@@ -1,5 +1,5 @@
# Common support
-obj-y := clock.o devices.o gpio.o icoll.o iomux.o system.o timer.o
+obj-y := clock.o devices.o gpio.o icoll.o iomux.o ocotp.o system.o timer.o
obj-$(CONFIG_SOC_IMX23) += clock-mx23.o mm-mx23.o
obj-$(CONFIG_SOC_IMX28) += clock-mx28.o mm-mx28.o
@@ -13,6 +13,7 @@
struct clk;
+extern int mxs_read_ocotp(int offset, int count, u32 *values);
extern int mxs_reset_block(void __iomem *);
extern void mxs_timer_init(struct clk *, int);
new file mode 100644
@@ -0,0 +1,79 @@
+/*
+ * Copyright 2010 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * 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.
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+
+#include <mach/mxs.h>
+
+#define BM_OCOTP_CTRL_BUSY (1 << 8)
+#define BM_OCOTP_CTRL_ERROR (1 << 9)
+#define BM_OCOTP_CTRL_RD_BANK_OPEN (1 << 12)
+
+static DEFINE_MUTEX(ocotp_mutex);
+
+int mxs_read_ocotp(unsigned offset, size_t count, u32 *values)
+{
+ void __iomem *ocotp_base = MXS_IO_ADDRESS(MXS_OCOTP_BASE_ADDR);
+ int timeout = 0x400;
+ size_t i;
+
+ mutex_lock(&ocotp_mutex);
+
+ /*
+ * clk_enable(hbus_clk) for ocotp can be skipped
+ * as it must be on when system is running.
+ */
+
+ /* try to clear ERROR bit */
+ __mxs_clrl(BM_OCOTP_CTRL_ERROR, ocotp_base);
+
+ /* check both BUSY and ERROR cleared */
+ while ((__raw_readl(ocotp_base) &
+ (BM_OCOTP_CTRL_BUSY | BM_OCOTP_CTRL_ERROR)) && --timeout)
+ /* nothing */;
+
+ if (unlikely(!timeout))
+ goto error_unlock;
+
+ /* open OCOTP banks for read */
+ __mxs_setl(BM_OCOTP_CTRL_RD_BANK_OPEN, ocotp_base);
+
+ /* approximately wait 32 hclk cycles */
+ udelay(1);
+
+ /* poll BUSY bit becoming cleared */
+ timeout = 0x400;
+ while ((__raw_readl(ocotp_base) & BM_OCOTP_CTRL_BUSY) && --timeout)
+ /* nothing */;
+
+ if (unlikely(!timeout))
+ goto error_unlock;
+
+ for (i = 0; i < count; i++, offset += 4)
+ *values++ = __raw_readl(ocotp_base + offset);
+
+ /* close banks for power saving */
+ __mxs_clrl(BM_OCOTP_CTRL_RD_BANK_OPEN, ocotp_base);
+
+ mutex_unlock(&ocotp_mutex);
+
+ return 0;
+
+error_unlock:
+ mutex_unlock(&ocotp_mutex);
+ pr_err("%s: timeout in reading OCOTP\n", __func__);
+ return -ETIMEDOUT;
+}
Signed-off-by: Shawn Guo <shawn.guo@freescale.com> --- Changes for v2: - Add mutex locking for mxs_read_ocotp() - Use type size_t for count and i - Add comment for clk_enable/disable skipping - Add ERROR bit clearing and polling step arch/arm/mach-mxs/Makefile | 2 +- arch/arm/mach-mxs/include/mach/common.h | 1 + arch/arm/mach-mxs/ocotp.c | 79 +++++++++++++++++++++++++++++++ 3 files changed, 81 insertions(+), 1 deletions(-) create mode 100644 arch/arm/mach-mxs/ocotp.c