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Diffstat (limited to '')
| -rw-r--r-- | drivers/clk/socfpga/clk-pll.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/drivers/clk/socfpga/clk-pll.c b/drivers/clk/socfpga/clk-pll.c new file mode 100644 index 000000000..b4b44e9b5 --- /dev/null +++ b/drivers/clk/socfpga/clk-pll.c @@ -0,0 +1,133 @@ +/* + * 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 <linux/of_address.h> + +#include "clk.h" + +/* Clock bypass bits */ +#define MAINPLL_BYPASS (1<<0) +#define SDRAMPLL_BYPASS (1<<1) +#define SDRAMPLL_SRC_BYPASS (1<<2) +#define PERPLL_BYPASS (1<<3) +#define PERPLL_SRC_BYPASS (1<<4) + +#define SOCFPGA_PLL_BG_PWRDWN 0 +#define SOCFPGA_PLL_EXT_ENA 1 +#define SOCFPGA_PLL_PWR_DOWN 2 +#define SOCFPGA_PLL_DIVF_MASK 0x0000FFF8 +#define SOCFPGA_PLL_DIVF_SHIFT 3 +#define SOCFPGA_PLL_DIVQ_MASK 0x003F0000 +#define SOCFPGA_PLL_DIVQ_SHIFT 16 + +#define CLK_MGR_PLL_CLK_SRC_SHIFT 22 +#define CLK_MGR_PLL_CLK_SRC_MASK 0x3 + +#define to_socfpga_clk(p) container_of(p, struct socfpga_pll, hw.hw) + +void __iomem *clk_mgr_base_addr; + +static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk, + unsigned long parent_rate) +{ + struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk); + unsigned long divf, divq, reg; + unsigned long long vco_freq; + unsigned long bypass; + + reg = readl(socfpgaclk->hw.reg); + bypass = readl(clk_mgr_base_addr + CLKMGR_BYPASS); + if (bypass & MAINPLL_BYPASS) + return parent_rate; + + divf = (reg & SOCFPGA_PLL_DIVF_MASK) >> SOCFPGA_PLL_DIVF_SHIFT; + divq = (reg & SOCFPGA_PLL_DIVQ_MASK) >> SOCFPGA_PLL_DIVQ_SHIFT; + vco_freq = (unsigned long long)parent_rate * (divf + 1); + do_div(vco_freq, (1 + divq)); + return (unsigned long)vco_freq; +} + +static u8 clk_pll_get_parent(struct clk_hw *hwclk) +{ + u32 pll_src; + struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk); + + pll_src = readl(socfpgaclk->hw.reg); + return (pll_src >> CLK_MGR_PLL_CLK_SRC_SHIFT) & + CLK_MGR_PLL_CLK_SRC_MASK; +} + +static struct clk_ops clk_pll_ops = { + .recalc_rate = clk_pll_recalc_rate, + .get_parent = clk_pll_get_parent, +}; + +static __init struct clk *__socfpga_pll_init(struct device_node *node, + const struct clk_ops *ops) +{ + u32 reg; + struct clk *clk; + struct socfpga_pll *pll_clk; + const char *clk_name = node->name; + const char *parent_name[SOCFPGA_MAX_PARENTS]; + struct clk_init_data init; + struct device_node *clkmgr_np; + int rc; + + of_property_read_u32(node, "reg", ®); + + pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL); + if (WARN_ON(!pll_clk)) + return NULL; + + clkmgr_np = of_find_compatible_node(NULL, NULL, "altr,clk-mgr"); + clk_mgr_base_addr = of_iomap(clkmgr_np, 0); + of_node_put(clkmgr_np); + BUG_ON(!clk_mgr_base_addr); + pll_clk->hw.reg = clk_mgr_base_addr + reg; + + 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; + pll_clk->hw.hw.init = &init; + + pll_clk->hw.bit_idx = SOCFPGA_PLL_EXT_ENA; + clk_pll_ops.enable = clk_gate_ops.enable; + clk_pll_ops.disable = clk_gate_ops.disable; + + clk = clk_register(NULL, &pll_clk->hw.hw); + if (WARN_ON(IS_ERR(clk))) { + kfree(pll_clk); + return NULL; + } + rc = of_clk_add_provider(node, of_clk_src_simple_get, clk); + return clk; +} + +void __init socfpga_pll_init(struct device_node *node) +{ + __socfpga_pll_init(node, &clk_pll_ops); +} |