Patchwork [v4,2/2] davinci: Platform support for OMAP-L137/AM17x NOR flash driver

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Submitter Savinay Dharmappa
Date Nov. 30, 2010, 10:02 a.m.
Message ID <1291111361-25848-1-git-send-email-savinay.dharmappa@ti.com>
Download mbox | patch
Permalink /patch/73589/
State New
Headers show

Comments

Savinay Dharmappa - Nov. 30, 2010, 10:02 a.m.
From: Aleksey Makarov <amakarov@ru.mvista.com>

Adds platform support for OMAP-L137/AM17x NOR flash driver.

Also, configures chip select 3 to control NOR flash's upper
address lines.

Signed-off-by: Aleksey Makarov <amakarov@ru.mvista.com>
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Savinay Dharmappa <savinay.dharmappa@ti.com>
---
Since v3:
Addressed comments from Sergei Shtylyov at [1].

[1]http://linux.davincidsp.com/pipermail/davinci-linux-open-source/2010-November/021105.html

 arch/arm/mach-davinci/Kconfig           |    8 +
 arch/arm/mach-davinci/board-da830-evm.c |  217 +++++++++++++++++++++++++++++++
 2 files changed, 225 insertions(+), 0 deletions(-)

Patch

diff --git a/arch/arm/mach-davinci/Kconfig b/arch/arm/mach-davinci/Kconfig
index 84066e8..72d4fd0 100644
--- a/arch/arm/mach-davinci/Kconfig
+++ b/arch/arm/mach-davinci/Kconfig
@@ -142,6 +142,14 @@  config DA830_UI_NAND
 	help
 	  Say Y here to use the NAND flash. Do not forget to setup
 	  the switch correctly.
+
+config DA830_UI_NOR
+        bool "NOR flash"
+        help
+          Configure this option to specify the that AEMIF CE2/CE3 will be used to
+          communicate to the NOR flash. Do not forget to setup the switch SW1
+          on UI card correctly.
+
 endchoice
 
 config MACH_DAVINCI_DA850_EVM
diff --git a/arch/arm/mach-davinci/board-da830-evm.c b/arch/arm/mach-davinci/board-da830-evm.c
index b52a3a1..93daf52 100644
--- a/arch/arm/mach-davinci/board-da830-evm.c
+++ b/arch/arm/mach-davinci/board-da830-evm.c
@@ -20,6 +20,8 @@ 
 #include <linux/i2c/at24.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
+#include <linux/mtd/latch-addr-flash.h>
+#include <linux/clk.h>
 
 #include <asm/mach-types.h>
 #include <asm/mach/arch.h>
@@ -429,6 +431,219 @@  static inline void da830_evm_init_nand(int mux_mode)
 static inline void da830_evm_init_nand(int mux_mode) { }
 #endif
 
