spi: bcm63xx-hsspi: bcmbca-hsspi: fix _be16 type usage

sparse tool report warnings: drivers/spi/spi-bcm63xx-hsspi.c:197:31:
sparse: sparse: cast from restricted __be16.

The controller requires big endian 16 bit data. Define an intermediate
u16 value and use __be16 piointer dereferncing for the data to avoid
directly casting to u16 and sparse warning.

Fixes: 85a84a61 ("spi: bcm63xx-hsspi: Endianness fix for ARM based SoC")
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202302110438.sQwQnU54-lkp@intel.com/Signed-off-by: William Zhang <william.zhang@broadcom.com>
Link: https://lore.kernel.org/r/20230211032759.72967-1-william.zhang@broadcom.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-bcm63xx-hsspi.c

@@ -350,7 +350,7 @@ static int bcm63xx_hsspi_do_prepend_txrx(struct spi_device *spi,
 {
 	struct bcm63xx_hsspi *bs = spi_master_get_devdata(spi->master);
 	unsigned int chip_select = spi->chip_select;
-	u16 opcode = 0;
+	u16 opcode = 0, val;
 	const u8 *tx = t->tx_buf;
 	u8 *rx = t->rx_buf;
 	u32 reg = 0;
@@ -401,7 +401,8 @@ static int bcm63xx_hsspi_do_prepend_txrx(struct spi_device *spi,
 		memcpy_toio(bs->fifo + HSSPI_OPCODE_LEN + bs->prepend_cnt, tx,
 			    t->len);
 
-	__raw_writew((u16)cpu_to_be16(opcode | t->len), bs->fifo);
+	*(__be16 *)(&val) = cpu_to_be16(opcode | t->len);
+	__raw_writew(val, bs->fifo);
 	/* enable interrupt */
 	if (bs->wait_mode == HSSPI_WAIT_MODE_INTR)
 		__raw_writel(HSSPI_PINGx_CMD_DONE(0), bs->regs + HSSPI_INT_MASK_REG);
@@ -468,7 +469,7 @@ static int bcm63xx_hsspi_do_txrx(struct spi_device *spi, struct spi_transfer *t)
 {
 	struct bcm63xx_hsspi *bs = spi_master_get_devdata(spi->master);
 	unsigned int chip_select = spi->chip_select;
-	u16 opcode = 0;
+	u16 opcode = 0, val;
 	int pending = t->len;
 	int step_size = HSSPI_BUFFER_LEN;
 	const u8 *tx = t->tx_buf;
@@ -511,7 +512,8 @@ static int bcm63xx_hsspi_do_txrx(struct spi_device *spi, struct spi_transfer *t)
 			tx += curr_step;
 		}
 
-		__raw_writew((u16)cpu_to_be16(opcode | curr_step), bs->fifo);
+		*(__be16 *)(&val) = cpu_to_be16(opcode | curr_step);
+		__raw_writew(val, bs->fifo);
 
 		/* enable interrupt */
 		if (bs->wait_mode == HSSPI_WAIT_MODE_INTR)

drivers/spi/spi-bcmbca-hsspi.c

@@ -252,7 +252,7 @@ static int bcmbca_hsspi_do_txrx(struct spi_device *spi, struct spi_transfer *t,
 {
 	struct bcmbca_hsspi *bs = spi_master_get_devdata(spi->master);
 	unsigned int chip_select = spi->chip_select;
-	u16 opcode = 0;
+	u16 opcode = 0, val;
 	int pending = t->len;
 	int step_size = HSSPI_BUFFER_LEN;
 	const u8 *tx = t->tx_buf;
@@ -292,7 +292,9 @@ static int bcmbca_hsspi_do_txrx(struct spi_device *spi, struct spi_transfer *t,
 			memcpy_toio(bs->fifo + HSSPI_OPCODE_LEN, tx, curr_step);
 			tx += curr_step;
 		}
-		__raw_writew((u16)cpu_to_be16(opcode | curr_step), bs->fifo);
+
+		*(__be16 *)(&val) = cpu_to_be16(opcode | curr_step);
+		__raw_writew(val, bs->fifo);
 
 		/* enable interrupt */
 		if (bs->wait_mode == HSSPI_WAIT_MODE_INTR)