mtd: nand: denali: handle timing parameters by setup_data_interface()

Handling timing parameters in a driver's own way should be avoided
because it duplicates efforts of drivers/mtd/nand/nand_timings.c
Besides, this driver hard-codes Intel specific parameters such as
CLK_X=5, CLK_MULTI=4.  Taking a certain device (Samsung K9WAG08U1A)
into account by get_samsung_nand_para() is weird as well.

Now, the core framework provides .setup_data_interface() hook, which
handles timing parameters in a generic manner.

While I am working on this, I found even more issues in the current
code, so fixed the following as well:

- In recent IP versions, WE_2_RE and TWHR2 share the same register.
  Likewise for ADDR_2_DATA and TCWAW, CS_SETUP_CNT and TWB.  When
  updating one, the other must be masked.  Otherwise, the other will
  be set to 0, then timing settings will be broken.

- The recent IP release expanded the ADDR_2_DATA to 7-bit wide.
  This register is related to tADL.  As commit 74a332e7 ("mtd:
  nand: timings: Fix tADL_min for ONFI 4.0 chips") addressed, the
  ONFi 4.0 increased the minimum of tADL to 400 nsec.  This may not
  fit in the 6-bit ADDR_2_DATA in older versions.  Check the IP
  revision and handle this correctly, otherwise the register value
  would wrap around.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

drivers/mtd/nand/denali.h

@@ -72,11 +72,14 @@
 #define GLOBAL_INT_ENABLE			0xf0
 #define     GLOBAL_INT_EN_FLAG				BIT(0)
 
-#define WE_2_RE					0x100
-#define     WE_2_RE__VALUE				GENMASK(5, 0)
+#define TWHR2_AND_WE_2_RE			0x100
+#define     TWHR2_AND_WE_2_RE__WE_2_RE			GENMASK(5, 0)
+#define     TWHR2_AND_WE_2_RE__TWHR2			GENMASK(13, 8)
 
-#define ADDR_2_DATA				0x110
-#define     ADDR_2_DATA__VALUE				GENMASK(5, 0)
+#define TCWAW_AND_ADDR_2_DATA			0x110
+/* The width of ADDR_2_DATA is 6 bit for old IP, 7 bit for new IP */
+#define     TCWAW_AND_ADDR_2_DATA__ADDR_2_DATA		GENMASK(6, 0)
+#define     TCWAW_AND_ADDR_2_DATA__TCWAW		GENMASK(13, 8)
 
 #define RE_2_WE					0x120
 #define     RE_2_WE__VALUE				GENMASK(5, 0)
@@ -128,6 +131,7 @@
 
 #define CS_SETUP_CNT				0x220
 #define     CS_SETUP_CNT__VALUE				GENMASK(4, 0)
+#define     CS_SETUP_CNT__TWB				GENMASK(17, 12)
 
 #define SPARE_AREA_SKIP_BYTES			0x230
 #define     SPARE_AREA_SKIP_BYTES__VALUE		GENMASK(5, 0)
@@ -294,16 +298,8 @@
 #define     CHNL_ACTIVE__CHANNEL2			BIT(2)
 #define     CHNL_ACTIVE__CHANNEL3			BIT(3)
 
-#define FAIL 1                  /*failed flag*/
 #define PASS 0                  /*success flag*/
 
-#define CLK_X  5
-#define CLK_MULTI 4
-
-#define ONFI_BLOOM_TIME         1
-#define MODE5_WORKAROUND        0
-
-
 #define MODE_00    0x00000000
 #define MODE_01    0x04000000
 #define MODE_10    0x08000000
@@ -316,14 +312,10 @@ struct nand_buf {
 	dma_addr_t dma_buf;
 };
 
-#define INTEL_CE4100	1
-#define INTEL_MRST	2
-#define DT		3
-
 struct denali_nand_info {
 	struct nand_chip nand;
+	unsigned long clk_x_rate;	/* bus interface clock rate */
 	int flash_bank; /* currently selected chip */
-	int platform;
 	struct nand_buf buf;
 	struct device *dev;
 	int page;

drivers/mtd/nand/denali_dt.c

@@ -96,7 +96,6 @@ static int denali_dt_probe(struct platform_device *pdev)
 		denali->ecc_caps = data->ecc_caps;
 	}
 
-	denali->platform = DT;
 	denali->dev = &pdev->dev;
 	denali->irq = platform_get_irq(pdev, 0);
 	if (denali->irq < 0) {
@@ -121,6 +120,8 @@ static int denali_dt_probe(struct platform_device *pdev)
 	}
 	clk_prepare_enable(dt->clk);
 
+	denali->clk_x_rate = clk_get_rate(dt->clk);
+
 	ret = denali_init(denali);
 	if (ret)
 		goto out_disable_clk;

drivers/mtd/nand/denali_pci.c

@@ -19,6 +19,9 @@
 
 #define DENALI_NAND_NAME    "denali-nand-pci"
 
+#define INTEL_CE4100	1
+#define INTEL_MRST	2
+
 /* List of platforms this NAND controller has be integrated into */
 static const struct pci_device_id denali_pci_ids[] = {
 	{ PCI_VDEVICE(INTEL, 0x0701), INTEL_CE4100 },
@@ -47,13 +50,11 @@ static int denali_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	}
 
 	if (id->driver_data == INTEL_CE4100) {
-		denali->platform = INTEL_CE4100;
 		mem_base = pci_resource_start(dev, 0);
 		mem_len = pci_resource_len(dev, 1);
 		csr_base = pci_resource_start(dev, 1);
 		csr_len = pci_resource_len(dev, 1);
 	} else {
-		denali->platform = INTEL_MRST;
 		csr_base = pci_resource_start(dev, 0);
 		csr_len = pci_resource_len(dev, 0);
 		mem_base = pci_resource_start(dev, 1);
@@ -69,6 +70,7 @@ static int denali_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	denali->irq = dev->irq;
 	denali->ecc_caps = &denali_pci_ecc_caps;
 	denali->nand.ecc.options |= NAND_ECC_MAXIMIZE;
+	denali->clk_x_rate = 200000000;		/* 200 MHz */
 
 	ret = pci_request_regions(dev, DENALI_NAND_NAME);
 	if (ret) {