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kernel/linux-rt-4.4.41/drivers/clk/socfpga/clk-gate-a10.c 4.75 KB
5113f6f70   김현기   kernel add
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  /*
   * 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(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!
  ",
  					__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;
  	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_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!
  ",
  					__func__);
  			return;
  		}
  	}
  
  	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_a10_gate_init(struct device_node *node)
  {
  	__socfpga_gate_init(node, &gateclk_ops);
  }