[PATCH] spi: mxc_spi: use proper clock for SPI bus

The mxc_get_clock function is around for compatibility with older drivers that are not clock aware. In this case asking for the clk for MXC_CSPI_CLK does not take into account there are multiple SPI busses on modern IMX SoC's and it will return the clock for the first bus which may not be used or configured.
In the case you are not using the first bus you will not get the proper clock. Fix this by obtaining the clock rate from the bus clock.
This resolves an invalid SPI clock frequency configuration for SPI2 on a board where SPI1 is not used.
Signed-off-by: Tim Harvey tharvey@gateworks.com --- drivers/spi/mxc_spi.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c index 9ab39a188b22..2c9b0ada87ba 100644 --- a/drivers/spi/mxc_spi.c +++ b/drivers/spi/mxc_spi.c @@ -114,6 +114,9 @@ struct mxc_spi_slave { u32 ctrl_reg; #if defined(MXC_ECSPI) u32 cfg_reg; +#endif +#if CONFIG_IS_ENABLED(CLK) + struct clk clk; #endif int gpio; int ss_pol; @@ -214,7 +217,11 @@ static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs) #ifdef MXC_ECSPI static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs) { +#if CONFIG_IS_ENABLED(CLK) + u32 clk_src = clk_get_rate(&mxcs->clk); +#else u32 clk_src = mxc_get_clock(MXC_CSPI_CLK); +#endif s32 reg_ctrl, reg_config; u32 ss_pol = 0, sclkpol = 0, sclkpha = 0, sclkctl = 0; u32 pre_div = 0, post_div = 0; @@ -599,14 +606,13 @@ static int mxc_spi_probe(struct udevice *bus) return -ENODEV;
#if CONFIG_IS_ENABLED(CLK) - struct clk clk; - ret = clk_get_by_index(bus, 0, &clk); + ret = clk_get_by_index(bus, 0, &mxcs->clk); if (ret) return ret;
- clk_enable(&clk); + clk_enable(&mxcs->clk);
- mxcs->max_hz = clk_get_rate(&clk); + mxcs->max_hz = clk_get_rate(&mxcs->clk); #else int node = dev_of_offset(bus); const void *blob = gd->fdt_blob;

On Wed, Dec 18, 2024 at 4:42 PM Tim Harvey tharvey@gateworks.com wrote:
The mxc_get_clock function is around for compatibility with older drivers that are not clock aware. In this case asking for the clk for MXC_CSPI_CLK does not take into account there are multiple SPI busses on modern IMX SoC's and it will return the clock for the first bus which may not be used or configured.
In the case you are not using the first bus you will not get the proper clock. Fix this by obtaining the clock rate from the bus clock.
This resolves an invalid SPI clock frequency configuration for SPI2 on a board where SPI1 is not used.
Signed-off-by: Tim Harvey tharvey@gateworks.com
Applied to u-boot-imx/next, thanks.
participants (2)
-
Fabio Estevam
-
Tim Harvey