diff options
Diffstat (limited to 'drivers/clk/socfpga/clk-periph-a10.c')
| -rw-r--r-- | drivers/clk/socfpga/clk-periph-a10.c | 138 |
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 000000000..70993f1e8 --- /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/slab.h> +#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 &= GENMASK(socfpgaclk->width - 1, 0); + 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[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_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; + + 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); + 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); +} |