diff options
Diffstat (limited to 'drivers/clk/socfpga')
| -rw-r--r-- | drivers/clk/socfpga/Makefile | 1 | ||||
| -rw-r--r-- | drivers/clk/socfpga/clk.c | 172 |
2 files changed, 173 insertions, 0 deletions
diff --git a/drivers/clk/socfpga/Makefile b/drivers/clk/socfpga/Makefile new file mode 100644 index 00000000..0303c0b9 --- /dev/null +++ b/drivers/clk/socfpga/Makefile @@ -0,0 +1 @@ +obj-y += clk.o diff --git a/drivers/clk/socfpga/clk.c b/drivers/clk/socfpga/clk.c new file mode 100644 index 00000000..bd11315c --- /dev/null +++ b/drivers/clk/socfpga/clk.c @@ -0,0 +1,172 @@ +/* + * 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 + * + * 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.h> +#include <linux/clkdev.h> +#include <linux/clk-provider.h> +#include <linux/io.h> +#include <linux/of.h> + +/* Clock Manager offsets */ +#define CLKMGR_CTRL 0x0 +#define CLKMGR_BYPASS 0x4 + +/* 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 + +extern void __iomem *clk_mgr_base_addr; + +struct socfpga_clk { + struct clk_gate hw; + char *parent_name; + char *clk_name; + u32 fixed_div; +}; +#define to_socfpga_clk(p) container_of(p, struct socfpga_clk, hw.hw) + +static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk, + unsigned long parent_rate) +{ + struct socfpga_clk *socfpgaclk = to_socfpga_clk(hwclk); + unsigned long divf, divq, vco_freq, reg; + 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 = parent_rate * (divf + 1); + return vco_freq / (1 + divq); +} + + +static struct clk_ops clk_pll_ops = { + .recalc_rate = clk_pll_recalc_rate, +}; + +static unsigned long clk_periclk_recalc_rate(struct clk_hw *hwclk, + unsigned long parent_rate) +{ + struct socfpga_clk *socfpgaclk = to_socfpga_clk(hwclk); + u32 div; + + if (socfpgaclk->fixed_div) + div = socfpgaclk->fixed_div; + else + div = ((readl(socfpgaclk->hw.reg) & 0x1ff) + 1); + + return parent_rate / div; +} + +static const struct clk_ops periclk_ops = { + .recalc_rate = clk_periclk_recalc_rate, +}; + +static __init struct clk *socfpga_clk_init(struct device_node *node, + const struct clk_ops *ops) +{ + u32 reg; + struct clk *clk; + struct socfpga_clk *socfpga_clk; + const char *clk_name = node->name; + const char *parent_name; + struct clk_init_data init; + int rc; + u32 fixed_div; + + rc = of_property_read_u32(node, "reg", ®); + if (WARN_ON(rc)) + return NULL; + + socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL); + if (WARN_ON(!socfpga_clk)) + return NULL; + + socfpga_clk->hw.reg = clk_mgr_base_addr + reg; + + rc = of_property_read_u32(node, "fixed-divider", &fixed_div); + if (rc) + socfpga_clk->fixed_div = 0; + else + socfpga_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.parent_names = &parent_name; + init.num_parents = 1; + + socfpga_clk->hw.hw.init = &init; + + if (strcmp(clk_name, "main_pll") || strcmp(clk_name, "periph_pll") || + strcmp(clk_name, "sdram_pll")) { + socfpga_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, &socfpga_clk->hw.hw); + if (WARN_ON(IS_ERR(clk))) { + kfree(socfpga_clk); + return NULL; + } + rc = of_clk_add_provider(node, of_clk_src_simple_get, clk); + return clk; +} + +static void __init socfpga_pll_init(struct device_node *node) +{ + socfpga_clk_init(node, &clk_pll_ops); +} +CLK_OF_DECLARE(socfpga_pll, "altr,socfpga-pll-clock", socfpga_pll_init); + +static void __init socfpga_periph_init(struct device_node *node) +{ + socfpga_clk_init(node, &periclk_ops); +} +CLK_OF_DECLARE(socfpga_periph, "altr,socfpga-perip-clk", socfpga_periph_init); + +void __init socfpga_init_clocks(void) +{ + struct clk *clk; + int ret; + + clk = clk_register_fixed_factor(NULL, "smp_twd", "mpuclk", 0, 1, 4); + ret = clk_register_clkdev(clk, NULL, "smp_twd"); + if (ret) + pr_err("smp_twd alias not registered\n"); +} |