On Tue, Sep 26, 2017 at 6:40 PM, Eugeniy Paltsev Eugeniy.Paltsev@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.Paltsev@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!