mtd: spinand: winbond: Enable high-speed modes on w35n0xjw

w35n0xjw chips can run at up to 166MHz in octal mode, but this is only
possible after programming various VCR registers.

Implement the new ->configure_chip() hook for this purpose.

Signed-off-by: Miquel Raynal <[email protected]>

Author: miquelraynal

drivers/mtd/nand/spi/core.c

@@ -360,7 +360,7 @@ static void spinand_ondie_ecc_save_status(struct nand_device *nand, u8 status)
 		engine_conf->status = status;
 }
 
-static int spinand_write_enable_op(struct spinand_device *spinand)
+int spinand_write_enable_op(struct spinand_device *spinand)
 {
 	struct spi_mem_op op = SPINAND_WR_EN_DIS_1S_0_0_OP(true);
 

drivers/mtd/nand/spi/winbond.c

@@ -11,6 +11,7 @@
 #include <linux/kernel.h>
 #include <linux/mtd/spinand.h>
 #include <linux/units.h>
+#include <linux/delay.h>
 
 #define SPINAND_MFR_WINBOND		0xEF
 
@@ -21,14 +22,26 @@
 #define W25N0XJW_SR4			0xD0
 #define W25N0XJW_SR4_HS			BIT(2)
 
+#define W35N01JW_VCR_IO_MODE			0x00
+#define W35N01JW_VCR_IO_MODE_SINGLE_SDR		0xFF
+#define W35N01JW_VCR_IO_MODE_OCTAL_SDR		0xDF
+#define W35N01JW_VCR_IO_MODE_OCTAL_DDR_DS	0xE7
+#define W35N01JW_VCR_IO_MODE_OCTAL_DDR		0xC7
+#define W35N01JW_VCR_DUMMY_CLOCK_REG	0x01
+
 /*
  * "X2" in the core is equivalent to "dual output" in the datasheets,
  * "X4" in the core is equivalent to "quad output" in the datasheets.
  */
 
 static SPINAND_OP_VARIANTS(read_cache_octal_variants,
+		SPINAND_PAGE_READ_FROM_CACHE_1S_1D_8D_OP(0, 3, NULL, 0, 120 * HZ_PER_MHZ),
 		SPINAND_PAGE_READ_FROM_CACHE_1S_1D_8D_OP(0, 2, NULL, 0, 105 * HZ_PER_MHZ),
+		SPINAND_PAGE_READ_FROM_CACHE_1S_8S_8S_OP(0, 20, NULL, 0, 0),
 		SPINAND_PAGE_READ_FROM_CACHE_1S_8S_8S_OP(0, 16, NULL, 0, 162 * HZ_PER_MHZ),
+		SPINAND_PAGE_READ_FROM_CACHE_1S_8S_8S_OP(0, 12, NULL, 0, 124 * HZ_PER_MHZ),
+		SPINAND_PAGE_READ_FROM_CACHE_1S_8S_8S_OP(0, 8, NULL, 0, 86 * HZ_PER_MHZ),
+		SPINAND_PAGE_READ_FROM_CACHE_1S_1S_8S_OP(0, 2, NULL, 0, 0),
 		SPINAND_PAGE_READ_FROM_CACHE_1S_1S_8S_OP(0, 1, NULL, 0, 133 * HZ_PER_MHZ),
 		SPINAND_PAGE_READ_FROM_CACHE_FAST_1S_1S_1S_OP(0, 1, NULL, 0, 0),
 		SPINAND_PAGE_READ_FROM_CACHE_1S_1S_1S_OP(0, 1, NULL, 0, 0));
@@ -269,6 +282,79 @@ static int w25n0xjw_hs_cfg(struct spinand_device *spinand)
 	return 0;
 }
 
