[PATCH 3/6] spi: stm32: add st,stm32mp25-spi compatible supporting STM32MP25 soc

From: Alain Volmat
Date: Mon Dec 18 2023 - 10:59:29 EST

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Previous message: Alain Volmat: "[PATCH 1/6] spi: stm32: use dma_get_slave_caps prior to configuring dma channel"
In reply to: Alain Volmat: "[PATCH 1/6] spi: stm32: use dma_get_slave_caps prior to configuring dma channel"
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From: Valentin Caron <valentin.caron@xxxxxxxxxxx>

Add support for the STM32MP25:
- Burst should not be enabled with the new DMA used on STM32MP25.
- STM32MP25 SPI8 has a limited feature set, it can only send words of
8 or 16 bits and with a maximum words number of 1024.

Signed-off-by: Valentin Caron <valentin.caron@xxxxxxxxxxx>
Signed-off-by: Alain Volmat <alain.volmat@xxxxxxxxxxx>
---
drivers/spi/spi-stm32.c | 132 ++++++++++++++++++++++++++++++++++++----
1 file changed, 120 insertions(+), 12 deletions(-)

diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index af0c27d8d704..e61302ef3c21 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -154,6 +154,20 @@
/* STM32H7_SPI_I2SCFGR bit fields */
#define STM32H7_SPI_I2SCFGR_I2SMOD BIT(0)

+/* STM32MP25 SPI registers bit fields */
+#define STM32MP25_SPI_HWCFGR1 0x3F0
+
+/* STM32MP25_SPI_CR2 bit fields */
+#define STM32MP25_SPI_TSIZE_MAX_LIMITED GENMASK(9, 0)
+
+/* STM32MP25_SPI_HWCFGR1 */
+#define STM32MP25_SPI_HWCFGR1_FULLCFG GENMASK(27, 24)
+#define STM32MP25_SPI_HWCFGR1_FULLCFG_LIMITED 0x0
+#define STM32MP25_SPI_HWCFGR1_FULLCFG_FULL 0x1
+#define STM32MP25_SPI_HWCFGR1_DSCFG GENMASK(19, 16)
+#define STM32MP25_SPI_HWCFGR1_DSCFG_16_B 0x0
+#define STM32MP25_SPI_HWCFGR1_DSCFG_32_B 0x1
+
/* STM32H7 SPI Master Baud Rate min/max divisor */
#define STM32H7_SPI_MBR_DIV_MIN (2 << STM32H7_SPI_CFG1_MBR_MIN)
#define STM32H7_SPI_MBR_DIV_MAX (2 << STM32H7_SPI_CFG1_MBR_MAX)
@@ -207,6 +221,7 @@ struct stm32_spi_reg {
* @br: baud rate register and bitfields
* @rx: SPI RX data register
* @tx: SPI TX data register
+ * @fullcfg: SPI full or limited feature set register
*/
struct stm32_spi_regspec {
const struct stm32_spi_reg en;
@@ -219,6 +234,7 @@ struct stm32_spi_regspec {
const struct stm32_spi_reg br;
const struct stm32_spi_reg rx;
const struct stm32_spi_reg tx;
+ const struct stm32_spi_reg fullcfg;
};

struct stm32_spi;
@@ -250,6 +266,7 @@ struct stm32_spi;
* @has_fifo: boolean to know if fifo is used for driver
* @has_device_mode: is this compatible capable to switch on device mode
* @flags: compatible specific SPI controller flags used at registration time
+ * @prevent_dma_burst: boolean to indicate to prevent DMA burst
*/
struct stm32_spi_cfg {
const struct stm32_spi_regspec *regs;
@@ -274,6 +291,7 @@ struct stm32_spi_cfg {
bool has_fifo;
bool has_device_mode;
u16 flags;
+ bool prevent_dma_burst;
};

