[U-Boot] [PATCH 17/34] spi: mpc8xxx: Make code more readable

Jagan Teki
2018-11-20T12:47:57Z

From: Mario Six <mario.six@gdsys.cc>

Introduce the to_prescale_mod and set_char_len inline functions to make
the code more readable.

Note that the added "if (bitlen > 16)" check does not change the
semantics of the current code, and hence only preserves the current
error (this will be fixed in a later patch in the series).

Signed-off-by: Mario Six <mario.six@gdsys.cc>
---
drivers/spi/mpc8xxx_spi.c | 27 +++++++++++++++++++--------
1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/drivers/spi/mpc8xxx_spi.c b/drivers/spi/mpc8xxx_spi.c
index 2a0f3cc06a..83fd8b3cc1 100644
--- a/drivers/spi/mpc8xxx_spi.c
+++ b/drivers/spi/mpc8xxx_spi.c
@@ -30,6 +30,16 @@ enum {
SPI_COM_LST = BIT(31 - 9),
};

+static inline u32 to_prescale_mod(u32 val)
+{
+ return (min(val, (u32)15) << 16);
+}
+
+static void set_char_len(spi8xxx_t *spi, u32 val)
+{
+ clrsetbits_be32(&spi->mode, SPI_MODE_LEN_MASK, (val << 20));
+}
+
#define SPI_TIMEOUT 1000

struct spi_slave *spi_setup_slave(uint bus, uint cs, uint max_hz, uint mode)
@@ -66,7 +76,7 @@ void spi_init(void)
*/
out_be32(&spi->mode, SPI_MODE_REV | SPI_MODE_MS | SPI_MODE_EN);
/* Use SYSCLK / 8 (16.67MHz typ.) */
- clrsetbits_be32(&spi->mode, 0x000f0000, BIT(16));
+ clrsetbits_be32(&spi->mode, SPI_MODE_PM_MASK, to_prescale_mod(1));
/* Clear all SPI events */
setbits_be32(&spi->event, 0xffffffff);
/* Mask all SPI interrupts */
@@ -119,13 +129,14 @@ int spi_xfer(struct spi_slave *slave, uint bitlen, const void *dout, void *din,

clrbits_be32(&spi->mode, SPI_MODE_EN);

- if (bitlen <= 4) {
- clrsetbits_be32(&spi->mode, 0x00f00000, (3 << 20));
- } else if (bitlen <= 16) {
- clrsetbits_be32(&spi->mode, 0x00f00000,
- ((bitlen - 1) << 20));
- } else {
- clrbits_be32(&spi->mode, 0x00f00000);
+ if (bitlen <= 4)
+ set_char_len(spi, 3);
+ else if (bitlen <= 16)
+ set_char_len(spi, bitlen - 1);
+ else
+ set_char_len(spi, 0);
+
+ if (bitlen > 16) {
/* Set up the next iteration if sending > 32 bits */
bitlen -= 32;
dout += 4;
--
2.18.0.321.gffc6fa0e3