+static int w35n0xjw_write_vcr(struct spinand_device *spinand, u8 reg, u8 val)
+{
+	struct spi_mem_op op =
+		SPI_MEM_OP(SPI_MEM_OP_CMD(0x81, 1),
+			   SPI_MEM_OP_ADDR(3, reg, 1),
+			   SPI_MEM_OP_NO_DUMMY,
+			   SPI_MEM_OP_DATA_OUT(1, spinand->scratchbuf, 1));
+	int ret;
+
+	*spinand->scratchbuf = val;
+
+	ret = spinand_write_enable_op(spinand);
+	if (ret)
+		return ret;
+
+	ret = spi_mem_exec_op(spinand->spimem, &op);
+	if (ret)
+		return ret;
+
+	/*
+	 * Write VCR operation doesn't set the busy bit in SR, which means we
+	 * cannot perform a status poll. Minimum time of 50ns is needed to
+	 * complete the write.
+	 */
+	ndelay(50);
+
+	return 0;
+}
+
+static int w35n0xjw_vcr_cfg(struct spinand_device *spinand)
+{
+	const struct spi_mem_op *op;
+	unsigned int dummy_cycles;
+	bool dtr, single;
+	u8 io_mode;
+	int ret;
+
+	op = spinand->op_templates.read_cache;
+
+	single = (op->cmd.buswidth == 1 && op->addr.buswidth == 1 && op->data.buswidth == 1);
+	dtr = (op->cmd.dtr || op->addr.dtr || op->data.dtr);
+	if (single && !dtr)
+		io_mode = W35N01JW_VCR_IO_MODE_SINGLE_SDR;
+	else if (!single && !dtr)
+		io_mode = W35N01JW_VCR_IO_MODE_OCTAL_SDR;
+	else if (!single && dtr)
+		io_mode = W35N01JW_VCR_IO_MODE_OCTAL_DDR;
+	else
+		return -EINVAL;
+
+	ret = w35n0xjw_write_vcr(spinand, W35N01JW_VCR_IO_MODE, io_mode);
+	if (ret)
+		return ret;
+
+	dummy_cycles = ((op->dummy.nbytes * 8) / op->dummy.buswidth) / (op->dummy.dtr ? 2 : 1);
+	switch (dummy_cycles) {
+	case 8:
+	case 12:
+	case 16:
+	case 20:
+	case 24:
+	case 28:
+		break;
+	default:
+		return -EINVAL;
+	}
+	ret = w35n0xjw_write_vcr(spinand, W35N01JW_VCR_DUMMY_CLOCK_REG, dummy_cycles);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 static const struct spinand_info winbond_spinand_table[] = {
 	/* 512M-bit densities */
 	SPINAND_INFO("W25N512GW", /* 1.8V */
@@ -326,7 +412,8 @@ static const struct spinand_info winbond_spinand_table[] = {
 					      &write_cache_octal_variants,
 					      &update_cache_octal_variants),
 		     0,
-		     SPINAND_ECCINFO(&w35n01jw_ooblayout, NULL)),
+		     SPINAND_ECCINFO(&w35n01jw_ooblayout, NULL),
+		     SPINAND_CONFIGURE_CHIP(w35n0xjw_vcr_cfg)),
 	SPINAND_INFO("W35N02JW", /* 1.8V */
 		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0xdf, 0x22),
 		     NAND_MEMORG(1, 4096, 128, 64, 512, 10, 1, 2, 1),
@@ -335,7 +422,8 @@ static const struct spinand_info winbond_spinand_table[] = {
 					      &write_cache_octal_variants,
 					      &update_cache_octal_variants),
 		     0,
-		     SPINAND_ECCINFO(&w35n01jw_ooblayout, NULL)),
+		     SPINAND_ECCINFO(&w35n01jw_ooblayout, NULL),
+		     SPINAND_CONFIGURE_CHIP(w35n0xjw_vcr_cfg)),
 	SPINAND_INFO("W35N04JW", /* 1.8V */
 		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0xdf, 0x23),
 		     NAND_MEMORG(1, 4096, 128, 64, 512, 10, 1, 4, 1),
@@ -344,7 +432,8 @@ static const struct spinand_info winbond_spinand_table[] = {
 					      &write_cache_octal_variants,
 					      &update_cache_octal_variants),
 		     0,
-		     SPINAND_ECCINFO(&w35n01jw_ooblayout, NULL)),
+		     SPINAND_ECCINFO(&w35n01jw_ooblayout, NULL),
+		     SPINAND_CONFIGURE_CHIP(w35n0xjw_vcr_cfg)),
 	/* 2G-bit densities */
 	SPINAND_INFO("W25M02GV", /* 2x1G-bit 3.3V */
 		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0xab, 0x21),

include/linux/mtd/spinand.h

@@ -741,6 +741,7 @@ int spinand_match_and_init(struct spinand_device *spinand,
 int spinand_upd_cfg(struct spinand_device *spinand, u8 mask, u8 val);
 int spinand_read_reg_op(struct spinand_device *spinand, u8 reg, u8 *val);
 int spinand_write_reg_op(struct spinand_device *spinand, u8 reg, u8 val);
+int spinand_write_enable_op(struct spinand_device *spinand);
 int spinand_select_target(struct spinand_device *spinand, unsigned int target);
 
 int spinand_wait(struct spinand_device *spinand, unsigned long initial_delay_us,