[PATCH 1/3] spi: meson-axg: support MAX 80M clock

From: Yixun Lan
Date: Thu May 03 2018 - 09:39:51 EST


From: Sunny Luo <sunny.luo@xxxxxxxxxxx>

The SPICC controller in Meson-AXG is capable of running at 80M clock.
The ASIC IP is improved and the clock is actually running higher than
previous old SoCs.

Signed-off-by: Sunny Luo <sunny.luo@xxxxxxxxxxx>
Signed-off-by: Yixun Lan <yixun.lan@xxxxxxxxxxx>
---
drivers/spi/spi-meson-spicc.c | 37 +++++++++++++++++++++++++++--------
1 file changed, 29 insertions(+), 8 deletions(-)

diff --git a/drivers/spi/spi-meson-spicc.c b/drivers/spi/spi-meson-spicc.c
index 5c82910e3480..8489f4c9f465 100644
--- a/drivers/spi/spi-meson-spicc.c
+++ b/drivers/spi/spi-meson-spicc.c
@@ -9,11 +9,13 @@

#include <linux/bitfield.h>
#include <linux/clk.h>
+#include <linux/clk-provider.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <linux/types.h>
@@ -34,7 +36,6 @@
* to have a CS go down over the full transfer
*/

-#define SPICC_MAX_FREQ 30000000
#define SPICC_MAX_BURST 128

/* Register Map */
@@ -120,6 +121,10 @@
#define SPICC_BURST_MAX 16
#define SPICC_FIFO_HALF 10

+struct meson_spicc_data {
+ unsigned int max_speed_hz;
+};
+
struct meson_spicc_device {
struct spi_master *master;
struct platform_device *pdev;
@@ -127,6 +132,7 @@ struct meson_spicc_device {
struct clk *core;
struct spi_message *message;
struct spi_transfer *xfer;
+ const struct meson_spicc_data *data;
u8 *tx_buf;
u8 *rx_buf;
unsigned int bytes_per_word;
@@ -517,6 +523,9 @@ static int meson_spicc_probe(struct platform_device *pdev)
spicc->pdev = pdev;
platform_set_drvdata(pdev, spicc);

+ spicc->data = (const struct meson_spicc_data *)
+ of_device_get_match_data(&pdev->dev);
+
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
spicc->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(spicc->base)) {
@@ -567,11 +576,9 @@ static int meson_spicc_probe(struct platform_device *pdev)
master->unprepare_transfer_hardware = meson_spicc_unprepare_transfer;
master->transfer_one = meson_spicc_transfer_one;

- /* Setup max rate according to the Meson GX datasheet */
- if ((rate >> 2) > SPICC_MAX_FREQ)
- master->max_speed_hz = SPICC_MAX_FREQ;
- else
- master->max_speed_hz = rate >> 2;
+ /* Setup max rate according to the Meson datasheet */
+ master->max_speed_hz = min_t(unsigned int, rate >> 1,
+ spicc->data->max_speed_hz);

ret = devm_spi_register_master(&pdev->dev, master);
if (!ret)
@@ -597,9 +604,23 @@ static int meson_spicc_remove(struct platform_device *pdev)
return 0;
}

+static const struct meson_spicc_data meson_spicc_gx_data = {
+ .max_speed_hz = 30000000,
+};
+
+static const struct meson_spicc_data meson_spicc_axg_data = {
+ .max_speed_hz = 80000000,
+};
+
static const struct of_device_id meson_spicc_of_match[] = {
- { .compatible = "amlogic,meson-gx-spicc", },
- { .compatible = "amlogic,meson-axg-spicc", },
+ {
+ .compatible = "amlogic,meson-gx-spicc",
+ .data = &meson_spicc_gx_data,
+ },
+ {
+ .compatible = "amlogic,meson-axg-spicc",
+ .data = &meson_spicc_axg_data,
+ },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, meson_spicc_of_match);
--
2.17.0