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path: root/drivers/spi/spi-stm32.c
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Diffstat (limited to 'drivers/spi/spi-stm32.c')
-rw-r--r--drivers/spi/spi-stm32.c150
1 files changed, 60 insertions, 90 deletions
diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index 6017209c6d2f..25c076461011 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@st.com> 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)
@@ -167,8 +162,6 @@
#define SPI_3WIRE_TX 3
#define SPI_3WIRE_RX 4
-#define SPI_1HZ_NS 1000000000
-
/*
* use PIO for small transfers, avoiding DMA setup/teardown overhead for drivers
* without fifo buffers.
@@ -268,7 +261,6 @@ struct stm32_spi_cfg {
* @base: virtual memory area
* @clk: hw kernel clock feeding the SPI clock generator
* @clk_rate: rate of the hw kernel clock feeding the SPI clock generator
- * @rst: SPI controller reset line
* @lock: prevent I/O concurrent access
* @irq: SPI controller interrupt line
* @fifo_size: size of the embedded fifo in bytes
@@ -294,7 +286,6 @@ struct stm32_spi {
void __iomem *base;
struct clk *clk;
u32 clk_rate;
- struct reset_control *rst;
spinlock_t lock; /* prevent I/O concurrent access */
int irq;
unsigned int fifo_size;
@@ -417,9 +408,7 @@ 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);
@@ -473,34 +462,14 @@ static int stm32_spi_prepare_mbr(struct stm32_spi *spi, u32 speed_hz,
*/
static u32 stm32h7_spi_prepare_fthlv(struct stm32_spi *spi, u32 xfer_len)
{
- u32 fthlv, half_fifo, packet;
+ u32 packet, bpw;
/* data packet should not exceed 1/2 of fifo space */
- half_fifo = (spi->fifo_size / 2);
-
- /* data_packet should not exceed transfer length */
- if (half_fifo > xfer_len)
- packet = xfer_len;
- else
- packet = half_fifo;
-
- if (spi->cur_bpw <= 8)
- fthlv = packet;
- else if (spi->cur_bpw <= 16)
- fthlv = packet / 2;
- else
- fthlv = packet / 4;
+ packet = clamp(xfer_len, 1U, spi->fifo_size / 2);
/* align packet size with data registers access */
- if (spi->cur_bpw > 8)
- fthlv += (fthlv % 2) ? 1 : 0;
- else
- fthlv += (fthlv % 4) ? (4 - (fthlv % 4)) : 0;
-
- if (!fthlv)
- fthlv = 1;
-
- return fthlv;
+ bpw = DIV_ROUND_UP(spi->cur_bpw, 8);
+ return DIV_ROUND_UP(packet, bpw);
}
/**
@@ -607,8 +576,7 @@ 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) ||
@@ -635,8 +603,7 @@ 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__,
@@ -928,8 +895,8 @@ static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id)
mask |= STM32H7_SPI_SR_RXP;
if (!(sr & mask)) {
- dev_dbg(spi->dev, "spurious IT (sr=0x%08x, ier=0x%08x)\n",
- sr, ier);
+ dev_warn(spi->dev, "spurious IT (sr=0x%08x, ier=0x%08x)\n",
+ sr, ier);
spin_unlock_irqrestore(&spi->lock, flags);
return IRQ_NONE;
}
@@ -956,15 +923,8 @@ static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id)
}
if (sr & STM32H7_SPI_SR_OVR) {
- dev_warn(spi->dev, "Overrun: received value discarded\n");
- if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
- stm32h7_spi_read_rxfifo(spi, false);
- /*
- * If overrun is detected while using DMA, it means that
- * something went wrong, so stop the current transfer
- */
- if (spi->cur_usedma)
- end = true;
+ dev_err(spi->dev, "Overrun: RX data lost\n");
+ end = true;
}
if (sr & STM32H7_SPI_SR_EOT) {
@@ -1028,10 +988,24 @@ static int stm32_spi_prepare_msg(struct spi_master *master,
clrb |= spi->cfg->regs->lsb_first.mask;
dev_dbg(spi->dev, "cpol=%d cpha=%d lsb_first=%d cs_high=%d\n",
- spi_dev->mode & SPI_CPOL,
- spi_dev->mode & SPI_CPHA,
- spi_dev->mode & SPI_LSB_FIRST,
- spi_dev->mode & SPI_CS_HIGH);
+ !!(spi_dev->mode & SPI_CPOL),
+ !!(spi_dev->mode & SPI_CPHA),
+ !!(spi_dev->mode & SPI_LSB_FIRST),
+ !!(spi_dev->mode & SPI_CS_HIGH));
+
+ /* On STM32H7, messages should not exceed a maximum size setted
+ * afterward via the set_number_of_data function. In order to
+ * ensure that, split large messages into several messages
+ */
+ if (spi->cfg->set_number_of_data) {
+ int ret;
+
+ ret = spi_split_transfers_maxsize(master, msg,
+ STM32H7_SPI_TSIZE_MAX,
+ GFP_KERNEL | GFP_DMA);
+ if (ret)
+ return ret;
+ }
spin_lock_irqsave(&spi->lock, flags);
@@ -1405,15 +1379,13 @@ 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) &
@@ -1431,8 +1403,7 @@ 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,
@@ -1523,8 +1494,7 @@ 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) &
@@ -1546,15 +1516,16 @@ 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 sck_period_ns = DIV_ROUND_UP(NSEC_PER_SEC, spi->cur_speed);
+ 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) &
@@ -1569,14 +1540,8 @@ 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;
@@ -1677,6 +1642,10 @@ static int stm32_spi_transfer_one(struct spi_master *master,
struct stm32_spi *spi = spi_master_get_devdata(master);
int ret;
+ /* Don't do anything on 0 bytes transfers */
+ if (transfer->len == 0)
+ return 0;
+
spi->tx_buf = transfer->tx_buf;
spi->rx_buf = transfer->rx_buf;
spi->tx_len = spi->tx_buf ? transfer->len : 0;
@@ -1831,6 +1800,7 @@ static int stm32_spi_probe(struct platform_device *pdev)
struct spi_master *master;
struct stm32_spi *spi;
struct resource *res;
+ struct reset_control *rst;
int ret;
master = spi_alloc_master(&pdev->dev, sizeof(struct stm32_spi));
@@ -1892,11 +1862,17 @@ static int stm32_spi_probe(struct platform_device *pdev)
goto err_clk_disable;
}
- spi->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
- if (!IS_ERR(spi->rst)) {
- reset_control_assert(spi->rst);
+ rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
+ if (rst) {
+ if (IS_ERR(rst)) {
+ ret = dev_err_probe(&pdev->dev, PTR_ERR(rst),
+ "failed to get reset\n");
+ goto err_clk_disable;
+ }
+
+ reset_control_assert(rst);
udelay(2);
- reset_control_deassert(spi->rst);
+ reset_control_deassert(rst);
}
if (spi->cfg->has_fifo)
@@ -1960,12 +1936,6 @@ static int stm32_spi_probe(struct platform_device *pdev)
goto err_pm_disable;
}
- if (!master->cs_gpiods) {
- dev_err(&pdev->dev, "no CS gpios available\n");
- ret = -EINVAL;
- goto err_pm_disable;
- }
-
dev_info(&pdev->dev, "driver initialized\n");
return 0;
generated by cgit v1.2.3 (git 2.39.0) at 2025-02-05 10:56:56 +0300