diff options
Diffstat (limited to 'drivers/clk/socfpga/clk-gate.c')
| -rw-r--r-- | drivers/clk/socfpga/clk-gate.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/drivers/clk/socfpga/clk-gate.c b/drivers/clk/socfpga/clk-gate.c new file mode 100644 index 000000000000..4efcf4e33a82 --- /dev/null +++ b/drivers/clk/socfpga/clk-gate.c @@ -0,0 +1,195 @@ +/* + * 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/clk.h> +#include <linux/clkdev.h> +#include <linux/clk-provider.h> +#include <linux/io.h> +#include <linux/of.h> + +#include "clk.h" + +#define SOCFPGA_L4_MP_CLK "l4_mp_clk" +#define SOCFPGA_L4_SP_CLK "l4_sp_clk" +#define SOCFPGA_NAND_CLK "nand_clk" +#define SOCFPGA_NAND_X_CLK "nand_x_clk" +#define SOCFPGA_MMC_CLK "sdmmc_clk" +#define SOCFPGA_GPIO_DB_CLK_OFFSET 0xA8 + +#define div_mask(width) ((1 << (width)) - 1) +#define streq(a, b) (strcmp((a), (b)) == 0) + +#define to_socfpga_gate_clk(p) container_of(p, struct socfpga_gate_clk, hw.hw) + +static u8 socfpga_clk_get_parent(struct clk_hw *hwclk) +{ + u32 l4_src; + u32 perpll_src; + + if (streq(hwclk->init->name, SOCFPGA_L4_MP_CLK)) { + l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC); + return l4_src &= 0x1; + } + if (streq(hwclk->init->name, SOCFPGA_L4_SP_CLK)) { + l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC); + return !!(l4_src & 2); + } + + perpll_src = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC); + if (streq(hwclk->init->name, SOCFPGA_MMC_CLK)) + return perpll_src &= 0x3; + if (streq(hwclk->init->name, SOCFPGA_NAND_CLK) || + streq(hwclk->init->name, SOCFPGA_NAND_X_CLK)) + return (perpll_src >> 2) & 3; + + /* QSPI clock */ + return (perpll_src >> 4) & 3; + +} + +static int socfpga_clk_set_parent(struct clk_hw *hwclk, u8 parent) +{ + u32 src_reg; + + if (streq(hwclk->init->name, SOCFPGA_L4_MP_CLK)) { + src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC); + src_reg &= ~0x1; + src_reg |= parent; + writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC); + } else if (streq(hwclk->init->name, SOCFPGA_L4_SP_CLK)) { + src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC); + src_reg &= ~0x2; + src_reg |= (parent << 1); + writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC); + } else { + src_reg = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC); + if (streq(hwclk->init->name, SOCFPGA_MMC_CLK)) { + src_reg &= ~0x3; + src_reg |= parent; + } else if (streq(hwclk->init->name, SOCFPGA_NAND_CLK) || + streq(hwclk->init->name, SOCFPGA_NAND_X_CLK)) { + src_reg &= ~0xC; + src_reg |= (parent << 2); + } else {/* QSPI clock */ + src_reg &= ~0x30; + src_reg |= (parent << 4); + } + writel(src_reg, clk_mgr_base_addr + CLKMGR_PERPLL_SRC); + } + + return 0; +} + +static unsigned long socfpga_clk_recalc_rate(struct clk_hw *hwclk, + unsigned long parent_rate) +{ + struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk); + u32 div = 1, val; + + if (socfpgaclk->fixed_div) + div = socfpgaclk->fixed_div; + else if (socfpgaclk->div_reg) { + val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift; + val &= div_mask(socfpgaclk->width); + /* Check for GPIO_DB_CLK by its offset */ + if ((int) socfpgaclk->div_reg & SOCFPGA_GPIO_DB_CLK_OFFSET) + div = val + 1; + else + div = (1 << val); + } + + return parent_rate / div; +} + +static struct clk_ops gateclk_ops = { + .recalc_rate = socfpga_clk_recalc_rate, + .get_parent = socfpga_clk_get_parent, + .set_parent = socfpga_clk_set_parent, +}; + +static void __init __socfpga_gate_init(struct device_node *node, + const struct clk_ops *ops) +{ + u32 clk_gate[2]; + u32 div_reg[3]; + u32 fixed_div; + struct clk *clk; + struct socfpga_gate_clk *socfpga_clk; + const char *clk_name = node->name; + const char *parent_name[SOCFPGA_MAX_PARENTS]; + struct clk_init_data init; + int rc; + int i = 0; + + socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL); + if (WARN_ON(!socfpga_clk)) + return; + + rc = of_property_read_u32_array(node, "clk-gate", clk_gate, 2); + if (rc) + clk_gate[0] = 0; + + if (clk_gate[0]) { + socfpga_clk->hw.reg = clk_mgr_base_addr + clk_gate[0]; + socfpga_clk->hw.bit_idx = clk_gate[1]; + + gateclk_ops.enable = clk_gate_ops.enable; + gateclk_ops.disable = clk_gate_ops.disable; + } + + rc = of_property_read_u32(node, "fixed-divider", &fixed_div); + if (rc) + socfpga_clk->fixed_div = 0; + else + socfpga_clk->fixed_div = fixed_div; + + rc = of_property_read_u32_array(node, "div-reg", div_reg, 3); + if (!rc) { + socfpga_clk->div_reg = clk_mgr_base_addr + div_reg[0]; + socfpga_clk->shift = div_reg[1]; + socfpga_clk->width = div_reg[2]; + } else { + socfpga_clk->div_reg = 0; + } + + of_property_read_string(node, "clock-output-names", &clk_name); + + init.name = clk_name; + init.ops = ops; + init.flags = 0; + while (i < SOCFPGA_MAX_PARENTS && (parent_name[i] = + of_clk_get_parent_name(node, i)) != NULL) + i++; + + init.parent_names = parent_name; + init.num_parents = i; + socfpga_clk->hw.hw.init = &init; + + clk = clk_register(NULL, &socfpga_clk->hw.hw); + if (WARN_ON(IS_ERR(clk))) { + kfree(socfpga_clk); + return; + } + rc = of_clk_add_provider(node, of_clk_src_simple_get, clk); + if (WARN_ON(rc)) + return; +} + +void __init socfpga_gate_init(struct device_node *node) +{ + __socfpga_gate_init(node, &gateclk_ops); +} |