[PATCH] arm,davinci: configure davinci aemif chipselects through OF

Heiko Schocher hs at denx.de
Sun Dec 4 20:41:19 EST 2011


Signed-off-by: Heiko Schocher <hs at denx.de>
Cc: davinci-linux-open-source at linux.davincidsp.com
Cc: devicetree-discuss at lists.ozlabs.org
Cc: linux-arm-kernel at lists.infradead.org
Cc: grant.likely at secretlab.ca
Cc: Sekhar Nori <nsekhar at ti.com>
Cc: Kevin Hilman <khilman at ti.com>
Cc: Wolfgang Denk <wd at denx.de>
---
 .../devicetree/bindings/arm/davinci/aemif.txt      |   85 ++++++++++++++++
 arch/arm/mach-davinci/aemif.c                      |  105 +++++++++++++++++++-
 arch/arm/mach-davinci/include/mach/aemif.h         |    1 +
 3 files changed, 190 insertions(+), 1 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/arm/davinci/aemif.txt

diff --git a/Documentation/devicetree/bindings/arm/davinci/aemif.txt b/Documentation/devicetree/bindings/arm/davinci/aemif.txt
new file mode 100644
index 0000000..c9ed551
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/davinci/aemif.txt
@@ -0,0 +1,85 @@
+* Texas Instruments Davinci AEMIF
+
+This file provides information, what the device node for the
+davinci aemifa interface contain.
+
+Required properties:
+- compatible: "ti,davinci-emifa";
+- #address-cells : Should be either two or three.  The first cell is the
+                   chipselect number, and the remaining cells are the
+                   offset into the chipselect.
+- #size-cells : Either one or two, depending on how large each chipselect
+                can be.
+- ranges : Each range corresponds to a single chipselect, and cover
+           the entire access window as configured.
+
+Optional properties:
+- none
+
+Optional subnodes:
+- Chipselect setup:
+  - Required properties:
+	- compatible: "ti,davinci-cs";
+	- #address-cells = <1>;
+	- #size-cells = <1>;
+
+    Timing setup, all timings in nanoseconds
+	- cs:		chipselect (value 2,3,4 or 5)
+	- asize:	Asynchronous Data Bus Width.
+			value:
+			0: 8 bit
+			1: 16 bit
+	- ta:		Minimum Turn-Around time.
+	- rhold:	Read hold width
+	- rstrobe:	Read strobe width
+	- rsetup:	Read setup width
+	- whold:	Write hold width
+	- wstrobe:	Write strobe width
+	- wsetup:	Write setup width
+	- ew:		Extend Wait bit
+			value:
+			0: Extended wait cycles disabled.
+			1: Extended wait cycles enabled.
+	-ss:		Select Strobe bit.
+			value:
+			0: Normal Mode enabled.
+			1: Select Strobe Mode enabled.
+- CFI driver:
+  see: Documentation/devicetree/bindings/mtd/mtd-physmap.txt
+
+Example (enbw_cmc board):
+	aemif at 60000000 {
+		compatible = "ti,davinci-emifa";
+		#address-cells = <2>;
+		#size-cells = <1>;
+		reg = <0x68000000 0x80000>;
+		ranges = <2 0 0x60000000 0x02000000
+			  3 0 0x62000000 0x02000000
+			  4 0 0x64000000 0x02000000
+			  5 0 0x66000000 0x02000000>;
+		cs2 at 0x60000000 {
+			compatible = "ti,davinci-cs";
+			#address-cells = <1>;
+			#size-cells = <1>;
+			/* all timings in nanoseconds */
+			cs = <2>;
+			asize = <1>;
+			ta = <0>;
+			rhold = <7>;
+			rstrobe = <42>;
+			rsetup = <14>;
+			whold = <7>;
+			wstrobe = <42>;
+			wsetup = <14>;
+			ew = <0>;
+			ss = <0>;
+		};
+		flash at 2,0 {
+			compatible = "cfi-flash";
+			reg = <2 0x0 0x400000>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+			bank-width = <2>;
+			device-width = <2>;
+		};
+	};
diff --git a/arch/arm/mach-davinci/aemif.c b/arch/arm/mach-davinci/aemif.c
index 1ce70a9..12c559f 100644
--- a/arch/arm/mach-davinci/aemif.c
+++ b/arch/arm/mach-davinci/aemif.c
@@ -13,12 +13,14 @@
 #include <linux/err.h>
 #include <linux/clk.h>
 #include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/time.h>
 
 #include <mach/aemif.h>
 
 /* Timing value configuration */
-
+#define ASIZE(x)	(x)
 #define TA(x)		((x) << 2)
 #define RHOLD(x)	((x) << 4)
 #define RSTROBE(x)	((x) << 7)
@@ -26,7 +28,10 @@
 #define WHOLD(x)	((x) << 17)
 #define WSTROBE(x)	((x) << 20)
 #define WSETUP(x)	((x) << 26)
+#define EW(x)		((x) << 30)
+#define SS(x)		((x) << 31)
 
