diff options
Diffstat (limited to 'drivers/clk/socfpga/clk-periph.c')
| -rw-r--r-- | drivers/clk/socfpga/clk-periph.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/drivers/clk/socfpga/clk-periph.c b/drivers/clk/socfpga/clk-periph.c new file mode 100644 index 000000000..52c883ea7 --- /dev/null +++ b/drivers/clk/socfpga/clk-periph.c @@ -0,0 +1,119 @@ +/* + * Copyright 2011-2012 Calxeda, Inc. + * Copyright (C) 2012-2013 Altera Corporation <www.altera.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that 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. + * + * Based from clk-highbank.c + * + */ +#include <linux/slab.h> +#include <linux/clk-provider.h> +#include <linux/io.h> +#include <linux/of.h> + +#include "clk.h" + +#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, val; + + if (socfpgaclk->fixed_div) { + div = socfpgaclk->fixed_div; + } else { + if (socfpgaclk->div_reg) { + val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift; + val &= GENMASK(socfpgaclk->width - 1, 0); + parent_rate /= (val + 1); + } + div = ((readl(socfpgaclk->hw.reg) & 0x1ff) + 1); + } + + return parent_rate / div; +} + +static u8 clk_periclk_get_parent(struct clk_hw *hwclk) +{ + u32 clk_src; + + clk_src = readl(clk_mgr_base_addr + CLKMGR_DBCTRL); + return clk_src & 0x1; +} + +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[SOCFPGA_MAX_PARENTS]; + struct clk_init_data init; + int rc; + u32 fixed_div; + u32 div_reg[3]; + + of_property_read_u32(node, "reg", ®); + + periph_clk = kzalloc(sizeof(*periph_clk), GFP_KERNEL); + if (WARN_ON(!periph_clk)) + return; + + periph_clk->hw.reg = clk_mgr_base_addr + reg; + + rc = of_property_read_u32_array(node, "div-reg", div_reg, 3); + if (!rc) { + periph_clk->div_reg = clk_mgr_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; + + init.num_parents = of_clk_parent_fill(node, parent_name, + SOCFPGA_MAX_PARENTS); + 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); +} + +void __init socfpga_periph_init(struct device_node *node) +{ + __socfpga_periph_init(node, &periclk_ops); +} |