/**
@@ -287,6 +305,8 @@ struct stm32_spi_cfg {
* @lock: prevent I/O concurrent access
* @irq: SPI controller interrupt line
* @fifo_size: size of the embedded fifo in bytes
+ * @t_size_max: maximum number of data of one transfer
+ * @feature_set: SPI full or limited feature set
* @cur_midi: host inter-data idleness in ns
* @cur_speed: speed configured in Hz
* @cur_half_period: time of a half bit in us
@@ -314,6 +334,10 @@ struct stm32_spi {
spinlock_t lock; /* prevent I/O concurrent access */
int irq;
unsigned int fifo_size;
+ unsigned int t_size_max;
+ unsigned int feature_set;
+#define STM32_SPI_FEATURE_LIMITED STM32MP25_SPI_HWCFGR1_FULLCFG_LIMITED /* 0x0 */
+#define STM32_SPI_FEATURE_FULL STM32MP25_SPI_HWCFGR1_FULLCFG_FULL /* 0x1 */

unsigned int cur_midi;
unsigned int cur_speed;
@@ -371,6 +395,28 @@ static const struct stm32_spi_regspec stm32h7_spi_regspec = {
.tx = { STM32H7_SPI_TXDR },
};

+static const struct stm32_spi_regspec stm32mp25_spi_regspec = {
+ /* SPI data transfer is enabled but spi_ker_ck is idle.
+ * CFG1 and CFG2 registers are write protected when SPE is enabled.
+ */
+ .en = { STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE },
+
+ .dma_rx_en = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_RXDMAEN },
+ .dma_tx_en = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_TXDMAEN },
+
+ .cpol = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_CPOL },
+ .cpha = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_CPHA },
+ .lsb_first = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_LSBFRST },
+ .cs_high = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_SSIOP },
+ .br = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_MBR,
+ STM32H7_SPI_CFG1_MBR_SHIFT },
+
+ .rx = { STM32H7_SPI_RXDR },
+ .tx = { STM32H7_SPI_TXDR },
+
+ .fullcfg = { STM32MP25_SPI_HWCFGR1, STM32MP25_SPI_HWCFGR1_FULLCFG },
+};
+
static inline void stm32_spi_set_bits(struct stm32_spi *spi,
u32 offset, u32 bits)
{
@@ -457,6 +503,28 @@ static int stm32h7_spi_get_bpw_mask(struct stm32_spi *spi)
return SPI_BPW_RANGE_MASK(4, max_bpw);
}

+/**
+ * stm32mp25_spi_get_bpw_mask - Return bits per word mask
+ * @spi: pointer to the spi controller data structure
+ */
+static int stm32mp25_spi_get_bpw_mask(struct stm32_spi *spi)
+{
+ u32 dscfg, max_bpw;
+
+ if (spi->feature_set == STM32_SPI_FEATURE_LIMITED) {
+ dev_dbg(spi->dev, "8-bit or 16-bit data frame supported\n");
+ return SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
+ }
+
+ dscfg = FIELD_GET(STM32MP25_SPI_HWCFGR1_DSCFG,
+ readl_relaxed(spi->base + STM32MP25_SPI_HWCFGR1));
+ max_bpw = 16;
+ if (dscfg == STM32MP25_SPI_HWCFGR1_DSCFG_32_B)
+ max_bpw = 32;
+ dev_dbg(spi->dev, "%d-bit maximum data frame\n", max_bpw);
+ return SPI_BPW_RANGE_MASK(4, max_bpw);
+}
+
/**
* stm32_spi_prepare_mbr - Determine baud rate divisor value
* @spi: pointer to the spi controller data structure
@@ -1103,7 +1171,7 @@ static int stm32_spi_prepare_msg(struct spi_controller *ctrl,
int ret;

ret = spi_split_transfers_maxwords(ctrl, msg,
- STM32H7_SPI_TSIZE_MAX,
+ spi->t_size_max,
GFP_KERNEL | GFP_DMA);
if (ret)
return ret;
@@ -1168,7 +1236,7 @@ static void stm32_spi_dma_config(struct stm32_spi *spi,
{
enum dma_slave_buswidth buswidth;
struct dma_slave_caps caps;
- u32 maxburst;
+ u32 maxburst = 1;
int ret;

if (spi->cur_bpw <= 8)
@@ -1178,15 +1246,9 @@ static void stm32_spi_dma_config(struct stm32_spi *spi,
else
buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;

- if (spi->cfg->has_fifo) {
- /* Valid for DMA Half or Full Fifo threshold */
- if (spi->cur_fthlv == 2)
- maxburst = 1;
- else
- maxburst = spi->cur_fthlv;
- } else {
- maxburst = 1;
- }
+ /* Valid for DMA Half or Full Fifo threshold */
+ if (!spi->cfg->prevent_dma_burst && spi->cfg->has_fifo && spi->cur_fthlv != 2)
+ maxburst = spi->cur_fthlv;

