[PATCH v2 3/8] spi: stm32: use bitfield macros

From: Alain Volmat
Date: Fri Feb 05 2021 - 14:06:10 EST


From: Amelie Delaunay <amelie.delaunay@xxxxxxxxxxx>

To avoid defining shift and mask separately and hand-coding the bit
manipulation, use the bitfield macros.

Signed-off-by: Amelie Delaunay <amelie.delaunay@xxxxxxxxxxx>
Signed-off-by: Alain Volmat <alain.volmat@xxxxxxxxxxx>
---
v2: reordered within the serie

drivers/spi/spi-stm32.c | 54 ++++++++++++++---------------------------
1 file changed, 18 insertions(+), 36 deletions(-)

diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index 2b4ea4cba00b..a46132e81533 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -5,6 +5,7 @@
// Copyright (C) 2017, STMicroelectronics - All Rights Reserved
// Author(s): Amelie Delaunay <amelie.delaunay@xxxxxx> for STMicroelectronics.

+#include <linux/bitfield.h>
#include <linux/debugfs.h>
#include <linux/clk.h>
#include <linux/delay.h>
@@ -94,27 +95,22 @@
#define STM32H7_SPI_CR1_SSI BIT(12)

/* STM32H7_SPI_CR2 bit fields */
-#define STM32H7_SPI_CR2_TSIZE_SHIFT 0
#define STM32H7_SPI_CR2_TSIZE GENMASK(15, 0)
+#define STM32H7_SPI_TSIZE_MAX GENMASK(15, 0)

/* STM32H7_SPI_CFG1 bit fields */
-#define STM32H7_SPI_CFG1_DSIZE_SHIFT 0
#define STM32H7_SPI_CFG1_DSIZE GENMASK(4, 0)
-#define STM32H7_SPI_CFG1_FTHLV_SHIFT 5
#define STM32H7_SPI_CFG1_FTHLV GENMASK(8, 5)
#define STM32H7_SPI_CFG1_RXDMAEN BIT(14)
#define STM32H7_SPI_CFG1_TXDMAEN BIT(15)
-#define STM32H7_SPI_CFG1_MBR_SHIFT 28
#define STM32H7_SPI_CFG1_MBR GENMASK(30, 28)
+#define STM32H7_SPI_CFG1_MBR_SHIFT 28
#define STM32H7_SPI_CFG1_MBR_MIN 0
#define STM32H7_SPI_CFG1_MBR_MAX (GENMASK(30, 28) >> 28)

/* STM32H7_SPI_CFG2 bit fields */
-#define STM32H7_SPI_CFG2_MIDI_SHIFT 4
#define STM32H7_SPI_CFG2_MIDI GENMASK(7, 4)
-#define STM32H7_SPI_CFG2_COMM_SHIFT 17
#define STM32H7_SPI_CFG2_COMM GENMASK(18, 17)
-#define STM32H7_SPI_CFG2_SP_SHIFT 19
#define STM32H7_SPI_CFG2_SP GENMASK(21, 19)
#define STM32H7_SPI_CFG2_MASTER BIT(22)
#define STM32H7_SPI_CFG2_LSBFRST BIT(23)
@@ -140,7 +136,6 @@
#define STM32H7_SPI_SR_OVR BIT(6)
#define STM32H7_SPI_SR_MODF BIT(9)
#define STM32H7_SPI_SR_SUSP BIT(11)
-#define STM32H7_SPI_SR_RXPLVL_SHIFT 13
#define STM32H7_SPI_SR_RXPLVL GENMASK(14, 13)
#define STM32H7_SPI_SR_RXWNE BIT(15)

@@ -417,9 +412,7 @@ static int stm32h7_spi_get_bpw_mask(struct stm32_spi *spi)
stm32_spi_set_bits(spi, STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_DSIZE);

cfg1 = readl_relaxed(spi->base + STM32H7_SPI_CFG1);
- max_bpw = (cfg1 & STM32H7_SPI_CFG1_DSIZE) >>
- STM32H7_SPI_CFG1_DSIZE_SHIFT;
- max_bpw += 1;
+ max_bpw = FIELD_GET(STM32H7_SPI_CFG1_DSIZE, cfg1) + 1;

spin_unlock_irqrestore(&spi->lock, flags);

@@ -587,8 +580,7 @@ static void stm32f4_spi_read_rx(struct stm32_spi *spi)
static void stm32h7_spi_read_rxfifo(struct stm32_spi *spi, bool flush)
{
u32 sr = readl_relaxed(spi->base + STM32H7_SPI_SR);
- u32 rxplvl = (sr & STM32H7_SPI_SR_RXPLVL) >>
- STM32H7_SPI_SR_RXPLVL_SHIFT;
+ u32 rxplvl = FIELD_GET(STM32H7_SPI_SR_RXPLVL, sr);

while ((spi->rx_len > 0) &&
((sr & STM32H7_SPI_SR_RXP) ||
@@ -615,8 +607,7 @@ static void stm32h7_spi_read_rxfifo(struct stm32_spi *spi, bool flush)
}

