shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-06-09 12:17:12 +09:00
Code Issues Packages Projects Releases Wiki Activity

spi: rockchip: set higher io driver when sclk higher than 24MHz

Browse Source 
Change-Id: I963c92eab7f7bff0b32e2ac262aa79f0667f39ee
Signed-off-by: Huibin Hong <huibin.hong@rock-chips.com>
This commit is contained in:
Huibin Hong
2018-02-24 20:57:22 +08:00
committed by Tao Huang
parent 787343f9d7
commit 7e4349ec9d
1 changed files with 23 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

23
drivers/spi/spi-rockchip.c
View File

@@ -141,6 +141,8 @@
/* sclk_out: spi master internal logic in rk3x can support 50Mhz */
#define MAX_SCLK_OUT 50000000
/* max sclk of driver strength 4mA */
#define IO_DRIVER_4MA_MAX_SCLK_OUT 24000000
enum rockchip_ssi_type {
SSI_MOTO_SPI = 0,
@@ -191,6 +193,7 @@ struct rockchip_spi {
struct sg_table rx_sg;
struct rockchip_spi_dma_data dma_rx;
struct rockchip_spi_dma_data dma_tx;
struct pinctrl_state *high_speed_state;
};
static inline void spi_enable_chip(struct rockchip_spi *rs, int enable)
@@ -537,6 +540,19 @@ static void rockchip_spi_config(struct rockchip_spi *rs)
div = DIV_ROUND_UP(rs->max_freq, rs->speed);
div = (div + 1) & 0xfffe;
/*
* If speed is larger than IO_DRIVER_4MA_MAX_SCLK_OUT,
* set higher driver strength.
*/
if (rs->high_speed_state) {
if (rs->speed > IO_DRIVER_4MA_MAX_SCLK_OUT)
pinctrl_select_state(rs->dev->pins->p,
rs->high_speed_state);
else
pinctrl_select_state(rs->dev->pins->p,
rs->dev->pins->default_state);
}
/* Rx sample delay is expressed in parent clock cycles (max 3) */
rsd = DIV_ROUND_CLOSEST(rs->rsd_nsecs * (rs->max_freq >> 8),
1000000000 >> 8);
@@ -759,6 +775,13 @@ static int rockchip_spi_probe(struct platform_device *pdev)
master->dma_rx = rs->dma_rx.ch;
}
rs->high_speed_state = pinctrl_lookup_state(rs->dev->pins->p,
"high_speed");
if (IS_ERR_OR_NULL(rs->high_speed_state))
dev_warn(&pdev->dev, "no high_speed pinctrl state\n");
else
rs->high_speed_state = NULL;
ret = devm_spi_register_master(&pdev->dev, master);
if (ret) {
dev_err(&pdev->dev, "Failed to register master\n");