+#ifdef CONFIG_DA830_UI_NOR
+/*
+ * Number of lines going to the NOR flash that are used as
+ * AEMIF address lines B_EMIF_BA0-B_EMIF_A12 on CS2.
+ */
+#define NOR_WINDOW_SIZE_LOG2     15
+#define NOR_WINDOW_SIZE         (1 << NOR_WINDOW_SIZE_LOG2)
+
+static struct {
+	struct clk *clk;
+	void __iomem *latch_addr;
+	void __iomem *aemif_addr;
+} da830_evm_nor;
+
+static struct davinci_aemif_timing da830_evm_norflash_timing = {
+	.wsetup		= 0,
+	.wstrobe	= 40,
+	.whold		= 0,
+	.rsetup		= 0,
+	.rstrobe	= 130,
+	.rhold		= 0,
+	.ta		= 20,
+};
+
+static void da830_evm_nor_set_window(unsigned long offset, void *data)
+{
+	/*
+	 * CS2 and CS3 lines are used to address NOR flash. Address lines
+	 * A0-A14 from NOR flash are connected to AEMIF address lines
+	 * B_EMIF_BA0-B_EMIF_A12 on CS2. Address lines A15-A23 of the NOR
+	 * flash are latched from AEMIF address lines B_EMIF_A0-B_EMIF_A6
+	 * on CS3. The offset argument received by this function is the offset
+	 * within NOR flash. Upper address is obtained  by shifting the offset
+	 * by the number of CS2 address lines used (13) and masking it with
+	 * complement of 3 (2 address lines used to address banks) and adding
+	 * the resultant offset value to CS3 base address. Writing to this
+	 * address will latch the upper address lines.
+	 */
+	writeb(0x0, da830_evm_nor.latch_addr +
+		(~3UL & (offset >> (NOR_WINDOW_SIZE_LOG2 - 2))));
+}
+
+static void da830_evm_nor_done(void *data)
+{
+	clk_disable(da830_evm_nor.clk);
+	clk_put(da830_evm_nor.clk);
+	iounmap(da830_evm_nor.latch_addr);
+	release_mem_region(DA8XX_AEMIF_CS3_BASE, PAGE_SIZE);
+	iounmap(da830_evm_nor.aemif_addr);
+	release_mem_region(DA8XX_AEMIF_CTL_BASE, SZ_32K);
+}
+
+static int da830_evm_nor_init(void *data, int cs)
+{
+	struct resource *res = NULL;
+
+	/* Turn on AEMIF clocks */
+	da830_evm_nor.clk = clk_get(NULL, "aemif");
+	if (IS_ERR(da830_evm_nor.clk)) {
+		pr_err("%s: could not get AEMIF clock\n", __func__);
+		da830_evm_nor.clk = NULL;
+		return -ENODEV;
+	}
+	clk_enable(da830_evm_nor.clk);
+
+	res = request_mem_region(DA8XX_AEMIF_CTL_BASE, SZ_32K, "AEMIF control");
+	if (res == NULL) {
+		pr_err("%s: could not request AEMIF control region\n",
+			__func__);
+		goto err_clk;
+	}
+
+	da830_evm_nor.aemif_addr = ioremap_nocache(DA8XX_AEMIF_CTL_BASE,
+						   SZ_32K);
+	if (da830_evm_nor.aemif_addr == NULL) {
+		pr_err("%s: could not remap AEMIF control region\n", __func__);
+		goto err_aemif_region;
+	}
+
+	/* Setup AEMIF -- timings, etc. */
+
+	/* Set maximum wait cycles */
+	davinci_aemif_setup_timing(&da830_evm_norflash_timing,
+						da830_evm_nor.aemif_addr, cs);
+
+	davinci_aemif_setup_timing(&da830_evm_norflash_timing,
+					da830_evm_nor.aemif_addr, cs + 1);
+
+	/* Setup the window to access the latch */
+	res = request_mem_region(DA8XX_AEMIF_CS3_BASE, PAGE_SIZE,
+				"DA830 UI NOR address latch");
+	if (res == NULL) {
+		pr_err("%s: could not request address latch region\n",
+			__func__);
+		goto err_aemif_ioremap;
+	}
+
+	da830_evm_nor.latch_addr =
+		ioremap_nocache(DA8XX_AEMIF_CS3_BASE, PAGE_SIZE);
+	if (da830_evm_nor.latch_addr == NULL) {
