TI Davinci: add a pin multiplexer configuration API

Creates a method allowing pin settings to be logically grouped into data
structure arrays and provides an API to configure the pinmux settings to
enable the relevant pin functions.

Signed-off-by: Nick Thompson <nick.thompson@gefanuc.com>

diff --git a/board/davinci/common/misc.c b/board/davinci/common/misc.c
index ffdc20b..9fab76f 100644 (file)
--- a/board/davinci/common/misc.c
+++ b/board/davinci/common/misc.c
@@ -1,6 +1,7 @@
 /*
  * Miscelaneous DaVinci functions.
  *
+ * Copyright (C) 2009 Nick Thompson, GE Fanuc Ltd, <nick.thompson@gefanuc.com>
  * Copyright (C) 2007 Sergey Kubushyn <ksi@koi8.net>
  * Copyright (C) 2008 Lyrtech <www.lyrtech.com>
  * Copyright (C) 2004 Texas Instruments.
@@ -27,7 +28,8 @@
 #include <i2c.h>
 #include <net.h>
 #include <asm/arch/hardware.h>
-
+#include <asm/io.h>
+#include "misc.h"
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -109,3 +111,47 @@ void dv_configure_mac_address(uint8_t *rom_enetaddr)
 }
 
 #endif /* DAVINCI_EMAC */
+
+/*
+ * Change the setting of a pin multiplexer field.
+ *
+ * Takes an array of pinmux settings similar to:
+ *
+ * struct pinmux_config uart_pins[] = {
+ *     { &davinci_syscfg_regs->pinmux[8], 2, 7 },
+ *     { &davinci_syscfg_regs->pinmux[9], 2, 0 }
+ * };
+ *
+ * Stepping through the array, each pinmux[n] register has the given value
+ * set in the pin mux field specified.
+ *
+ * The number of pins in the array must be passed (ARRAY_SIZE can provide
+ * this value conveniently).
+ *
+ * Returns 0 if all field numbers and values are in the correct range,
+ * else returns -1.
+ */
+int davinci_configure_pin_mux(const struct pinmux_config *pins,
+                             const int n_pins)
+{
+       int i;
+
+       /* check for invalid pinmux values */
+       for (i = 0; i < n_pins; i++) {
+               if (pins[i].field >= PIN_MUX_NUM_FIELDS ||
+                   (pins[i].value & ~PIN_MUX_FIELD_MASK) != 0)
+                       return -1;
+       }
+
+       /* configure the pinmuxes */
+       for (i = 0; i < n_pins; i++) {
+               const int offset = pins[i].field * PIN_MUX_FIELD_SIZE;
+               const unsigned int value = pins[i].value << offset;
+               const unsigned int mask = PIN_MUX_FIELD_MASK << offset;
+               const dv_reg *mux = pins[i].mux;
+
+               writel(value | (readl(mux) & (~mask)), mux);
+       }
+
+       return 0;
+}

diff --git a/board/davinci/common/misc.h b/board/davinci/common/misc.h
index dc3cc41..f6d8b1b 100644 (file)
--- a/board/davinci/common/misc.h
+++ b/board/davinci/common/misc.h
@@ -22,8 +22,20 @@
 #ifndef __MISC_H
 #define __MISC_H
 
+/* pin muxer definitions */
+#define PIN_MUX_NUM_FIELDS     8       /* Per register */
+#define PIN_MUX_FIELD_SIZE     4       /* n in bits */
+#define PIN_MUX_FIELD_MASK     ((1 << PIN_MUX_FIELD_SIZE) - 1)
+
+/* pin definition */
+struct pinmux_config {
+       dv_reg          *mux;           /* Address of mux register */
+       unsigned char   value;          /* Value to set in field */
+       unsigned char   field;          /* field number */
+};
 
 int dvevm_read_mac_address(uint8_t *buf);
 void dv_configure_mac_address(uint8_t *rom_enetaddr);
+int davinci_configure_pin_mux(const struct pinmux_config *pins, int n_pins);
 
 #endif /* __MISC_H */