ARM: davinci: aemif: get rid of davinci-nand driver dependency on aemif

The problem that the set timings code contains the call of Davinci
platform function davinci_aemif_setup_timing() which is not
accessible if kernel is built for another platform like Keystone.

The Keysone platform is going to use TI AEMIF driver.
If TI AEMIF is used we don't need to set timings and bus width.
It is done by AEMIF driver.

To get rid of davinci-nand driver dependency on aemif platform code
we moved aemif code to davinci platform.

The platform AEMIF code (aemif.c) has to be removed once Davinci
will be converted to DT and use ti-aemif.c driver.

Acked-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>
[nsekhar@ti.com: fixed checkpatch error and a build breakage due to
		 missing include, rebased onto l2-mtd/master]
Signed-off-by: Sekhar Nori <nsekhar@ti.com>

1 files changed, 96 insertions, 11 deletions

diff --git a/arch/arm/mach-davinci/aemif.c b/arch/arm/mach-davinci/aemif.c
index f091a9010c2f..ff8b7e76b6e9 100644
--- a/arch/arm/mach-davinci/aemif.c
+++ b/arch/arm/mach-davinci/aemif.c
@@ -16,6 +16,7 @@
 #include <linux/time.h>
 
 #include <linux/platform_data/mtd-davinci-aemif.h>
+#include <linux/platform_data/mtd-davinci.h>
 
 /* Timing value configuration */
 
@@ -43,6 +44,17 @@
 				WSTROBE(WSTROBE_MAX) | \
 				WSETUP(WSETUP_MAX))
 
+static inline unsigned int davinci_aemif_readl(void __iomem *base, int offset)
+{
+	return readl_relaxed(base + offset);
+}
+
+static inline void davinci_aemif_writel(void __iomem *base,
+					int offset, unsigned long value)
+{
+	writel_relaxed(value, base + offset);
+}
+
 /*
  * aemif_calc_rate - calculate timing data.
  * @wanted: The cycle time needed in nanoseconds.
@@ -76,6 +88,7 @@ static int aemif_calc_rate(int wanted, unsigned long clk, int max)
  * @t: timing values to be progammed
  * @base: The virtual base address of the AEMIF interface
  * @cs: chip-select to program the timing values for
+ * @clkrate: the AEMIF clkrate
  *
  * This function programs the given timing values (in real clock) into the
  * AEMIF registers taking the AEMIF clock into account.
@@ -86,24 +99,17 @@ static int aemif_calc_rate(int wanted, unsigned long clk, int max)
  *
  * Returns 0 on success, else negative errno.
  */
-int davinci_aemif_setup_timing(struct davinci_aemif_timing *t,
-					void __iomem *base, unsigned cs)
+static int davinci_aemif_setup_timing(struct davinci_aemif_timing *t,
+					void __iomem *base, unsigned cs,
+					unsigned long clkrate)
 {
 	unsigned set, val;
 	int ta, rhold, rstrobe, rsetup, whold, wstrobe, wsetup;
 	unsigned offset = A1CR_OFFSET + cs * 4;
-	struct clk *aemif_clk;
-	unsigned long clkrate;
 
 	if (!t)
 		return 0;	/* Nothing to do */
 
-	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 */
 
 	ta	= aemif_calc_rate(t->ta, clkrate, TA_MAX);
@@ -130,4 +136,83 @@ int davinci_aemif_setup_timing(struct davinci_aemif_timing *t,
 
 	return 0;
 }
-EXPORT_SYMBOL(davinci_aemif_setup_timing);
+
+/**
+ * davinci_aemif_setup - setup AEMIF interface by davinci_nand_pdata
+ * @pdev - link to platform device to setup settings for
+ *
+ * This function does not use any locking while programming the AEMIF
+ * because it is expected that there is only one user of a given
+ * chip-select.
+ *
+ * Returns 0 on success, else negative errno.
+ */
+int davinci_aemif_setup(struct platform_device *pdev)
+{
+	struct davinci_nand_pdata *pdata = dev_get_platdata(&pdev->dev);
+	uint32_t val;
+	unsigned long clkrate;
+	struct resource	*res;
+	void __iomem *base;
+	struct clk *clk;
+	int ret = 0;
+
+	clk = clk_get(&pdev->dev, "aemif");
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		dev_dbg(&pdev->dev, "unable to get AEMIF clock, err %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(clk);
+	if (ret < 0) {
+		dev_dbg(&pdev->dev, "unable to enable AEMIF clock, err %d\n",
+			ret);
+		goto err_put;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res) {
+		dev_err(&pdev->dev, "cannot get IORESOURCE_MEM\n");
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	base = ioremap(res->start, resource_size(res));
+	if (!base) {
+		dev_err(&pdev->dev, "ioremap failed for resource %pR\n", res);
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	/*
+	 * Setup Async configuration register in case we did not boot
+	 * from NAND and so bootloader did not bother to set it up.
+	 */
+	val = davinci_aemif_readl(base, A1CR_OFFSET + pdev->id * 4);
+	/*
+	 * Extended Wait is not valid and Select Strobe mode is not
+	 * used
+	 */
+	val &= ~(ACR_ASIZE_MASK | ACR_EW_MASK | ACR_SS_MASK);
+	if (pdata->options & NAND_BUSWIDTH_16)
+		val |= 0x1;
+
+	davinci_aemif_writel(base, A1CR_OFFSET + pdev->id * 4, val);
+
+	clkrate = clk_get_rate(clk);
+
+	if (pdata->timing)
+		ret = davinci_aemif_setup_timing(pdata->timing, base, pdev->id,
+						 clkrate);
+
+	if (ret < 0)
+		dev_dbg(&pdev->dev, "NAND timing values setup fail\n");
+
+	iounmap(base);
+err:
+	clk_disable_unprepare(clk);
+err_put:
+	clk_put(clk);
+	return ret;
+}