spi_mpc83xx: use brg-frequency for SPI in QE

In case of QE we can use brg-frequency (which is qeclk/2).
Thus no need to divide sysclk in the spi_mpc83xx.

This patch also adds code to use get_brgfreq() on QE chips.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

2 files changed, 34 insertions, 18 deletions

diff --git a/arch/powerpc/sysdev/fsl_soc.c b/arch/powerpc/sysdev/fsl_soc.c
index 26f7d83c4be5..6f81dd5eb6d4 100644
--- a/arch/powerpc/sysdev/fsl_soc.c
+++ b/arch/powerpc/sysdev/fsl_soc.c
@@ -75,7 +75,7 @@ phys_addr_t get_immrbase(void)
 
 EXPORT_SYMBOL(get_immrbase);
 
-#if defined(CONFIG_CPM2) || defined(CONFIG_8xx)
+#if defined(CONFIG_CPM2) || defined(CONFIG_QUICC_ENGINE) || defined(CONFIG_8xx)
 
 static u32 brgfreq = -1;
 
@@ -100,11 +100,21 @@ u32 get_brgfreq(void)
 
         /* Legacy device binding -- will go away when no users are left. */
         node = of_find_node_by_type(NULL, "cpm");
+        if (!node)
+                node = of_find_compatible_node(NULL, NULL, "fsl,qe");
+        if (!node)
+                node = of_find_node_by_type(NULL, "qe");
+
         if (node) {
                 prop = of_get_property(node, "brg-frequency", &size);
                 if (prop && size == 4)
                         brgfreq = *prop;
 
+                if (brgfreq == -1 || brgfreq == 0) {
+                        prop = of_get_property(node, "bus-frequency", &size);
+                        if (prop && size == 4)
+                                brgfreq = *prop / 2;
+                }
                 of_node_put(node);
         }
 
@@ -1273,22 +1283,32 @@ int __init fsl_spi_init(struct spi_board_info *board_infos,
 {
         struct device_node *np;
         unsigned int i;
-        const u32 *sysclk;
+        u32 sysclk = -1;
 
         /* SPI controller is either clocked from QE or SoC clock */
-        np = of_find_compatible_node(NULL, NULL, "fsl,qe");
-        if (!np)
-                np = of_find_node_by_type(NULL, "qe");
+#ifdef CONFIG_QUICC_ENGINE
+        sysclk = get_brgfreq();
+#endif
+        if (sysclk == -1) {
+                const u32 *freq;
+                int size;
 
-        if (!np)
                 np = of_find_node_by_type(NULL, "soc");
+                if (!np)
+                        return -ENODEV;
+
+                freq = of_get_property(np, "clock-frequency", &size);
+                if (!freq || size != sizeof(*freq) || *freq == 0) {
+                        freq = of_get_property(np, "bus-frequency", &size);
+                        if (!freq || size != sizeof(*freq) || *freq == 0) {
+                                of_node_put(np);
+                                return -ENODEV;
+                        }
+                }
 
-        if (!np)
-                return -ENODEV;
-
-        sysclk = of_get_property(np, "bus-frequency", NULL);
-        if (!sysclk)
-                return -ENODEV;
+                sysclk = *freq;
+                of_node_put(np);
+        }
 
         for (np = NULL, i = 1;
              (np = of_find_compatible_node(np, "spi", "fsl_spi")) != NULL;
@@ -1305,7 +1325,7 @@ int __init fsl_spi_init(struct spi_board_info *board_infos,
 
                 memset(res, 0, sizeof(res));
 
-                pdata.sysclk = *sysclk;
+                pdata.sysclk = sysclk;
 
                 prop = of_get_property(np, "reg", NULL);
                 if (!prop)
diff --git a/drivers/spi/spi_mpc83xx.c b/drivers/spi/spi_mpc83xx.c
index 4580b9cf625d..04f7cd9fc261 100644
--- a/drivers/spi/spi_mpc83xx.c
+++ b/drivers/spi/spi_mpc83xx.c
@@ -436,11 +436,7 @@ static int __init mpc83xx_spi_probe(struct platform_device *dev)
         mpc83xx_spi->qe_mode = pdata->qe_mode;
         mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u8;
         mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u8;
-
-        if (mpc83xx_spi->qe_mode)
-                mpc83xx_spi->spibrg = pdata->sysclk / 2;
-        else
-                mpc83xx_spi->spibrg = pdata->sysclk;
+        mpc83xx_spi->spibrg = pdata->sysclk;
 
         mpc83xx_spi->rx_shift = 0;
         mpc83xx_spi->tx_shift = 0;