From: David Lechner <dlechner@baylibre.com>
To: linux-spi@vger.kernel.org
Cc: "David Lechner" <dlechner@baylibre.com>,
"Mark Brown" <broonie@kernel.org>,
"Michael Hennerich" <michael.hennerich@analog.com>,
"Nuno Sá" <nuno.sa@analog.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH 3/9] spi: axi-spi-engine: remove spi_engine_get_clk_div()
Date: Mon, 4 Dec 2023 11:33:29 -0600 [thread overview]
Message-ID: <20231204-axi-spi-engine-series-2-v1-3-063672323fce@baylibre.com> (raw)
In-Reply-To: <20231204-axi-spi-engine-series-2-v1-0-063672323fce@baylibre.com>
Now that host->max_speed_hz and xfer->effective_speed_hz are properly
set, we can use them instead of having to do more complex calculations
to get the clock divider for each transfer.
This removes the spi_engine_get_clk_div() function and replaces it with
just dividing the two clock rates. Since the hardware register value is
the divider minus one, we need to subtract one. Subtracting one was
previously done in the spi_engine_get_clk_div() function.
Signed-off-by: David Lechner <dlechner@baylibre.com>
---
drivers/spi/spi-axi-spi-engine.c | 23 +++++------------------
1 file changed, 5 insertions(+), 18 deletions(-)
diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index ee7b904ae5cf..fa2264d630c3 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c
@@ -140,21 +140,6 @@ static unsigned int spi_engine_get_config(struct spi_device *spi)
return config;
}
-static unsigned int spi_engine_get_clk_div(struct spi_engine *spi_engine,
- struct spi_device *spi, struct spi_transfer *xfer)
-{
- unsigned int clk_div;
-
- clk_div = DIV_ROUND_UP(clk_get_rate(spi_engine->ref_clk),
- xfer->speed_hz * 2);
- if (clk_div > 255)
- clk_div = 255;
- else if (clk_div > 0)
- clk_div -= 1;
-
- return clk_div;
-}
-
static void spi_engine_gen_xfer(struct spi_engine_program *p, bool dry,
struct spi_transfer *xfer)
{
@@ -243,6 +228,7 @@ static void spi_engine_compile_message(struct spi_engine *spi_engine,
struct spi_message *msg, bool dry, struct spi_engine_program *p)
{
struct spi_device *spi = msg->spi;
+ struct spi_controller *host = spi->controller;
struct spi_transfer *xfer;
int clk_div, new_clk_div;
bool keep_cs = false;
@@ -258,12 +244,13 @@ static void spi_engine_compile_message(struct spi_engine *spi_engine,
spi_engine_gen_cs(p, dry, spi, !xfer->cs_off);
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
- new_clk_div = spi_engine_get_clk_div(spi_engine, spi, xfer);
+ new_clk_div = host->max_speed_hz / xfer->effective_speed_hz;
if (new_clk_div != clk_div) {
clk_div = new_clk_div;
+ /* actual divider used is register value + 1 */
spi_engine_program_add_cmd(p, dry,
SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CLK_DIV,
- clk_div));
+ clk_div - 1));
}
if (bits_per_word != xfer->bits_per_word) {
@@ -274,7 +261,7 @@ static void spi_engine_compile_message(struct spi_engine *spi_engine,
}
spi_engine_gen_xfer(p, dry, xfer);
- spi_engine_gen_sleep(p, dry, spi_engine, clk_div, xfer);
+ spi_engine_gen_sleep(p, dry, spi_engine, clk_div - 1, xfer);
if (xfer->cs_change) {
if (list_is_last(&xfer->transfer_list, &msg->transfers)) {
--
2.43.0
next prev parent reply other threads:[~2023-12-04 17:35 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-04 17:33 [PATCH 0/9] spi: axi-spi-engine: improvements round 2 David Lechner
2023-12-04 17:33 ` [PATCH 1/9] spi: axi-spi-engine: return void from spi_engine_compile_message() David Lechner
2023-12-04 17:33 ` [PATCH 2/9] spi: axi-spi-engine: populate xfer->effective_speed_hz David Lechner
2023-12-04 17:33 ` David Lechner [this message]
2023-12-04 17:33 ` [PATCH 4/9] spi: axi-spi-engine: fix sleep ticks calculation David Lechner
2023-12-04 17:33 ` [PATCH 5/9] spi: axi-spi-engine: remove xfer arg from spi_engine_gen_sleep() David Lechner
2023-12-04 17:33 ` [PATCH 6/9] spi: axi-spi-engine: implement xfer->cs_change_delay David Lechner
2023-12-04 17:33 ` [PATCH 7/9] spi: axi-spi-engine: restore clkdiv at end of message David Lechner
2023-12-04 17:33 ` [PATCH 8/9] spi: axi-spi-engine: remove delay from CS assertion David Lechner
2023-12-04 17:33 ` [PATCH 9/9] spi: axi-spi-engine: add watchdog timer David Lechner
2023-12-05 15:12 ` [PATCH 0/9] spi: axi-spi-engine: improvements round 2 Nuno Sá
2023-12-05 15:52 ` Hennerich, Michael
2023-12-06 21:04 ` Mark Brown
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