+		pr_err("%s: could not remap address latch region\n", __func__);
+		goto err_latch_region;
+	}
+	return 0;
+
+err_latch_region:
+	release_mem_region(DA8XX_AEMIF_CS3_BASE, PAGE_SIZE);
+
+err_aemif_ioremap:
+	iounmap(da830_evm_nor.aemif_addr);
+
+err_aemif_region:
+	release_mem_region(DA8XX_AEMIF_CTL_BASE, SZ_32K);
+
+err_clk:
+	clk_disable(da830_evm_nor.clk);
+	clk_put(da830_evm_nor.clk);
+
+	return -ENOMEM;
+}
+
+static struct mtd_partition da830_evm_nor_partitions[] = {
+	/* bootloader (U-Boot, etc) in first 2 sectors */
+	[0] = {
+		.name           = "bootloader",
+		.offset		= 0,
+		.size           = SZ_128K,
+		.mask_flags     = MTD_WRITEABLE, /* force read-only */
+	},
+	/* bootloader parameters in the next 1 sector */
+	[1] = {
+		.name           = "params",
+		.offset         = MTDPART_OFS_APPEND,
+		.size           = SZ_64K,
+	},
+	/* kernel */
+	[2] = {
+		.name           = "kernel",
+		.offset         = MTDPART_OFS_APPEND,
+		.size           = SZ_2M,
+	},
+	/* file system */
+	[3] = {
+		.name           = "filesystem",
+		.offset         = MTDPART_OFS_APPEND,
+		.size           = MTDPART_SIZ_FULL,
+	}
+};
+
+static struct latch_addr_flash_data da830_evm_nor_pdata = {
+	.width          = 1,
+	.size           = SZ_4M,
+	.init           = da830_evm_nor_init,
+	.done           = da830_evm_nor_done,
+	.set_window     = da830_evm_nor_set_window,
+	.nr_parts       = ARRAY_SIZE(da830_evm_nor_partitions),
+	.parts          = da830_evm_nor_partitions,
+};
+
+static struct resource da830_evm_nor_resource[] = {
+	[0] = {
+		.start  = DA8XX_AEMIF_CS2_BASE,
+		.end    = DA8XX_AEMIF_CS2_BASE + NOR_WINDOW_SIZE - 1,
+		.flags  = IORESOURCE_MEM,
+	},
+	[1] = {
+		.start  = DA8XX_AEMIF_CS3_BASE,
+		.end    = DA8XX_AEMIF_CS3_BASE + PAGE_SIZE - 1,
+		.flags  = IORESOURCE_MEM,
+	},
+	[2] = {
+		.start  = DA8XX_AEMIF_CTL_BASE,
+		.end    = DA8XX_AEMIF_CTL_BASE + SZ_32K - 1,
+		.flags  = IORESOURCE_MEM,
+	}
+};
+
+static struct platform_device da830_evm_nor_device = {
+	.name           = "latch-addr-flash",
+	.id             = 0,
+	.dev            = {
+		.platform_data  = &da830_evm_nor_pdata,
+	},
+	.num_resources  = ARRAY_SIZE(da830_evm_nor_resource),
+	.resource       = da830_evm_nor_resource,
+};
+
+static inline void da830_evm_init_nor(int mux_mode)
+{
+	int ret;
+
+	if (HAS_MMC) {
+		pr_warning("WARNING: both MMC/SD and NOR are "
+			   "enabled, but they share AEMIF pins.\n"
+			   "\tDisable MMC/SD for NOR support.\n");
+		return;
+	}
+
+	ret = davinci_cfg_reg_list(da830_evm_emif25_pins);
+	if (ret)
+		pr_warning("da830_evm_init: EMIF 2.5 mux setup failed: %d\n",
+			  ret);
+
+	ret = platform_device_register(&da830_evm_nor_device);
+	if (ret)
+		pr_warning("da830_evm_init: NOR device not registered.\n");
+
+	gpio_direction_output(mux_mode, 1);
+}
+#else
+static inline void da830_evm_init_nor(int mux_mode) { }
+#endif  /* CONFIG_DA830_UI_NOR */
+
 #ifdef CONFIG_DA830_UI_LCD
 static inline void da830_evm_init_lcdc(int mux_mode)
 {
@@ -469,6 +684,8 @@  static int __init da830_evm_ui_expander_setup(struct i2c_client *client,
 
 	da830_evm_init_nand(gpio + 6);
 
+	da830_evm_init_nor(gpio + 6);
+
 	return 0;
 }