Introduce omap_gpmc_read_reg() and omap_gpmc_write_reg() so that the
NAND driver can access the required registers (only those specified in
enum omap_gpmc_reg).
The NAND driver must use these APIs instead of directly accesing the
NAND control registers as they belong to the GPMC controller's register space.
Signed-off-by: Roger Quadros <rogerq@xxxxxx>
---
arch/arm/mach-omap2/gpmc.c | 88 +++++++++++++++++++++++++++++++++++++++++-
include/linux/omap-gpmc-nand.h | 40 +++++++++++++++++++
2 files changed, 127 insertions(+), 1 deletion(-)
create mode 100644 include/linux/omap-gpmc-nand.h
diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
index 2c0c281..92bbada 100644
--- a/arch/arm/mach-omap2/gpmc.c
+++ b/arch/arm/mach-omap2/gpmc.c
@@ -31,7 +31,7 @@
#include <linux/of_device.h>
#include <linux/mtd/nand.h>
#include <linux/pm_runtime.h>
-
+#include <linux/omap-gpmc-nand.h>
#include <linux/platform_data/mtd-nand-omap2.h>
#include <asm/mach-types.h>
@@ -167,10 +167,32 @@ static resource_size_t phys_base, mem_size;
static unsigned gpmc_capability;
static void __iomem *gpmc_base;
+struct gpmc_nand_reg {
+ void __iomem *command;
+ void __iomem *address;
+ void __iomem *data;
+};
+
+static struct gpmc_nand_reg gpmc_nand_reg_map[GPMC_CS_NUM];
+
static struct clk *gpmc_l3_clk;
static irqreturn_t gpmc_handle_irq(int irq, void *dev);
+static void gpmc_fill_nand_reg_map(void)
+{
+ int i;
+
+ for (i = 0; i < gpmc_cs_num; i++) {
+ gpmc_nand_reg_map[i].command = gpmc_base + GPMC_CS0_OFFSET +
+ GPMC_CS_NAND_COMMAND + GPMC_CS_SIZE * i;
+ gpmc_nand_reg_map[i].address = gpmc_base + GPMC_CS0_OFFSET +
+ GPMC_CS_NAND_ADDRESS + GPMC_CS_SIZE * i;
+ gpmc_nand_reg_map[i].data = gpmc_base + GPMC_CS0_OFFSET +
+ GPMC_CS_NAND_DATA + GPMC_CS_SIZE * i;
+ }
+}
+
static void gpmc_write_reg(int idx, u32 val)
{
writel_relaxed(val, gpmc_base + idx);
@@ -1720,6 +1742,7 @@ static int gpmc_probe(struct platform_device *pdev)
return rc;
}
+ gpmc_fill_nand_reg_map();
return 0;
}
@@ -1885,3 +1908,66 @@ void omap3_gpmc_restore_context(void)
}
}
}
+
+/**
+ * omap_gpmc_read_reg - Read the specified GPMC register
+ * @cs: chip select number
+ * @reg: GPMC register id
+ *
+ * Reads the specified register from the appropriate chip select region
+ * and returns the read value.
+ */
+u32 omap_gpmc_read_reg(int cs, enum omap_gpmc_reg reg)
+{
+ if (!gpmc_dev)
+ return 0;
+
+ if (cs >= gpmc_cs_num)
+ return 0;
+
+ switch (reg) {
+ case OMAP_GPMC_STATUS:
+ return gpmc_read_reg(GPMC_STATUS);
+ case OMAP_GPMC_NAND_COMMAND:
+ case OMAP_GPMC_NAND_ADDRESS:
+ return 0; /* command & address regs can't be read */
+ case OMAP_GPMC_NAND_DATA:
+ return readb_relaxed(gpmc_nand_reg_map[cs].data);
+ default:
+ return 0;
+ }
+}
+
+/**
+ * omap_gpmc_write_reg - Write into the specified GPMC register
+ * @cs: chip select number
+ * @reg: GPMC register id
+ * @val: value to write
+ *
+ * Writes the value into the specified register in the appropriate
+ * chip select region.
+ */
+void omap_gpmc_write_reg(int cs, enum omap_gpmc_reg reg, u32 val)
+{
+ if (!gpmc_dev)
+ return;
+
+ if (cs >= gpmc_cs_num)
+ return;
+
+ switch (reg) {
+ case OMAP_GPMC_STATUS:
+ gpmc_write_reg(GPMC_STATUS, val);
+ case OMAP_GPMC_NAND_COMMAND:
+ writeb_relaxed(val, gpmc_nand_reg_map[cs].command);
+ break;
+ case OMAP_GPMC_NAND_ADDRESS:
+ writeb_relaxed(val, gpmc_nand_reg_map[cs].address);
+ break;
+ case OMAP_GPMC_NAND_DATA:
+ writeb_relaxed(val, gpmc_nand_reg_map[cs].data);
+ break;
+ default:
+ break;
+ }
+}
diff --git a/include/linux/omap-gpmc-nand.h b/include/linux/omap-gpmc-nand.h
new file mode 100644
index 0000000..dcb2abe
--- /dev/null
+++ b/include/linux/omap-gpmc-nand.h
@@ -0,0 +1,40 @@
+/*
+ * OMAP NAND to GPMC custom API interface
+ *
+ * Copyright (C) 2014 Texas Instruments, Inc. - http://www.ti.com
+ * Roger Quadros <rogerq@xxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ */
+
+#ifndef _OMAP_GPMC_NAND_H_
+#define _OMAP_GPMC_NAND_H_
+
+/**
+ * Registers that need to be accessed by the OMAP NAND driver
+ */
+
+enum omap_gpmc_reg {
+ OMAP_GPMC_STATUS,
+ OMAP_GPMC_NAND_COMMAND,
+ OMAP_GPMC_NAND_ADDRESS,
+ OMAP_GPMC_NAND_DATA,
+};
+
+#ifdef CONFIG_ARCH_OMAP2PLUS
+u32 omap_gpmc_read_reg(int cs, enum omap_gpmc_reg reg);
+void omap_gpmc_write_reg(int cs, enum omap_gpmc_reg reg, u32 val);
+#else
+static inline u32 omap_gpmc_read_reg(int cs, enum omap_gpmc_reg reg)
+{
+ return 0;
+}
+
+static inline void omap_gpmc_write_reg(int cs, enum omap_gpmc_reg reg, u32 val)
+{
+}
+#endif
+
+#endif /* _GPMC_OMAP_H_ */
--
1.8.3.2
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