@ -95,6 +97,7 @@
 #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)
 
@@ -148,7 +151,7 @@ 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,
@@ -229,10 +232,16 @@ 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);
 }
@@ -839,7 +848,7 @@ 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;
 
@@ -855,7 +864,17 @@ 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);
 
@@ -884,7 +903,16 @@ 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)
@@ -899,7 +927,7 @@ 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");
 
@@ -971,6 +999,7 @@ 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);
@@ -1056,12 +1085,15 @@ static void omap2_mcspi_work(struct omap2_mcspi *mcspi, struct spi_message *m)
                         status = -EINVAL;
                         break;
                 }
-                if (par_override || t->speed_hz || t->bits_per_word) {
+                if (par_override ||
+                    (t->speed_hz != spi->max_speed_hz) ||
+                    (t->bits_per_word != spi->bits_per_word)) {
                         par_override = 1;
                         status = omap2_mcspi_setup_transfer(spi, t);
                         if (status < 0)
                                 break;
-                        if (!t->speed_hz && !t->bits_per_word)
+                        if (t->speed_hz == spi->max_speed_hz &&
+                            t->bits_per_word == spi->bits_per_word)
                                 par_override = 0;
                 }
                 if (cd && cd->cs_per_word) {
@@ -1175,16 +1207,12 @@ static int omap2_mcspi_transfer_one_message(struct spi_master *master,
         m->actual_length = 0;
         m->status = 0;
 
-        /* reject invalid messages and transfers */
-        if (list_empty(&m->transfers))
-                return -EINVAL;
         list_for_each_entry(t, &m->transfers, transfer_list) {
                 const void      *tx_buf = t->tx_buf;
                 void            *rx_buf = t->rx_buf;
                 unsigned        len = t->len;
 
-                if (t->speed_hz > OMAP2_MCSPI_MAX_FREQ
-                                || (len && !(rx_buf || tx_buf))) {
+                if ((len && !(rx_buf || tx_buf))) {
                         dev_dbg(mcspi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
                                         t->speed_hz,
                                         len,
@@ -1193,12 +1221,6 @@ static int omap2_mcspi_transfer_one_message(struct spi_master *master,
                                         t->bits_per_word);
                         return -EINVAL;
                 }
-                if (t->speed_hz && t->speed_hz < (OMAP2_MCSPI_MAX_FREQ >> 15)) {
-                        dev_dbg(mcspi->dev, "speed_hz %d below minimum %d Hz\n",
-                                        t->speed_hz,
-                                        OMAP2_MCSPI_MAX_FREQ >> 15);
-                        return -EINVAL;
-                }
 
                 if (m->is_dma_mapped || len < DMA_MIN_BYTES)
                         continue;
@@ -1310,6 +1332,8 @@ static int omap2_mcspi_probe(struct platform_device *pdev)
         master->transfer_one_message = omap2_mcspi_transfer_one_message;
         master->cleanup = omap2_mcspi_cleanup;
         master->dev.of_node = node;
+        master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ;
+        master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15;
 
         platform_set_drvdata(pdev, master);