On Tue, Sep 26, 2017 at 6:40 PM, Eugeniy Paltsev <eugeniy.palt...@synopsys.com> wrote: > Add option to set spi controller clock frequency via device tree > using standard clock bindings. > Old way of setting spi controller clock frequency (via implementation > of 'cm_get_spi_controller_clk_hz' function in platform specific code) > remains supported. > > Signed-off-by: Eugeniy Paltsev <eugeniy.palt...@synopsys.com> > --- > Resending due to previously sent one was discarded by mailing list. > > drivers/spi/designware_spi.c | 68 > +++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 67 insertions(+), 1 deletion(-) > > diff --git a/drivers/spi/designware_spi.c b/drivers/spi/designware_spi.c > index 5aa507b..c70697e 100644 > --- a/drivers/spi/designware_spi.c > +++ b/drivers/spi/designware_spi.c > @@ -11,6 +11,7 @@ > */ > > #include <common.h> > +#include <clk.h> > #include <dm.h> > #include <errno.h> > #include <malloc.h> > @@ -94,6 +95,7 @@ struct dw_spi_priv { > void __iomem *regs; > unsigned int freq; /* Default frequency */ > unsigned int mode; > + unsigned long bus_clk_rate; > > int bits_per_word; > u8 cs; /* chip select pin */ > @@ -176,14 +178,78 @@ static void spi_hw_init(struct dw_spi_priv *priv) > debug("%s: fifo_len=%d\n", __func__, priv->fifo_len); > } > > +/* > + * cm_get_spi_controller_clk_hz function is old way to set spi controller > + * frequency. If it isn't implemented and spi controller frequency isn't set > via > + * device tree we will get into next default function. > + */ > +__weak unsigned int cm_get_spi_controller_clk_hz(void) > +{ > + error("SPI clock is defined neither via device tree nor via > cm_get_spi_controller_clk_hz!"); > + > + return 0; > +} > + > +static int dw_spi_of_get_clk(struct udevice *bus) > +{ > +#if CONFIG_IS_ENABLED(OF_CONTROL) && CONFIG_IS_ENABLED(CLK) > + struct dw_spi_priv *priv = dev_get_priv(bus); > + unsigned long clk_rate; > + struct clk clk; > + int ret; > + > + ret = clk_get_by_index(bus, 0, &clk); > + if (ret) > + return -EINVAL; > + > + ret = clk_enable(&clk); > + if (ret && ret != -ENOSYS) > + return ret; > + > + clk_rate = clk_get_rate(&clk); > + if (!clk_rate) > + return -EINVAL;
Use bus_clk_rate instead of local clk_rate and disable the clk if it can't get the rate. > + > + priv->bus_clk_rate = clk_rate; > + > + clk_free(&clk); > + > + return 0; > +#endif > + > + return -ENOSYS; > +} > + > +static int dw_spi_get_clk(struct udevice *bus) > +{ > + struct dw_spi_priv *priv = dev_get_priv(bus); > + > + /* Firstly try to get clock frequency from device tree */ > + if (!dw_spi_of_get_clk(bus)) > + return 0; > + > + /* In case of failure rollback to cm_get_spi_controller_clk_hz */ > + priv->bus_clk_rate = cm_get_spi_controller_clk_hz(); Why weak function, we can just return with error message since weak does the same job thanks! -- Jagan Teki Free Software Engineer | www.openedev.com U-Boot, Linux | Upstream Maintainer Hyderabad, India. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot