diff mbox series

[v3,11/17] mtd: spinand: Allow enabling/disabling Octal DTR mode in the core

Message ID 20220101074250.14443-12-a-nandan@ti.com
State New
Headers show
Series mtd: spinand: Add Octal DTR SPI (8D-8D-8D) mode support | expand

Commit Message

Apurva Nandan Jan. 1, 2022, 7:42 a.m. UTC
Enable Octal DTR SPI mode, i.e. 8D-8D-8D mode, if the SPI NAND flash
device supports it. Mixed OSPI (1S-1S-8S & 1S-8S-8S), mixed DTR modes
(1S-1D-8D), etc. aren't supported yet.

The method to switch to Octal DTR SPI mode may vary across
manufacturers. For example, for Winbond, it is enabled by writing
values to the volatile configuration register. So, let the
manufacturer's code have their own implementation for switching to
Octal DTR SPI mode.

Check for the SPI NAND device's support for Octal DTR mode using
spinand flags, and if the data_ops and ctrl_ops are 8D-8D-8D, call
change_mode() manufacturer op. If the SPI controller doesn't
supports these modes, the selected data_ops and ctrl_ops will
prevent switching to the Octal DTR mode. And finally update the
spinand protocol and ctrl_ops on success. Similarly, for disabling
Octal DTR mode, call change_mode(), and update protocol and ctrl_ops.

Signed-off-by: Apurva Nandan <a-nandan@ti.com>
---
 drivers/mtd/nand/spi/core.c | 79 +++++++++++++++++++++++++++++++++++++
 include/linux/mtd/spinand.h |  1 +
 2 files changed, 80 insertions(+)

Comments

Boris Brezillon Jan. 3, 2022, 10:14 a.m. UTC | #1
On Sat, 1 Jan 2022 13:12:44 +0530
Apurva Nandan <a-nandan@ti.com> wrote:

> Enable Octal DTR SPI mode, i.e. 8D-8D-8D mode, if the SPI NAND flash
> device supports it. Mixed OSPI (1S-1S-8S & 1S-8S-8S), mixed DTR modes
> (1S-1D-8D), etc. aren't supported yet.
> 
> The method to switch to Octal DTR SPI mode may vary across
> manufacturers. For example, for Winbond, it is enabled by writing
> values to the volatile configuration register. So, let the
> manufacturer's code have their own implementation for switching to
> Octal DTR SPI mode.
> 
> Check for the SPI NAND device's support for Octal DTR mode using
> spinand flags, and if the data_ops and ctrl_ops are 8D-8D-8D, call
> change_mode() manufacturer op. If the SPI controller doesn't
> supports these modes, the selected data_ops and ctrl_ops will
> prevent switching to the Octal DTR mode. And finally update the
> spinand protocol and ctrl_ops on success. Similarly, for disabling
> Octal DTR mode, call change_mode(), and update protocol and ctrl_ops.
> 
> Signed-off-by: Apurva Nandan <a-nandan@ti.com>
> ---
>  drivers/mtd/nand/spi/core.c | 79 +++++++++++++++++++++++++++++++++++++
>  include/linux/mtd/spinand.h |  1 +
>  2 files changed, 80 insertions(+)
> 
> diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
> index 1a602e4dd6bd..2fd08085db6f 100644
> --- a/drivers/mtd/nand/spi/core.c
> +++ b/drivers/mtd/nand/spi/core.c
> @@ -1067,6 +1067,81 @@ spinand_select_ctrl_ops_variant(struct spinand_device *spinand,
>  	return NULL;
>  }
>  
> +static bool spinand_op_is_octal_dtr(const struct spi_mem_op *op)
> +{
> +	return  op->cmd.buswidth == 8 && op->cmd.dtr &&
> +		op->addr.buswidth == 8 && op->addr.dtr &&
> +		op->data.buswidth == 8 && op->data.dtr;
> +}
> +
> +static int spinand_init_octal_dtr_enable(struct spinand_device *spinand)
> +{
> +	struct device *dev = &spinand->spimem->spi->dev;
> +	const struct spinand_ctrl_ops *octal_dtr_ctrl_ops;
> +	int ret;
> +
> +	if (!(spinand->flags & SPINAND_HAS_OCTAL_DTR_BIT))
> +		return 0;
> +
> +	if (!(spinand_op_is_octal_dtr(spinand->data_ops.read_cache) &&
> +	      spinand_op_is_octal_dtr(spinand->data_ops.write_cache) &&
> +	      spinand_op_is_octal_dtr(spinand->data_ops.update_cache)))
> +		return 0;
> +
> +	octal_dtr_ctrl_ops = spinand_select_ctrl_ops_variant(spinand,
> +					spinand->desc_entry->ctrl_ops_variants,
> +					SPINAND_8D_8D_8D);
> +
> +	if (!octal_dtr_ctrl_ops)
> +		return 0;
> +
> +	if (!spinand->manufacturer->ops->change_mode) {
> +		dev_dbg(dev,
> +			"Missing ->change_mode(), unable to switch mode\n");
> +		return -EINVAL;

