[POWERPC] Add common clock setting routine mpc52xx_psc_set_clkdiv()

PSC drivers should not access the CDM registers directly.  Instead provide
a common routine for setting the PSC clock parameters with the required
locking.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 36 insertions, 0 deletions

diff --git a/arch/ppc/syslib/mpc52xx_setup.c b/arch/ppc/syslib/mpc52xx_setup.c
index ecfa2c0f8ba..9f504fc7693 100644
--- a/arch/ppc/syslib/mpc52xx_setup.c
+++ b/arch/ppc/syslib/mpc52xx_setup.c
@@ -16,6 +16,7 @@
  */
 
 
+#include <linux/spinlock.h>
 #include <asm/io.h>
 #include <asm/time.h>
 #include <asm/mpc52xx.h>
@@ -275,3 +276,38 @@ int mpc52xx_match_psc_function(int psc_idx, const char *func)
 
         return 0;
 }
+
+int mpc52xx_set_psc_clkdiv(int psc_id, int clkdiv)
+{
+        static spinlock_t lock = SPIN_LOCK_UNLOCKED;
+        struct mpc52xx_cdm __iomem *cdm;
+        unsigned long flags;
+        u16 mclken_div;
+        u16 __iomem *reg;
+        u32 mask;
+
+        cdm = ioremap(MPC52xx_PA(MPC52xx_CDM_OFFSET), MPC52xx_CDM_SIZE);
+        if (!cdm) {
+                printk(KERN_ERR __FILE__ ": Error mapping CDM\n");
+                return -ENODEV;
+        }
+
+        mclken_div = 0x8000 | (clkdiv & 0x1FF);
+        switch (psc_id) {
+        case 1: reg = &cdm->mclken_div_psc1; mask = 0x20; break;
+        case 2: reg = &cdm->mclken_div_psc2; mask = 0x40; break;
+        case 3: reg = &cdm->mclken_div_psc3; mask = 0x80; break;
+        case 6: reg = &cdm->mclken_div_psc6; mask = 0x10; break;
+        default:
+                return -ENODEV;
+        }
+
+        /* Set the rate and enable the clock */
+        spin_lock_irqsave(&lock, flags);
+        out_be16(reg, mclken_div);
+        out_be32(&cdm->clk_enables, in_be32(&cdm->clk_enables) | mask);
+        spin_unlock_irqrestore(&lock, flags);
+
+        iounmap(cdm);
+        return 0;
+}