Add support to parse and setup the common OF CS delay properties. The
parsing is quite confusing since the kernel driver API decided to use a
u16 for the value. I kept it this way to be closer to the Linux code.
This prepares the core for the upcoming core based message handling.
Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
---
drivers/spi/spi.c | 25 +++++++++++++++++++++++++
include/spi/spi.h | 22 ++++++++++++++++++++++
2 files changed, 47 insertions(+)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index c239de9d8549..e8a0b1b84be5 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -70,6 +70,9 @@ struct spi_device *spi_new_device(struct spi_controller *ctrl,
proxy->cs_gpiod = ctrl->cs_gpiods[chip->chip_select];
proxy->max_speed_hz = chip->max_speed_hz;
proxy->mode = chip->mode;
+ proxy->cs_setup = chip->cs_setup;
+ proxy->cs_hold = chip->cs_hold;
+ proxy->cs_inactive = chip->cs_inactive;
proxy->bits_per_word = chip->bits_per_word ? chip->bits_per_word : 8;
proxy->dev.platform_data = chip->platform_data;
proxy->dev.bus = &spi_bus;
@@ -111,6 +114,22 @@ struct spi_device *spi_new_device(struct spi_controller *ctrl,
}
EXPORT_SYMBOL(spi_new_device);
+static void of_spi_parse_dt_cs_delay(struct device_node *nc,
+ struct spi_delay *delay, const char *prop)
+{
+ u32 value;
+
+ if (!of_property_read_u32(nc, prop, &value)) {
+ if (value > U16_MAX) {
+ delay->value = DIV_ROUND_UP(value, 1000);
+ delay->unit = SPI_DELAY_UNIT_USECS;
+ } else {
+ delay->value = value;
+ delay->unit = SPI_DELAY_UNIT_NSECS;
+ }
+ }
+}
+
static void spi_of_register_slaves(struct spi_controller *ctrl)
{
struct device_node *n;
@@ -145,6 +164,12 @@ static void spi_of_register_slaves(struct spi_controller *ctrl)
chip.mode |= SPI_3WIRE;
of_property_read_u32(n, "spi-max-frequency",
&chip.max_speed_hz);
+
+ /* Device CS delays */
+ of_spi_parse_dt_cs_delay(n, &chip.cs_setup, "spi-cs-setup-delay-ns");
+ of_spi_parse_dt_cs_delay(n, &chip.cs_hold, "spi-cs-hold-delay-ns");
+ of_spi_parse_dt_cs_delay(n, &chip.cs_inactive, "spi-cs-inactive-delay-ns");
+
reg = of_find_property(n, "reg", NULL);
if (!reg)
continue;
diff --git a/include/spi/spi.h b/include/spi/spi.h
index 53d6bd32e025..8363e73c6754 100644
--- a/include/spi/spi.h
+++ b/include/spi/spi.h
@@ -13,6 +13,19 @@
struct spi_controller_mem_ops;
struct spi_message;
+/**
+ * struct spi_delay - SPI delay information
+ * @value: Value for the delay
+ * @unit: Unit for the delay
+ */
+struct spi_delay {
+#define SPI_DELAY_UNIT_USECS 0
+#define SPI_DELAY_UNIT_NSECS 1
+#define SPI_DELAY_UNIT_SCK 2
+ u16 value;
+ u8 unit;
+};
+
struct spi_board_info {
char *name;
int max_speed_hz;
@@ -26,6 +39,11 @@ struct spi_board_info {
u8 bits_per_word;
void *platform_data;
struct device_node *device_node;
+
+ /* CS delays */
+ struct spi_delay cs_setup;
+ struct spi_delay cs_hold;
+ struct spi_delay cs_inactive;
};
/**
@@ -101,6 +119,10 @@ struct spi_device {
void *controller_data;
const char *modalias;
struct gpio_desc *cs_gpiod; /* Chip select gpio desc */
+ /* CS delays */
+ struct spi_delay cs_setup;
+ struct spi_delay cs_hold;
+ struct spi_delay cs_inactive;
/*
* likely need more hooks for more protocol options affecting how
--
2.39.5