Looks like something that's worth printing at the info level, and I
think returning EOPNOTSUPP would be more appropriate.

> +	}
> +
> +	ret = spinand->manufacturer->ops->change_mode(spinand,
> +						      SPINAND_8D_8D_8D);
> +	if (ret) {
> +		dev_err(dev,
> +			"Failed to enable Octal DTR SPI mode (err = %d)\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	spinand->protocol = SPINAND_8D_8D_8D;
> +	spinand->ctrl_ops = octal_dtr_ctrl_ops;
> +
> +	dev_dbg(dev,
> +		"%s SPI NAND switched to Octal DTR SPI (8D-8D-8D) mode\n",
> +		spinand->manufacturer->name);
> +	return 0;
> +}
> +
> +static int spinand_init_octal_dtr_disable(struct spinand_device *spinand)

This function is never used. I guess it should be called in the
suspend/shutdown path, at least.

> +{
> +	struct device *dev = &spinand->spimem->spi->dev;
> +	int ret;
> +
> +	if (!spinand->manufacturer->ops->change_mode)
> +		return -EINVAL;
> +
> +	ret = spinand->manufacturer->ops->change_mode(spinand,
> +						      SPINAND_1S_1S_1S);
> +
> +	if (ret) {
> +		dev_err(dev,
> +			"Failed to disable Octal DTR SPI mode (err = %d)\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	spinand->protocol = SPINAND_1S_1S_1S;
> +	spinand->ctrl_ops = &spinand_default_ctrl_ops;
> +	return 0;
> +}
> +
>  /**
>   * spinand_match_and_init() - Try to find a match between a device ID and an
>   *			      entry in a spinand_info table
> @@ -1203,6 +1278,10 @@ static int spinand_init_flash(struct spinand_device *spinand)
>  			break;
>  	}
>  
> +	ret = spinand_init_octal_dtr_enable(spinand);
> +	if (ret)
> +		return ret;
> +
>  	if (ret)
>  		spinand_manufacturer_cleanup(spinand);
>  
> diff --git a/include/linux/mtd/spinand.h b/include/linux/mtd/spinand.h
> index a8c071983a27..f12aa4516fab 100644
> --- a/include/linux/mtd/spinand.h
> +++ b/include/linux/mtd/spinand.h
> @@ -417,6 +417,7 @@ struct spinand_ecc_info {
>  
>  #define SPINAND_HAS_QE_BIT		BIT(0)
>  #define SPINAND_HAS_CR_FEAT_BIT		BIT(1)
> +#define SPINAND_HAS_OCTAL_DTR_BIT	BIT(2)

Do we really need a new flag for this? Isn't the template op
initialization enough to reflect whether the NAND and controller can do
8DTR or not?