sr = readl_relaxed(spi->base + STM32H7_SPI_SR);
- rxplvl = (sr & STM32H7_SPI_SR_RXPLVL) >>
- STM32H7_SPI_SR_RXPLVL_SHIFT;
+ rxplvl = FIELD_GET(STM32H7_SPI_SR_RXPLVL, sr);
}

dev_dbg(spi->dev, "%s%s: %d bytes left\n", __func__,
@@ -1385,15 +1376,13 @@ static void stm32h7_spi_set_bpw(struct stm32_spi *spi)
bpw = spi->cur_bpw - 1;

cfg1_clrb |= STM32H7_SPI_CFG1_DSIZE;
- cfg1_setb |= (bpw << STM32H7_SPI_CFG1_DSIZE_SHIFT) &
- STM32H7_SPI_CFG1_DSIZE;
+ cfg1_setb |= FIELD_PREP(STM32H7_SPI_CFG1_DSIZE, bpw);

spi->cur_fthlv = stm32h7_spi_prepare_fthlv(spi, spi->cur_xferlen);
fthlv = spi->cur_fthlv - 1;

cfg1_clrb |= STM32H7_SPI_CFG1_FTHLV;
- cfg1_setb |= (fthlv << STM32H7_SPI_CFG1_FTHLV_SHIFT) &
- STM32H7_SPI_CFG1_FTHLV;
+ cfg1_setb |= FIELD_PREP(STM32H7_SPI_CFG1_FTHLV, fthlv);

writel_relaxed(
(readl_relaxed(spi->base + STM32H7_SPI_CFG1) &
@@ -1411,8 +1400,7 @@ static void stm32_spi_set_mbr(struct stm32_spi *spi, u32 mbrdiv)
u32 clrb = 0, setb = 0;

clrb |= spi->cfg->regs->br.mask;
- setb |= ((u32)mbrdiv << spi->cfg->regs->br.shift) &
- spi->cfg->regs->br.mask;
+ setb |= (mbrdiv << spi->cfg->regs->br.shift) & spi->cfg->regs->br.mask;

writel_relaxed((readl_relaxed(spi->base + spi->cfg->regs->br.reg) &
~clrb) | setb,
@@ -1503,8 +1491,7 @@ static int stm32h7_spi_set_mode(struct stm32_spi *spi, unsigned int comm_type)
}

cfg2_clrb |= STM32H7_SPI_CFG2_COMM;
- cfg2_setb |= (mode << STM32H7_SPI_CFG2_COMM_SHIFT) &
- STM32H7_SPI_CFG2_COMM;
+ cfg2_setb |= FIELD_PREP(STM32H7_SPI_CFG2_COMM, mode);

writel_relaxed(
(readl_relaxed(spi->base + STM32H7_SPI_CFG2) &
@@ -1527,14 +1514,15 @@ static void stm32h7_spi_data_idleness(struct stm32_spi *spi, u32 len)
cfg2_clrb |= STM32H7_SPI_CFG2_MIDI;
if ((len > 1) && (spi->cur_midi > 0)) {
u32 sck_period_ns = DIV_ROUND_UP(SPI_1HZ_NS, spi->cur_speed);
- u32 midi = min((u32)DIV_ROUND_UP(spi->cur_midi, sck_period_ns),
- (u32)STM32H7_SPI_CFG2_MIDI >>
- STM32H7_SPI_CFG2_MIDI_SHIFT);
+ u32 midi = min_t(u32,
+ DIV_ROUND_UP(spi->cur_midi, sck_period_ns),
+ FIELD_GET(STM32H7_SPI_CFG2_MIDI,
+ STM32H7_SPI_CFG2_MIDI));
+

dev_dbg(spi->dev, "period=%dns, midi=%d(=%dns)\n",
sck_period_ns, midi, midi * sck_period_ns);
- cfg2_setb |= (midi << STM32H7_SPI_CFG2_MIDI_SHIFT) &
- STM32H7_SPI_CFG2_MIDI;
+ cfg2_setb |= FIELD_PREP(STM32H7_SPI_CFG2_MIDI, midi);
}

writel_relaxed((readl_relaxed(spi->base + STM32H7_SPI_CFG2) &
@@ -1549,14 +1537,8 @@ static void stm32h7_spi_data_idleness(struct stm32_spi *spi, u32 len)
*/
static int stm32h7_spi_number_of_data(struct stm32_spi *spi, u32 nb_words)
{
- u32 cr2_clrb = 0, cr2_setb = 0;
-
- if (nb_words <= (STM32H7_SPI_CR2_TSIZE >>
- STM32H7_SPI_CR2_TSIZE_SHIFT)) {
- cr2_clrb |= STM32H7_SPI_CR2_TSIZE;
- cr2_setb = nb_words << STM32H7_SPI_CR2_TSIZE_SHIFT;
- writel_relaxed((readl_relaxed(spi->base + STM32H7_SPI_CR2) &
- ~cr2_clrb) | cr2_setb,
+ if (nb_words <= STM32H7_SPI_TSIZE_MAX) {
+ writel_relaxed(FIELD_PREP(STM32H7_SPI_CR2_TSIZE, nb_words),
spi->base + STM32H7_SPI_CR2);
} else {
return -EMSGSIZE;
--
2.17.1