spi: zynq_spi: Use clk subsystem to get reference spi clk

Remove fixed reference clk used by plat->frequency and use clk
subsystem to get reference clk. As per spi dt bindings
"spi-max-frequency" property should be used by the slave devices.
This property is read by spi-uclass driver for the slave device.
So avoid reading above property from the platform driver.

Signed-off-by: T Karthik Reddy <t.karthik.reddy@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

diff --git a/drivers/spi/zynq_spi.c b/drivers/spi/zynq_spi.c
index 9923931..cb911c3 100644 (file)
--- a/drivers/spi/zynq_spi.c
+++ b/drivers/spi/zynq_spi.c
@@ -8,10 +8,12 @@
 
 #include <common.h>
 #include <dm.h>
+#include <dm/device_compat.h>
 #include <log.h>
 #include <malloc.h>
 #include <spi.h>
 #include <time.h>
+#include <clk.h>
 #include <asm/io.h>
 #include <linux/bitops.h>
 #include <linux/delay.h>
@@ -79,17 +81,10 @@ static int zynq_spi_ofdata_to_platdata(struct udevice *bus)
 
        plat->regs = dev_read_addr_ptr(bus);
 
-       /* FIXME: Use 250MHz as a suitable default */
-       plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency",
-                                       250000000);
        plat->deactivate_delay_us = fdtdec_get_int(blob, node,
                                        "spi-deactivate-delay", 0);
        plat->activate_delay_us = fdtdec_get_int(blob, node,
                                                 "spi-activate-delay", 0);
-       plat->speed_hz = plat->frequency / 2;
-
-       debug("%s: regs=%p max-frequency=%d\n", __func__,
-             plat->regs, plat->frequency);
 
        return 0;
 }
@@ -128,13 +123,39 @@ static int zynq_spi_probe(struct udevice *bus)
 {
        struct zynq_spi_platdata *plat = dev_get_platdata(bus);
        struct zynq_spi_priv *priv = dev_get_priv(bus);
+       struct clk clk;
+       unsigned long clock;
+       int ret;
 
        priv->regs = plat->regs;
        priv->fifo_depth = ZYNQ_SPI_FIFO_DEPTH;
 
+       ret = clk_get_by_name(bus, "ref_clk", &clk);
+       if (ret < 0) {
+               dev_err(bus, "failed to get clock\n");
+               return ret;
+       }
+
+       clock = clk_get_rate(&clk);
+       if (IS_ERR_VALUE(clock)) {
+               dev_err(bus, "failed to get rate\n");
+               return clock;
+       }
+
+       ret = clk_enable(&clk);
+       if (ret && ret != -ENOSYS) {
+               dev_err(bus, "failed to enable clock\n");
+               return ret;
+       }
+
        /* init the zynq spi hw */
        zynq_spi_init_hw(priv);
 
+       plat->frequency = clock;
+       plat->speed_hz = plat->frequency / 2;
+
+       debug("%s: max-frequency=%d\n", __func__, plat->speed_hz);
+
        return 0;
 }