>  
>  /**
>   * struct spinand_ondie_ecc_conf - private SPI-NAND on-die ECC engine structure
diff mbox series

Patch

diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index 1a602e4dd6bd..2fd08085db6f 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -1067,6 +1067,81 @@  spinand_select_ctrl_ops_variant(struct spinand_device *spinand,
 	return NULL;
 }
 
+static bool spinand_op_is_octal_dtr(const struct spi_mem_op *op)
+{
+	return  op->cmd.buswidth == 8 && op->cmd.dtr &&
+		op->addr.buswidth == 8 && op->addr.dtr &&
+		op->data.buswidth == 8 && op->data.dtr;
+}
+
+static int spinand_init_octal_dtr_enable(struct spinand_device *spinand)
+{
+	struct device *dev = &spinand->spimem->spi->dev;
+	const struct spinand_ctrl_ops *octal_dtr_ctrl_ops;
+	int ret;
+
+	if (!(spinand->flags & SPINAND_HAS_OCTAL_DTR_BIT))
+		return 0;
+
+	if (!(spinand_op_is_octal_dtr(spinand->data_ops.read_cache) &&
+	      spinand_op_is_octal_dtr(spinand->data_ops.write_cache) &&
+	      spinand_op_is_octal_dtr(spinand->data_ops.update_cache)))
+		return 0;
+
+	octal_dtr_ctrl_ops = spinand_select_ctrl_ops_variant(spinand,
+					spinand->desc_entry->ctrl_ops_variants,
+					SPINAND_8D_8D_8D);
+
+	if (!octal_dtr_ctrl_ops)
+		return 0;
+
+	if (!spinand->manufacturer->ops->change_mode) {
+		dev_dbg(dev,
+			"Missing ->change_mode(), unable to switch mode\n");
+		return -EINVAL;
+	}
+
+	ret = spinand->manufacturer->ops->change_mode(spinand,
+						      SPINAND_8D_8D_8D);
+	if (ret) {
+		dev_err(dev,
+			"Failed to enable Octal DTR SPI mode (err = %d)\n",
+			ret);
+		return ret;
+	}
+
+	spinand->protocol = SPINAND_8D_8D_8D;
+	spinand->ctrl_ops = octal_dtr_ctrl_ops;
+
+	dev_dbg(dev,
+		"%s SPI NAND switched to Octal DTR SPI (8D-8D-8D) mode\n",
+		spinand->manufacturer->name);
+	return 0;
+}
+
+static int spinand_init_octal_dtr_disable(struct spinand_device *spinand)
+{
+	struct device *dev = &spinand->spimem->spi->dev;
+	int ret;
+
+	if (!spinand->manufacturer->ops->change_mode)
+		return -EINVAL;
+
+	ret = spinand->manufacturer->ops->change_mode(spinand,
+						      SPINAND_1S_1S_1S);
+
+	if (ret) {
+		dev_err(dev,
+			"Failed to disable Octal DTR SPI mode (err = %d)\n",
+			ret);
+		return ret;
+	}
+
+	spinand->protocol = SPINAND_1S_1S_1S;
+	spinand->ctrl_ops = &spinand_default_ctrl_ops;
+	return 0;
+}
+
 /**
  * spinand_match_and_init() - Try to find a match between a device ID and an
  *			      entry in a spinand_info table
@@ -1203,6 +1278,10 @@  static int spinand_init_flash(struct spinand_device *spinand)
 			break;
 	}
 
+	ret = spinand_init_octal_dtr_enable(spinand);
+	if (ret)
+		return ret;
+
 	if (ret)
 		spinand_manufacturer_cleanup(spinand);
 
diff --git a/include/linux/mtd/spinand.h b/include/linux/mtd/spinand.h
index a8c071983a27..f12aa4516fab 100644
--- a/include/linux/mtd/spinand.h
+++ b/include/linux/mtd/spinand.h
@@ -417,6 +417,7 @@  struct spinand_ecc_info {
 
 #define SPINAND_HAS_QE_BIT		BIT(0)
 #define SPINAND_HAS_CR_FEAT_BIT		BIT(1)
+#define SPINAND_HAS_OCTAL_DTR_BIT	BIT(2)
 
 /**
  * struct spinand_ondie_ecc_conf - private SPI-NAND on-die ECC engine structure