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kernel/linux-imx6_3.14.28/drivers/clk/shmobile/clk-emev2.c 3.14 KB
6b13f685e   김민수   BSP 최초 추가
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  /*
   * EMMA Mobile EV2 common clock framework support
   *
   * Copyright (C) 2013 Takashi Yoshii <takashi.yoshii.ze@renesas.com>
   * Copyright (C) 2012 Magnus Damm
   *
   * 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; version 2 of the License.
   *
   * 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.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   */
  #include <linux/clk-provider.h>
  #include <linux/clkdev.h>
  #include <linux/io.h>
  #include <linux/of.h>
  #include <linux/of_address.h>
  
  /* EMEV2 SMU registers */
  #define USIAU0_RSTCTRL 0x094
  #define USIBU1_RSTCTRL 0x0ac
  #define USIBU2_RSTCTRL 0x0b0
  #define USIBU3_RSTCTRL 0x0b4
  #define STI_RSTCTRL 0x124
  #define STI_CLKSEL 0x688
  
  static DEFINE_SPINLOCK(lock);
  
  /* not pretty, but hey */
  void __iomem *smu_base;
  
  static void __init emev2_smu_write(unsigned long value, int offs)
  {
  	BUG_ON(!smu_base || (offs >= PAGE_SIZE));
  	writel_relaxed(value, smu_base + offs);
  }
  
  static const struct of_device_id smu_id[] __initconst = {
  	{ .compatible = "renesas,emev2-smu", },
  	{},
  };
  
  static void __init emev2_smu_init(void)
  {
  	struct device_node *np;
  
  	np = of_find_matching_node(NULL, smu_id);
  	BUG_ON(!np);
  	smu_base = of_iomap(np, 0);
  	BUG_ON(!smu_base);
  	of_node_put(np);
  
  	/* setup STI timer to run on 32.768 kHz and deassert reset */
  	emev2_smu_write(0, STI_CLKSEL);
  	emev2_smu_write(1, STI_RSTCTRL);
  
  	/* deassert reset for UART0->UART3 */
  	emev2_smu_write(2, USIAU0_RSTCTRL);
  	emev2_smu_write(2, USIBU1_RSTCTRL);
  	emev2_smu_write(2, USIBU2_RSTCTRL);
  	emev2_smu_write(2, USIBU3_RSTCTRL);
  }
  
  static void __init emev2_smu_clkdiv_init(struct device_node *np)
  {
  	u32 reg[2];
  	struct clk *clk;
  	const char *parent_name = of_clk_get_parent_name(np, 0);
  	if (WARN_ON(of_property_read_u32_array(np, "reg", reg, 2)))
  		return;
  	if (!smu_base)
  		emev2_smu_init();
  	clk = clk_register_divider(NULL, np->name, parent_name, 0,
  				   smu_base + reg[0], reg[1], 8, 0, &lock);
  	of_clk_add_provider(np, of_clk_src_simple_get, clk);
  	clk_register_clkdev(clk, np->name, NULL);
  	pr_debug("## %s %s %p
  ", __func__, np->name, clk);
  }
  CLK_OF_DECLARE(emev2_smu_clkdiv, "renesas,emev2-smu-clkdiv",
  		emev2_smu_clkdiv_init);
  
  static void __init emev2_smu_gclk_init(struct device_node *np)
  {
  	u32 reg[2];
  	struct clk *clk;
  	const char *parent_name = of_clk_get_parent_name(np, 0);
  	if (WARN_ON(of_property_read_u32_array(np, "reg", reg, 2)))
  		return;
  	if (!smu_base)
  		emev2_smu_init();
  	clk = clk_register_gate(NULL, np->name, parent_name, 0,
  				smu_base + reg[0], reg[1], 0, &lock);
  	of_clk_add_provider(np, of_clk_src_simple_get, clk);
  	clk_register_clkdev(clk, np->name, NULL);
  	pr_debug("## %s %s %p
  ", __func__, np->name, clk);
  }
  CLK_OF_DECLARE(emev2_smu_gclk, "renesas,emev2-smu-gclk", emev2_smu_gclk_init);