From: David Lechner <dlechner@baylibre.com>
To: Mark Brown <broonie@kernel.org>
Cc: "David Lechner" <dlechner@baylibre.com>,
"Michael Hennerich" <michael.hennerich@analog.com>,
"Nuno Sá" <nuno.sa@analog.com>,
linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] spi: axi-spi-engine: Add SPI_CS_HIGH support
Date: Wed, 8 May 2024 11:06:53 -0500 [thread overview]
Message-ID: <20240508-spi-axi-spi-engine-add-spi_cs_high-support-v1-1-695dd8e45f00@baylibre.com> (raw)
The AXI SPI Engine IP core v1.2 added support for SPI_CS_HIGH. This
provides the driver implementation to make use of this feature when
supported hardware is detected.
Signed-off-by: David Lechner <dlechner@baylibre.com>
---
drivers/spi/spi-axi-spi-engine.c | 34 ++++++++++++++++++++++++++++++++++
1 file changed, 34 insertions(+)
diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index e358ac5b4509..3231f67ae265 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c
@@ -46,6 +46,7 @@
#define SPI_ENGINE_INST_ASSERT 0x1
#define SPI_ENGINE_INST_WRITE 0x2
#define SPI_ENGINE_INST_MISC 0x3
+#define SPI_ENGINE_INST_CS_INV 0x4
#define SPI_ENGINE_CMD_REG_CLK_DIV 0x0
#define SPI_ENGINE_CMD_REG_CONFIG 0x1
@@ -73,6 +74,8 @@
SPI_ENGINE_CMD(SPI_ENGINE_INST_MISC, SPI_ENGINE_MISC_SLEEP, (delay))
#define SPI_ENGINE_CMD_SYNC(id) \
SPI_ENGINE_CMD(SPI_ENGINE_INST_MISC, SPI_ENGINE_MISC_SYNC, (id))
+#define SPI_ENGINE_CMD_CS_INV(flags) \
+ SPI_ENGINE_CMD(SPI_ENGINE_INST_CS_INV, 0, (flags))
struct spi_engine_program {
unsigned int length;
@@ -111,6 +114,8 @@ struct spi_engine {
struct spi_engine_message_state msg_state;
struct completion msg_complete;
unsigned int int_enable;
+ /* shadows hardware CS inversion flag state */
+ u8 cs_inv;
};
static void spi_engine_program_add_cmd(struct spi_engine_program *p,
@@ -530,6 +535,29 @@ static int spi_engine_unoptimize_message(struct spi_message *msg)
return 0;
}
+static int spi_engine_setup(struct spi_device *device)
+{
+ struct spi_controller *host = device->controller;
+ struct spi_engine *spi_engine = spi_controller_get_devdata(host);
+
+ if (device->mode & SPI_CS_HIGH)
+ spi_engine->cs_inv |= BIT(spi_get_chipselect(device, 0));
+ else
+ spi_engine->cs_inv &= ~BIT(spi_get_chipselect(device, 0));
+
+ writel_relaxed(SPI_ENGINE_CMD_CS_INV(spi_engine->cs_inv),
+ spi_engine->base + SPI_ENGINE_REG_CMD_FIFO);
+
+ /*
+ * In addition to setting the flags, we have to do a CS assert command
+ * to make the new setting actually take effect.
+ */
+ writel_relaxed(SPI_ENGINE_CMD_ASSERT(0, 0xff),
+ spi_engine->base + SPI_ENGINE_REG_CMD_FIFO);
+
+ return 0;
+}
+
static int spi_engine_transfer_one_message(struct spi_controller *host,
struct spi_message *msg)
{
@@ -653,6 +681,12 @@ static int spi_engine_probe(struct platform_device *pdev)
host->unoptimize_message = spi_engine_unoptimize_message;
host->num_chipselect = 8;
+ /* Some features depend of the IP core version. */
+ if (ADI_AXI_PCORE_VER_MINOR(version) >= 2) {
+ host->mode_bits |= SPI_CS_HIGH;
+ host->setup = spi_engine_setup;
+ }
+
if (host->max_speed_hz == 0)
return dev_err_probe(&pdev->dev, -EINVAL, "spi_clk rate is 0");
---
base-commit: a2890dc5d13c377f54c21010c040ed092fcf99c4
change-id: 20240508-spi-axi-spi-engine-add-spi_cs_high-support-d1aa542e9530
reply other threads:[~2024-05-08 16:07 UTC|newest]
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