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authorDinh Nguyen <dinguyen@opensource.altera.com>2015-05-19 22:22:42 -0500
committerStephen Boyd <sboyd@codeaurora.org>2015-05-21 15:16:04 -0700
commit5343325ff3dd299f459fa9dacbd95dca5c9bf215 (patch)
treed24df3d0835c546b13ec9bca3ba2b0551aeac33a /drivers/clk/socfpga/clk-periph-a10.c
parent5611a5ba8e5435740df99235b262b553f687b13b (diff)
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>
Diffstat (limited to 'drivers/clk/socfpga/clk-periph-a10.c')
-rw-r--r--drivers/clk/socfpga/clk-periph-a10.c138
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);
+}