mtd: spi-nor: cadence-quadspi: Fix cqspi_command_read() definition

n_tx was never used, drop it. Replace 'const u8 *txbuf' with 'u8 opcode',
to comply with the SPI NOR int (*read_reg)() method. The 'const'
qualifier has no meaning for parameters passed by value, drop it.
Going furher, the opcode was passed to cqspi_calc_rdreg() and never used,
drop it.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>

drivers/mtd/spi-nor/cadence-quadspi.c

@@ -285,7 +285,7 @@ static irqreturn_t cqspi_irq_handler(int this_irq, void *dev)
 	return IRQ_HANDLED;
 }
 
-static unsigned int cqspi_calc_rdreg(struct spi_nor *nor, const u8 opcode)
+static unsigned int cqspi_calc_rdreg(struct spi_nor *nor)
 {
 	struct cqspi_flash_pdata *f_pdata = nor->priv;
 	u32 rdreg = 0;
@@ -354,8 +354,7 @@ static int cqspi_exec_flash_cmd(struct cqspi_st *cqspi, unsigned int reg)
 	return cqspi_wait_idle(cqspi);
 }
 
-static int cqspi_command_read(struct spi_nor *nor,
-			      const u8 *txbuf, const unsigned n_tx,
+static int cqspi_command_read(struct spi_nor *nor, u8 opcode,
 			      u8 *rxbuf, size_t n_rx)
 {
 	struct cqspi_flash_pdata *f_pdata = nor->priv;
@@ -373,9 +372,9 @@ static int cqspi_command_read(struct spi_nor *nor,
 		return -EINVAL;
 	}
 
-	reg = txbuf[0] << CQSPI_REG_CMDCTRL_OPCODE_LSB;
+	reg = opcode << CQSPI_REG_CMDCTRL_OPCODE_LSB;
 
-	rdreg = cqspi_calc_rdreg(nor, txbuf[0]);
+	rdreg = cqspi_calc_rdreg(nor);
 	writel(rdreg, reg_base + CQSPI_REG_RD_INSTR);
 
 	reg |= (0x1 << CQSPI_REG_CMDCTRL_RD_EN_LSB);
@@ -471,7 +470,7 @@ static int cqspi_read_setup(struct spi_nor *nor)
 	unsigned int reg;
 
 	reg = nor->read_opcode << CQSPI_REG_RD_INSTR_OPCODE_LSB;
-	reg |= cqspi_calc_rdreg(nor, nor->read_opcode);
+	reg |= cqspi_calc_rdreg(nor);
 
 	/* Setup dummy clock cycles */
 	dummy_clk = nor->read_dummy;
@@ -604,7 +603,7 @@ static int cqspi_write_setup(struct spi_nor *nor)
 	/* Set opcode. */
 	reg = nor->program_opcode << CQSPI_REG_WR_INSTR_OPCODE_LSB;
 	writel(reg, reg_base + CQSPI_REG_WR_INSTR);
-	reg = cqspi_calc_rdreg(nor, nor->program_opcode);
+	reg = cqspi_calc_rdreg(nor);
 	writel(reg, reg_base + CQSPI_REG_RD_INSTR);
 
 	reg = readl(reg_base + CQSPI_REG_SIZE);
@@ -1087,7 +1086,7 @@ static int cqspi_read_reg(struct spi_nor *nor, u8 opcode, u8 *buf, size_t len)
 
 	ret = cqspi_set_protocol(nor, 0);
 	if (!ret)
-		ret = cqspi_command_read(nor, &opcode, 1, buf, len);
+		ret = cqspi_command_read(nor, opcode, buf, len);
 
 	return ret;
 }