spi_mpc83xx: use brg-frequency for SPI in QE
Anton Vorontsov [Thu, 24 Jan 2008 15:40:03 +0000 (18:40 +0300)]
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>

arch/powerpc/sysdev/fsl_soc.c
drivers/spi/spi_mpc83xx.c

index 26f7d83..6f81dd5 100644 (file)
@@ -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)
index 4580b9c..04f7cd9 100644 (file)
@@ -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;