misc: pmic: fix regression in pmic_fsl.c (SPI)

This fixes write access to PMIC registers, the bug was
introduced partly in commit 64aac65099 and in commit c9fe76dd91.
It was tested on an i.mx31 with a mc13783.

Signed-off-by: Helmut Raiger <helmut.raiger@hale.at>
Acked-by: Stefano Babic <sbabic@denx.de>

drivers/misc/pmic_fsl.c

@@ -29,10 +29,7 @@
 #if defined(CONFIG_PMIC_SPI)
 static u32 pmic_spi_prepare_tx(u32 reg, u32 *val, u32 write)
 {
-	if ((val == NULL) && (write))
-		return *val & ~(1 << 31);
-	else
-		return (write << 31) | (reg << 25) | (*val & 0x00FFFFFF);
+	return (write << 31) | (reg << 25) | (*val & 0x00FFFFFF);
 }
 #endif
 

drivers/misc/pmic_spi.c

@@ -76,8 +76,7 @@ static u32 pmic_reg(struct pmic *p, u32 reg, u32 *val, u32 write)
 	}
 
 	if (write) {
-		pmic_tx = p->hw.spi.prepare_tx(0, NULL, write);
-		pmic_tx &= ~(1 << 31);
+		pmic_tx = p->hw.spi.prepare_tx(reg, val, 0);
 		tmp = cpu_to_be32(pmic_tx);
 		if (spi_xfer(slave, pmic_spi_bitlen, &tmp, &pmic_rx,
 			pmic_spi_flags)) {