clk: socfpga: add a clock driver for the Arria 10 platform

The clocks on the Arria 10 platform is a bit different than the
Cyclone/Arria 5 platform that it should just have it's own
driver.

Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

1 files changed, 138 insertions, 0 deletions

diff --git a/drivers/clk/socfpga/clk-periph-a10.c b/drivers/clk/socfpga/clk-periph-a10.c
new file mode 100644
index 000000000000..9d0181b5a6a4
--- /dev/null
+++ b/drivers/clk/socfpga/clk-periph-a10.c
@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2015 Altera Corporation. All rights reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+#include <linux/of.h>
+
+#include "clk.h"
+
+#define CLK_MGR_FREE_SHIFT		16
+#define CLK_MGR_FREE_MASK		0x7
+
+#define SOCFPGA_MPU_FREE_CLK		"mpu_free_clk"
+#define SOCFPGA_NOC_FREE_CLK		"noc_free_clk"
+#define SOCFPGA_SDMMC_FREE_CLK		"sdmmc_free_clk"
+#define to_socfpga_periph_clk(p) container_of(p, struct socfpga_periph_clk, hw.hw)
+
+static unsigned long clk_periclk_recalc_rate(struct clk_hw *hwclk,
+					     unsigned long parent_rate)
+{
+	struct socfpga_periph_clk *socfpgaclk = to_socfpga_periph_clk(hwclk);
+	u32 div;
+
+	if (socfpgaclk->fixed_div) {
+		div = socfpgaclk->fixed_div;
+	} else if (socfpgaclk->div_reg) {
+		div = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
+		div &= div_mask(socfpgaclk->width);
+		div += 1;
+	} else {
+		div = ((readl(socfpgaclk->hw.reg) & 0x7ff) + 1);
+	}
+
+	return parent_rate / div;
+}
+
+static u8 clk_periclk_get_parent(struct clk_hw *hwclk)
+{
+	struct socfpga_periph_clk *socfpgaclk = to_socfpga_periph_clk(hwclk);
+	u32 clk_src;
+
+	clk_src = readl(socfpgaclk->hw.reg);
+	if (streq(hwclk->init->name, SOCFPGA_MPU_FREE_CLK) ||
+	    streq(hwclk->init->name, SOCFPGA_NOC_FREE_CLK) ||
+	    streq(hwclk->init->name, SOCFPGA_SDMMC_FREE_CLK))
+		return (clk_src >> CLK_MGR_FREE_SHIFT) &
+			CLK_MGR_FREE_MASK;
+	else
+		return 0;
+}
+
+static const struct clk_ops periclk_ops = {
+	.recalc_rate = clk_periclk_recalc_rate,
+	.get_parent = clk_periclk_get_parent,
+};
+
+static __init void __socfpga_periph_init(struct device_node *node,
+	const struct clk_ops *ops)
+{
+	u32 reg;
+	struct clk *clk;
+	struct socfpga_periph_clk *periph_clk;
+	const char *clk_name = node->name;
+	const char *parent_name;
+	struct clk_init_data init;
+	int rc;
+	u32 fixed_div;
+	u32 div_reg[3];
+
+	of_property_read_u32(node, "reg", &reg);
+
+	periph_clk = kzalloc(sizeof(*periph_clk), GFP_KERNEL);
+	if (WARN_ON(!periph_clk))
+		return;
+
+	periph_clk->hw.reg = clk_mgr_a10_base_addr + reg;
+
+	rc = of_property_read_u32_array(node, "div-reg", div_reg, 3);
+	if (!rc) {
+		periph_clk->div_reg = clk_mgr_a10_base_addr + div_reg[0];
+		periph_clk->shift = div_reg[1];
+		periph_clk->width = div_reg[2];
+	} else {
+		periph_clk->div_reg = NULL;
+	}
+
+	rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
+	if (rc)
+		periph_clk->fixed_div = 0;
+	else
+		periph_clk->fixed_div = fixed_div;
+
+	of_property_read_string(node, "clock-output-names", &clk_name);
+
+	init.name = clk_name;
+	init.ops = ops;
+	init.flags = 0;
+
+	parent_name = of_clk_get_parent_name(node, 0);
+	init.num_parents = 1;
+	init.parent_names = &parent_name;
+
+	periph_clk->hw.hw.init = &init;
+
+	clk = clk_register(NULL, &periph_clk->hw.hw);
+	if (WARN_ON(IS_ERR(clk))) {
+		kfree(periph_clk);
+		return;
+	}
+	rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
+	if (rc < 0) {
+		pr_err("Could not register clock provider for node:%s\n",
+		       clk_name);
+		goto err_clk;
+	}
+
+	return;
+
+err_clk:
+	clk_unregister(clk);
+}
+
+void __init socfpga_a10_periph_init(struct device_node *node)
+{
+	__socfpga_periph_init(node, &periclk_ops);
+}