mtd: gpmi: add gpmi_devdata{} to simplify the code

More and more chips use the GPMI controller, but these chips may use different
version of the IPs for GPMI and BCH. Different IPs have
 different features, such as the BCH's maximum ECC strength:

     imx23/imx28 -- the BCH's maximum ECC strength is 20
     imx6q       -- the BCH's maximum ECC strength is 40
     imx6sx      -- the BCH's maximum ECC strength is 62

This patch does the following things:

  [1] add a new data structure, gpmi_devdata{}, to store the information for
      each IP. Besides the IP version, we store the following information:
         <1> BCH's maximum ECC strength.
         <2> the maximum chain delay in ns used by the EDO mode.

      but we may add more information in future.

  [2] add the gpmi_devdata_imx{23|28|6q} to replace the gpmi_ids.

  [3] simplify the code by using the ECC strength from gpmi_devdata, such as
      gpmi_check_ecc() and legacy_set_geometry();

  [4] use the maximum chain delay to initialize the EDO mode,
      see gpmi_compute_edo_timing().

  [5] rewrite the macros, such GPMI_IS_MX{23|28|6Q}.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

1 files changed, 28 insertions, 25 deletions

diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
index bb77f750e75a..e88d64e1e963 100644
--- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
@@ -53,6 +53,24 @@ static struct nand_ecclayout gpmi_hw_ecclayout = {
 	.oobfree = { {.offset = 0, .length = 0} }
 };
 
+static const struct gpmi_devdata gpmi_devdata_imx23 = {
+	.type = IS_MX23,
+	.bch_max_ecc_strength = 20,
+	.max_chain_delay = 16,
+};
+
+static const struct gpmi_devdata gpmi_devdata_imx28 = {
+	.type = IS_MX28,
+	.bch_max_ecc_strength = 20,
+	.max_chain_delay = 16,
+};
+
+static const struct gpmi_devdata gpmi_devdata_imx6q = {
+	.type = IS_MX6Q,
+	.bch_max_ecc_strength = 40,
+	.max_chain_delay = 12,
+};
+
 static irqreturn_t bch_irq(int irq, void *cookie)
 {
 	struct gpmi_nand_data *this = cookie;
@@ -102,14 +120,8 @@ static inline bool gpmi_check_ecc(struct gpmi_nand_data *this)
 		/* The mx23/mx28 only support the GF13. */
 		if (geo->gf_len == 14)
 			return false;
-
-		if (geo->ecc_strength > MXS_ECC_STRENGTH_MAX)
-			return false;
-	} else if (GPMI_IS_MX6Q(this)) {
-		if (geo->ecc_strength > MX6_ECC_STRENGTH_MAX)
-			return false;
 	}
-	return true;
+	return geo->ecc_strength <= this->devdata->bch_max_ecc_strength;
 }
 
 /*
@@ -270,8 +282,7 @@ static int legacy_set_geometry(struct gpmi_nand_data *this)
 			"We can not support this nand chip."
 			" Its required ecc strength(%d) is beyond our"
 			" capability(%d).\n", geo->ecc_strength,
-			(GPMI_IS_MX6Q(this) ? MX6_ECC_STRENGTH_MAX
-					: MXS_ECC_STRENGTH_MAX));
+			this->devdata->bch_max_ecc_strength);
 		return -EINVAL;
 	}
 
@@ -1740,23 +1751,16 @@ err_out:
 	return ret;
 }
 
-static const struct platform_device_id gpmi_ids[] = {
-	{ .name = "imx23-gpmi-nand", .driver_data = IS_MX23, },
-	{ .name = "imx28-gpmi-nand", .driver_data = IS_MX28, },
-	{ .name = "imx6q-gpmi-nand", .driver_data = IS_MX6Q, },
-	{}
-};
-
 static const struct of_device_id gpmi_nand_id_table[] = {
 	{
 		.compatible = "fsl,imx23-gpmi-nand",
-		.data = (void *)&gpmi_ids[IS_MX23],
+		.data = (void *)&gpmi_devdata_imx23,
 	}, {
 		.compatible = "fsl,imx28-gpmi-nand",
-		.data = (void *)&gpmi_ids[IS_MX28],
+		.data = (void *)&gpmi_devdata_imx28,
 	}, {
 		.compatible = "fsl,imx6q-gpmi-nand",
-		.data = (void *)&gpmi_ids[IS_MX6Q],
+		.data = (void *)&gpmi_devdata_imx6q,
 	}, {}
 };
 MODULE_DEVICE_TABLE(of, gpmi_nand_id_table);
@@ -1767,18 +1771,18 @@ static int gpmi_nand_probe(struct platform_device *pdev)
 	const struct of_device_id *of_id;
 	int ret;
 
+	this = devm_kzalloc(&pdev->dev, sizeof(*this), GFP_KERNEL);
+	if (!this)
+		return -ENOMEM;
+
 	of_id = of_match_device(gpmi_nand_id_table, &pdev->dev);
 	if (of_id) {
-		pdev->id_entry = of_id->data;
+		this->devdata = of_id->data;
 	} else {
 		dev_err(&pdev->dev, "Failed to find the right device id.\n");
 		return -ENODEV;
 	}
 
-	this = devm_kzalloc(&pdev->dev, sizeof(*this), GFP_KERNEL);
-	if (!this)
-		return -ENOMEM;
-
 	platform_set_drvdata(pdev, this);
 	this->pdev  = pdev;
 	this->dev   = &pdev->dev;
@@ -1823,7 +1827,6 @@ static struct platform_driver gpmi_nand_driver = {
 	},
 	.probe   = gpmi_nand_probe,
 	.remove  = gpmi_nand_remove,
-	.id_table = gpmi_ids,
 };
 module_platform_driver(gpmi_nand_driver);