x86: Add a clock driver for Intel devices
So far we have avoided adding a clock driver for Intel devices. But the
Designware I2C driver needs a different clock (133MHz) on Intel devices
than on others (166MHz). Add a simple driver that provides this
information.
This driver can be expanded later as needed.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/clk/intel/clk_intel.c b/drivers/clk/intel/clk_intel.c
new file mode 100644
index 0000000..d2e1549
--- /dev/null
+++ b/drivers/clk/intel/clk_intel.c
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2019 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <clk-uclass.h>
+#include <dt-bindings/clock/intel-clock.h>
+
+static ulong intel_clk_get_rate(struct clk *clk)
+{
+ ulong rate;
+
+ switch (clk->id) {
+ case CLK_I2C:
+ /* Hard-coded to 133MHz on current platforms */
+ return 133333333;
+ default:
+ return -ENODEV;
+ }
+
+ return rate;
+}
+
+static struct clk_ops intel_clk_ops = {
+ .get_rate = intel_clk_get_rate,
+};
+
+static const struct udevice_id intel_clk_ids[] = {
+ { .compatible = "intel,apl-clk" },
+ { }
+};
+
+U_BOOT_DRIVER(clk_intel) = {
+ .name = "clk_intel",
+ .id = UCLASS_CLK,
+ .of_match = intel_clk_ids,
+ .ops = &intel_clk_ops,
+};