[POWERPC] fsl_lbc: implement few UPM routines

Freescale UPM can be used to adjust localbus timings or to generate
orbitrary, pre-programmed "patterns" on the external Localbus signals.
This patch implements few routines so drivers could work with UPMs in
safe and generic manner.

So far there is just one user of these routines: Freescale UPM NAND
driver.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 129 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/fsl_lbc.c b/arch/powerpc/sysdev/fsl_lbc.c
new file mode 100644
index 00000000000..422c8faef59
--- /dev/null
+++ b/arch/powerpc/sysdev/fsl_lbc.c
@@ -0,0 +1,129 @@
+/*
+ * Freescale LBC and UPM routines.
+ *
+ * Copyright (c) 2007-2008  MontaVista Software, Inc.
+ *
+ * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <asm/fsl_lbc.h>
+
+spinlock_t fsl_lbc_lock = __SPIN_LOCK_UNLOCKED(fsl_lbc_lock);
+
+struct fsl_lbc_regs __iomem *fsl_lbc_regs;
+EXPORT_SYMBOL(fsl_lbc_regs);
+
+static char __initdata *compat_lbc[] = {
+        "fsl,pq2-localbus",
+        "fsl,pq2pro-localbus",
+        "fsl,pq3-localbus",
+        "fsl,elbc",
+};
+
+static int __init fsl_lbc_init(void)
+{
+        struct device_node *lbus;
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(compat_lbc); i++) {
+                lbus = of_find_compatible_node(NULL, NULL, compat_lbc[i]);
+                if (lbus)
+                        goto found;
+        }
+        return -ENODEV;
+
+found:
+        fsl_lbc_regs = of_iomap(lbus, 0);
+        of_node_put(lbus);
+        if (!fsl_lbc_regs)
+                return -ENOMEM;
+        return 0;
+}
+arch_initcall(fsl_lbc_init);
+
+/**
+ * fsl_lbc_find - find Localbus bank
+ * @addr_base:  base address of the memory bank
+ *
+ * This function walks LBC banks comparing "Base address" field of the BR
+ * registers with the supplied addr_base argument. When bases match this
+ * function returns bank number (starting with 0), otherwise it returns
+ * appropriate errno value.
+ */
+int fsl_lbc_find(phys_addr_t addr_base)
+{
+        int i;
+
+        if (!fsl_lbc_regs)
+                return -ENODEV;
+
+        for (i = 0; i < ARRAY_SIZE(fsl_lbc_regs->bank); i++) {
+                __be32 br = in_be32(&fsl_lbc_regs->bank[i].br);
+                __be32 or = in_be32(&fsl_lbc_regs->bank[i].or);
+
+                if (br & BR_V && (br & or & BR_BA) == addr_base)
+                        return i;
+        }
+
+        return -ENOENT;
+}
+EXPORT_SYMBOL(fsl_lbc_find);
+
+/**
+ * fsl_upm_find - find pre-programmed UPM via base address
+ * @addr_base:  base address of the memory bank controlled by the UPM
+ * @upm:        pointer to the allocated fsl_upm structure
+ *
+ * This function fills fsl_upm structure so you can use it with the rest of
+ * UPM API. On success this function returns 0, otherwise it returns
+ * appropriate errno value.
+ */
+int fsl_upm_find(phys_addr_t addr_base, struct fsl_upm *upm)
+{
+        int bank;
+        __be32 br;
+
+        bank = fsl_lbc_find(addr_base);
+        if (bank < 0)
+                return bank;
+
+        br = in_be32(&fsl_lbc_regs->bank[bank].br);
+
+        switch (br & BR_MSEL) {
+        case BR_MS_UPMA:
+                upm->mxmr = &fsl_lbc_regs->mamr;
+                break;
+        case BR_MS_UPMB:
+                upm->mxmr = &fsl_lbc_regs->mbmr;
+                break;
+        case BR_MS_UPMC:
+                upm->mxmr = &fsl_lbc_regs->mcmr;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        switch (br & BR_PS) {
+        case BR_PS_8:
+                upm->width = 8;
+                break;
+        case BR_PS_16:
+                upm->width = 16;
+                break;
+        case BR_PS_32:
+                upm->width = 32;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        return 0;
+}
+EXPORT_SYMBOL(fsl_upm_find);