drivers: clk: Add ZynqMP clock driver

This patch adds CCF compliant clock driver for ZynqMP.
Clock driver queries supported clock information from
firmware and regiters pll and output clocks with CCF.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Tejas Patel <tejasp@xilinx.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Acked-by: Olof Johansson <olof@lixom.net>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

1 files changed, 141 insertions, 0 deletions

diff --git a/drivers/clk/zynqmp/clk-mux-zynqmp.c b/drivers/clk/zynqmp/clk-mux-zynqmp.c
new file mode 100644
index 000000000000..4143f560c28d
--- /dev/null
+++ b/drivers/clk/zynqmp/clk-mux-zynqmp.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Zynq UltraScale+ MPSoC mux
+ *
+ *  Copyright (C) 2016-2018 Xilinx
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/slab.h>
+#include "clk-zynqmp.h"
+
+/*
+ * DOC: basic adjustable multiplexer clock that cannot gate
+ *
+ * Traits of this clock:
+ * prepare - clk_prepare only ensures that parents are prepared
+ * enable - clk_enable only ensures that parents are enabled
+ * rate - rate is only affected by parent switching.  No clk_set_rate support
+ * parent - parent is adjustable through clk_set_parent
+ */
+
+/**
+ * struct zynqmp_clk_mux - multiplexer clock
+ *
+ * @hw:		handle between common and hardware-specific interfaces
+ * @flags:	hardware-specific flags
+ * @clk_id:	Id of clock
+ */
+struct zynqmp_clk_mux {
+	struct clk_hw hw;
+	u8 flags;
+	u32 clk_id;
+};
+
+#define to_zynqmp_clk_mux(_hw) container_of(_hw, struct zynqmp_clk_mux, hw)
+
+/**
+ * zynqmp_clk_mux_get_parent() - Get parent of clock
+ * @hw:		handle between common and hardware-specific interfaces
+ *
+ * Return: Parent index
+ */
+static u8 zynqmp_clk_mux_get_parent(struct clk_hw *hw)
+{
+	struct zynqmp_clk_mux *mux = to_zynqmp_clk_mux(hw);
+	const char *clk_name = clk_hw_get_name(hw);
+	u32 clk_id = mux->clk_id;
+	u32 val;
+	int ret;
+	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
+
+	ret = eemi_ops->clock_getparent(clk_id, &val);
+
+	if (ret)
+		pr_warn_once("%s() getparent failed for clock: %s, ret = %d\n",
+			     __func__, clk_name, ret);
+
+	return val;
+}
+
+/**
+ * zynqmp_clk_mux_set_parent() - Set parent of clock
+ * @hw:		handle between common and hardware-specific interfaces
+ * @index:	Parent index
+ *
+ * Return: 0 on success else error+reason
+ */
+static int zynqmp_clk_mux_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct zynqmp_clk_mux *mux = to_zynqmp_clk_mux(hw);
+	const char *clk_name = clk_hw_get_name(hw);
+	u32 clk_id = mux->clk_id;
+	int ret;
+	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
+
+	ret = eemi_ops->clock_setparent(clk_id, index);
+
+	if (ret)
+		pr_warn_once("%s() set parent failed for clock: %s, ret = %d\n",
+			     __func__, clk_name, ret);
+
+	return ret;
+}
+
+static const struct clk_ops zynqmp_clk_mux_ops = {
+	.get_parent = zynqmp_clk_mux_get_parent,
+	.set_parent = zynqmp_clk_mux_set_parent,
+	.determine_rate = __clk_mux_determine_rate,
+};
+
+static const struct clk_ops zynqmp_clk_mux_ro_ops = {
+	.get_parent = zynqmp_clk_mux_get_parent,
+};
+
+/**
+ * zynqmp_clk_register_mux() - Register a mux table with the clock
+ *			       framework
+ * @name:		Name of this clock
+ * @clk_id:		Id of this clock
+ * @parents:		Name of this clock's parents
+ * @num_parents:	Number of parents
+ * @nodes:		Clock topology node
+ *
+ * Return: clock hardware of the registered clock mux
+ */
+struct clk_hw *zynqmp_clk_register_mux(const char *name, u32 clk_id,
+				       const char * const *parents,
+				       u8 num_parents,
+				       const struct clock_topology *nodes)
+{
+	struct zynqmp_clk_mux *mux;
+	struct clk_hw *hw;
+	struct clk_init_data init;
+	int ret;
+
+	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
+	if (!mux)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	if (nodes->type_flag & CLK_MUX_READ_ONLY)
+		init.ops = &zynqmp_clk_mux_ro_ops;
+	else
+		init.ops = &zynqmp_clk_mux_ops;
+	init.flags = nodes->flag;
+	init.parent_names = parents;
+	init.num_parents = num_parents;
+	mux->flags = nodes->type_flag;
+	mux->hw.init = &init;
+	mux->clk_id = clk_id;
+
+	hw = &mux->hw;
+	ret = clk_hw_register(NULL, hw);
+	if (ret) {
+		kfree(hw);
+		hw = ERR_PTR(ret);
+	}
+
+	return hw;
+}
+EXPORT_SYMBOL_GPL(zynqmp_clk_register_mux);