+#define ASIZE_MAX	0x1
 #define TA_MAX		0x3
 #define RHOLD_MAX	0x7
 #define RSTROBE_MAX	0x3f
@@ -34,6 +39,8 @@
 #define WHOLD_MAX	0x7
 #define WSTROBE_MAX	0x3f
 #define WSETUP_MAX	0xf
+#define EW_MAX		0x1
+#define SS_MAX		0x1
 
 #define TIMING_MASK	(TA(TA_MAX) | \
 				RHOLD(RHOLD_MAX) | \
@@ -131,3 +138,99 @@ int davinci_aemif_setup_timing(struct davinci_aemif_timing *t,
 	return 0;
 }
 EXPORT_SYMBOL(davinci_aemif_setup_timing);
+
+#if defined(CONFIG_OF)
+static int dv_get_value(struct device_node *np, const char *name)
+{
+	const u32 *data;
+	int len;
+
+	data = of_get_property(np, name, &len);
+	if (data)
+		return be32_to_cpu(readl(data));
+
+	return -EINVAL;
+}
+
+static int davinci_aemif_setup_timing_of_one(struct device_node *np,
+		void __iomem *base)
+{
+	unsigned val;
+	int asize, ta, rhold, rstrobe, rsetup, whold, wstrobe, wsetup;
+	int ew, ss;
+	int cs;
+	unsigned offset;
+	struct clk *aemif_clk;
+	unsigned long clkrate;
+
+	aemif_clk = clk_get(NULL, "aemif");
+	if (IS_ERR(aemif_clk))
+		return PTR_ERR(aemif_clk);
+
+	clkrate = clk_get_rate(aemif_clk);
+
+	clkrate /= 1000;	/* turn clock into kHz for ease of use */
+
+	cs = dv_get_value(np, "cs");
+	if (cs < 2)
+		return -EINVAL;
+
+	offset = A1CR_OFFSET + (cs - 2) * 4;
+	asize	= dv_get_value(np, "asize");
+	ta	= aemif_calc_rate(dv_get_value(np, "ta"), clkrate, TA_MAX);
+	rhold	= aemif_calc_rate(dv_get_value(np, "rhold"), clkrate,
+			RHOLD_MAX);
+	rstrobe	= aemif_calc_rate(dv_get_value(np, "rstrobe"), clkrate,
+			RSTROBE_MAX);
+	rsetup	= aemif_calc_rate(dv_get_value(np, "rsetup"), clkrate,
+			RSETUP_MAX);
+	whold	= aemif_calc_rate(dv_get_value(np, "whold"), clkrate,
+			WHOLD_MAX);
+	wstrobe	= aemif_calc_rate(dv_get_value(np, "wstrobe"), clkrate,
+			WSTROBE_MAX);
+	wsetup	= aemif_calc_rate(dv_get_value(np, "wsetup"), clkrate,
+			WSETUP_MAX);
+	ew	= dv_get_value(np, "ew");
+	ss	= dv_get_value(np, "ss");
+
+	if (asize < 0 || ta < 0 || rhold < 0 || rstrobe < 0 || rsetup < 0 ||
+			whold < 0 || wstrobe < 0 || wsetup < 0 || ew < 0 ||
+			ss < 0) {
+		pr_err("%s: cannot get suitable timings\n", __func__);
+		return -EINVAL;
+	}
+
+	val = ASIZE(asize) | TA(ta) | RHOLD(rhold) | RSTROBE(rstrobe) |
+		RSETUP(rsetup) | WHOLD(whold) | WSTROBE(wstrobe) |
+		WSETUP(wsetup) | EW(ew) | SS(ss);
+
+	__raw_writel(val, base + offset);
+
+	return 0;
+}
+
+int davinci_aemif_setup_timing_of(void)
+{
+	struct device_node *np = NULL;
+	void __iomem *base;
+
+	np =  of_find_compatible_node(NULL, NULL, "ti,davinci-emifa");
+	if (!np) {
+		pr_warning("%s: ti,davinci-emifa not found\n", __func__);
+		return 0;
+	}
+
+	base = of_iomap(np, 0);
+	for_each_compatible_node(np, NULL, "ti,davinci-cs")
+		davinci_aemif_setup_timing_of_one(np, base);
+
+	iounmap(base);
+	return 0;
+}
+#else
+int davinci_aemif_setup_timing_of(void)
+{
+	return 0;
+}
+#endif
+EXPORT_SYMBOL(davinci_aemif_setup_timing_of);
diff --git a/arch/arm/mach-davinci/include/mach/aemif.h b/arch/arm/mach-davinci/include/mach/aemif.h
index 05b2934..1538565 100644
--- a/arch/arm/mach-davinci/include/mach/aemif.h
+++ b/arch/arm/mach-davinci/include/mach/aemif.h
@@ -33,4 +33,5 @@ struct davinci_aemif_timing {
 
 int davinci_aemif_setup_timing(struct davinci_aemif_timing *t,
 					void __iomem *base, unsigned cs);
+int davinci_aemif_setup_timing_of(void);
 #endif
-- 
1.7.6.4



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