diff options
Diffstat (limited to 'drivers/clk/socfpga/clk-gate-a10.c')
| -rw-r--r-- | drivers/clk/socfpga/clk-gate-a10.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/drivers/clk/socfpga/clk-gate-a10.c b/drivers/clk/socfpga/clk-gate-a10.c new file mode 100644 index 000000000..637e26bab --- /dev/null +++ b/drivers/clk/socfpga/clk-gate-a10.c @@ -0,0 +1,188 @@ +/* + * 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/mfd/syscon.h> +#include <linux/of.h> +#include <linux/regmap.h> + +#include "clk.h" + +#define streq(a, b) (strcmp((a), (b)) == 0) + +#define to_socfpga_gate_clk(p) container_of(p, struct socfpga_gate_clk, hw.hw) + +/* SDMMC Group for System Manager defines */ +#define SYSMGR_SDMMCGRP_CTRL_OFFSET 0x28 + +static unsigned long socfpga_gate_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 &= GENMASK(socfpgaclk->width - 1, 0); + div = (1 << val); + } + + return parent_rate / div; +} + +static int socfpga_clk_prepare(struct clk_hw *hwclk) +{ + struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk); + int i; + u32 hs_timing; + u32 clk_phase[2]; + + if (socfpgaclk->clk_phase[0] || socfpgaclk->clk_phase[1]) { + for (i = 0; i < ARRAY_SIZE(clk_phase); i++) { + switch (socfpgaclk->clk_phase[i]) { + case 0: + clk_phase[i] = 0; + break; + case 45: + clk_phase[i] = 1; + break; + case 90: + clk_phase[i] = 2; + break; + case 135: + clk_phase[i] = 3; + break; + case 180: + clk_phase[i] = 4; + break; + case 225: + clk_phase[i] = 5; + break; + case 270: + clk_phase[i] = 6; + break; + case 315: + clk_phase[i] = 7; + break; + default: + clk_phase[i] = 0; + break; + } + } + + hs_timing = SYSMGR_SDMMC_CTRL_SET_AS10(clk_phase[0], clk_phase[1]); + if (!IS_ERR(socfpgaclk->sys_mgr_base_addr)) + regmap_write(socfpgaclk->sys_mgr_base_addr, + SYSMGR_SDMMCGRP_CTRL_OFFSET, hs_timing); + else + pr_err("%s: cannot set clk_phase because sys_mgr_base_addr is not available!\n", + __func__); + } + return 0; +} + +static struct clk_ops gateclk_ops = { + .prepare = socfpga_clk_prepare, + .recalc_rate = socfpga_gate_clk_recalc_rate, +}; + +static void __init __socfpga_gate_init(struct device_node *node, + const struct clk_ops *ops) +{ + u32 clk_gate[2]; + u32 div_reg[3]; + u32 clk_phase[2]; + 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; + + 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_a10_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_a10_base_addr + div_reg[0]; + socfpga_clk->shift = div_reg[1]; + socfpga_clk->width = div_reg[2]; + } else { + socfpga_clk->div_reg = NULL; + } + + rc = of_property_read_u32_array(node, "clk-phase", clk_phase, 2); + if (!rc) { + socfpga_clk->clk_phase[0] = clk_phase[0]; + socfpga_clk->clk_phase[1] = clk_phase[1]; + + socfpga_clk->sys_mgr_base_addr = + syscon_regmap_lookup_by_compatible("altr,sys-mgr"); + if (IS_ERR(socfpga_clk->sys_mgr_base_addr)) { + pr_err("%s: failed to find altr,sys-mgr regmap!\n", + __func__); + kfree(socfpga_clk); + return; + } + } + + 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; + 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_a10_gate_init(struct device_node *node) +{ + __socfpga_gate_init(node, &gateclk_ops); +} |