gpio: Add Multi-Function-Pin configuration driver for Marvell SoCs

Most of the Marvell SoCs has Multi Function Pin (MFP) configuration registers
For ex. ARMADA100.

These registers are programmed to expose the specific functionality
associated with respective SoC Pins

This driver provides configuration APIs,
using them, configuration need to be done in board specific code

for ex- following code configures MFPs 107 and 108 for UART_TX/RX functionality

int board_early_init_f(void)
{
        u32 mfp_cfg[] = {
                /* Console on UART1 */
                MFP107_UART1_RXD,
                MFP108_UART1_TXD,
                MFP_EOC         /*End of configureation*/
        };
        /* configure MFP's */
        mfp_config(mfp_cfg);
        return 0;
}

Signed-off-by: Prafulla Wadaskar <prafulla@marvell.com>

1 files changed, 87 insertions, 0 deletions

diff --git a/drivers/gpio/mvmfp.c b/drivers/gpio/mvmfp.c
new file mode 100644
index 0000000..5646ed4
--- /dev/null
+++ b/drivers/gpio/mvmfp.c
@@ -0,0 +1,87 @@
+/*
+ * (C) Copyright 2010
+ * Marvell Semiconductor <www.marvell.com>
+ * Written-by: Prafulla Wadaskar <prafulla@marvell.com>,
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <mvmfp.h>
+#include <asm/arch/mfp.h>
+#ifdef CONFIG_ARMADA100
+#include <asm/arch/armada100.h>
+#else
+#error Unsupported SoC...
+#endif
+
+/*
+ * mfp_config
+ *
+ * On most of Marvell SoCs (ex. ARMADA100) there is Multi-Funtion-Pin
+ * configuration registers to configure each GPIO/Function pin on the
+ * SoC.
+ *
+ * This function reads the array of values for
+ * MFPR_X registers and programms them into respective
+ * Multi-Function Pin registers.
+ * It supports - Alternate Function Selection programming.
+ *
+ * Whereas,
+ * The Configureation value is constructed using MFP()
+ * array consists of 32bit values as defined in MFP(xx,xx..) macro
+ */
+void mfp_config(u32 *mfp_cfgs)
+{
+	u32 *p_mfpr = NULL;
+	u32 cfg_val, val;
+
+	do {
+		cfg_val = *mfp_cfgs++;
+		/* exit if End of configuration table detected */
+		if (cfg_val == MFP_EOC)
+			break;
+
+		p_mfpr = (u32 *)(MV_MFPR_BASE
+				+ MFP_REG_GET_OFFSET(cfg_val));
+
+		/* Write a mfg register as per configuration */
+		val = 0;
+		if (cfg_val & MFP_AF_FLAG)
+			/* Abstract and program Afternate-Func Selection */
+			val |= cfg_val & MFP_AF_MASK;
+		if (cfg_val & MFP_EDGE_FLAG)
+			/* Abstract and program Edge configuration */
+			val |= cfg_val & MFP_LPM_EDGE_MASK;
+		if (cfg_val & MFP_DRIVE_FLAG)
+			/* Abstract and program Drive configuration */
+			val |= cfg_val & MFP_DRIVE_MASK;
+		if (cfg_val & MFP_PULL_FLAG)
+			/* Abstract and program Pullup/down configuration */
+			val |= cfg_val & MFP_PULL_MASK;
+
+		writel(val, p_mfpr);
+	} while (1);
+	/*
+	 * perform a read-back of any MFPR register to make sure the
+	 * previous writings are finished
+	 */
+	readl(p_mfpr);
+}