/* Get the DMA channel caps, and adjust maxburst if possible */
ret = dma_get_slave_caps(dma_chan, &caps);
@@ -1671,7 +1733,7 @@ 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)
{
- if (nb_words <= STM32H7_SPI_TSIZE_MAX) {
+ if (nb_words <= spi->t_size_max) {
writel_relaxed(FIELD_PREP(STM32H7_SPI_CR2_TSIZE, nb_words),
spi->base + STM32H7_SPI_CR2);
} else {
@@ -1954,7 +2016,37 @@ static const struct stm32_spi_cfg stm32h7_spi_cfg = {
.has_device_mode = true,
};

+/*
+ * STM32MP2 is compatible with the STM32H7 except:
+ * - enforce the DMA maxburst value to 1
+ * - spi8 have limited feature set (TSIZE_MAX = 1024, BPW of 8 OR 16)
+ */
+static const struct stm32_spi_cfg stm32mp25_spi_cfg = {
+ .regs = &stm32mp25_spi_regspec,
+ .get_fifo_size = stm32h7_spi_get_fifo_size,
+ .get_bpw_mask = stm32mp25_spi_get_bpw_mask,
+ .disable = stm32h7_spi_disable,
+ .config = stm32h7_spi_config,
+ .set_bpw = stm32h7_spi_set_bpw,
+ .set_mode = stm32h7_spi_set_mode,
+ .set_data_idleness = stm32h7_spi_data_idleness,
+ .set_number_of_data = stm32h7_spi_number_of_data,
+ .transfer_one_dma_start = stm32h7_spi_transfer_one_dma_start,
+ .dma_rx_cb = stm32_spi_dma_rx_cb,
+ /*
+ * dma_tx_cb is not necessary since in case of TX, dma is followed by
+ * SPI access hence handling is performed within the SPI interrupt
+ */
+ .transfer_one_irq = stm32h7_spi_transfer_one_irq,
+ .irq_handler_thread = stm32h7_spi_irq_thread,
+ .baud_rate_div_min = STM32H7_SPI_MBR_DIV_MIN,
+ .baud_rate_div_max = STM32H7_SPI_MBR_DIV_MAX,
+ .has_fifo = true,
+ .prevent_dma_burst = true,
+};
+
static const struct of_device_id stm32_spi_of_match[] = {
+ { .compatible = "st,stm32mp25-spi", .data = (void *)&stm32mp25_spi_cfg },
{ .compatible = "st,stm32h7-spi", .data = (void *)&stm32h7_spi_cfg },
{ .compatible = "st,stm32f4-spi", .data = (void *)&stm32f4_spi_cfg },
{ .compatible = "st,stm32f7-spi", .data = (void *)&stm32f7_spi_cfg },
@@ -2058,6 +2150,22 @@ static int stm32_spi_probe(struct platform_device *pdev)
if (spi->cfg->has_fifo)
spi->fifo_size = spi->cfg->get_fifo_size(spi);

+ spi->feature_set = STM32_SPI_FEATURE_FULL;
+ if (spi->cfg->regs->fullcfg.reg) {
+ spi->feature_set =
+ FIELD_GET(STM32MP25_SPI_HWCFGR1_FULLCFG,
+ readl_relaxed(spi->base + spi->cfg->regs->fullcfg.reg));
+
+ dev_dbg(spi->dev, "%s feature set\n",
+ spi->feature_set == STM32_SPI_FEATURE_FULL ? "full" : "limited");
+ }
+
+ /* Only for STM32H7 and after */
+ spi->t_size_max = spi->feature_set == STM32_SPI_FEATURE_FULL ?
+ STM32H7_SPI_TSIZE_MAX :
+ STM32MP25_SPI_TSIZE_MAX_LIMITED;
+ dev_dbg(spi->dev, "one message max size %d\n", spi->t_size_max);
+
ret = spi->cfg->config(spi);
if (ret) {
dev_err(&pdev->dev, "controller configuration failed: %d\n",
--
2.25.1

Next message: Stephen Smalley: "Re: [PATCH] SELinux: Introduce security_file_ioctl_compat hook"
Previous message: Alain Volmat: "[PATCH 1/6] spi: stm32: use dma_get_slave_caps prior to configuring dma channel"
In reply to: Alain Volmat: "[PATCH 1/6] spi: stm32: use dma_get_slave_caps prior to configuring dma channel"
Next in thread: Alain Volmat: "[PATCH 4/6] arm64: dts: st: add all 8 spi nodes on stm32mp251"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]