spi: McSPI saves CHCONFx too

Previous restore was lazy and only restored CHxCONF when it was needed by
a specific chip select.  This could cause occasional errors on an SPI bus
where multiple chip selects are in use.

Signed-off-by: Tero Kristo <tero.kristo@nokia.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c
index e96ad2709565..85b7aea73374 100644
--- a/drivers/spi/omap2_mcspi.c
+++ b/drivers/spi/omap2_mcspi.c
@@ -134,6 +134,7 @@ struct omap2_mcspi_cs {
         void __iomem            *base;
         unsigned long           phys;
         int                     word_len;
+        struct list_head        node;
         /* Context save and restore shadow register */
         u32                     chconf0;
 };
@@ -145,6 +146,7 @@ struct omap2_mcspi_regs {
         u32 sysconfig;
         u32 modulctrl;
         u32 wakeupenable;
+        struct list_head cs;
 };
 
 static struct omap2_mcspi_regs omap2_mcspi_ctx[OMAP2_MCSPI_MAX_CTRL];
@@ -255,6 +257,7 @@ static void omap2_mcspi_set_master_mode(struct spi_master *master)
 static void omap2_mcspi_restore_ctx(struct omap2_mcspi *mcspi)
 {
         struct spi_master *spi_cntrl;
+        struct omap2_mcspi_cs *cs;
         spi_cntrl = mcspi->master;
 
         /* McSPI: context restore */
@@ -266,6 +269,10 @@ static void omap2_mcspi_restore_ctx(struct omap2_mcspi *mcspi)
 
         mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_WAKEUPENABLE,
                         omap2_mcspi_ctx[spi_cntrl->bus_num - 1].wakeupenable);
+
+        list_for_each_entry(cs, &omap2_mcspi_ctx[spi_cntrl->bus_num - 1].cs,
+                        node)
+                __raw_writel(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
 }
 static void omap2_mcspi_disable_clocks(struct omap2_mcspi *mcspi)
 {
@@ -714,6 +721,9 @@ static int omap2_mcspi_setup(struct spi_device *spi)
                 cs->phys = mcspi->phys + spi->chip_select * 0x14;
                 cs->chconf0 = 0;
                 spi->controller_state = cs;
+                /* Link this to context save list */
+                list_add_tail(&cs->node,
+                        &omap2_mcspi_ctx[mcspi->master->bus_num - 1].cs);
         }
 
         if (mcspi_dma->dma_rx_channel == -1
@@ -736,10 +746,15 @@ static void omap2_mcspi_cleanup(struct spi_device *spi)
 {
         struct omap2_mcspi      *mcspi;
         struct omap2_mcspi_dma  *mcspi_dma;
+        struct omap2_mcspi_cs   *cs;
 
         mcspi = spi_master_get_devdata(spi->master);
         mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 
+        /* Unlink controller state from context save list */
+        cs = spi->controller_state;
+        list_del(&cs->node);
+
         kfree(spi->controller_state);
 
         if (mcspi_dma->dma_rx_channel != -1) {
@@ -1104,6 +1119,7 @@ static int __init omap2_mcspi_probe(struct platform_device *pdev)
 
         spin_lock_init(&mcspi->lock);
         INIT_LIST_HEAD(&mcspi->msg_queue);
+        INIT_LIST_HEAD(&omap2_mcspi_ctx[master->bus_num - 1].cs);
 
         mcspi->ick = clk_get(&pdev->dev, "ick");
         if (IS_ERR(mcspi->ick)) {