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clock.c

/*
 *  Copyright (C) 2008 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
 *
 * 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.
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/math64.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>

#include <asm/clkdev.h>

#include <mach/clock.h>
#include <mach/hardware.h>
#include <mach/common.h>
#include "crm_regs.h"

static int _clk_enable(struct clk *clk)
{
      unsigned int reg;

      reg = __raw_readl(clk->enable_reg);
      reg |= 1 << clk->enable_shift;
      __raw_writel(reg, clk->enable_reg);

      return 0;
}

static void _clk_disable(struct clk *clk)
{
      unsigned int reg;

      reg = __raw_readl(clk->enable_reg);
      reg &= ~(1 << clk->enable_shift);
      __raw_writel(reg, clk->enable_reg);
}

static int _clk_can_use_parent(const struct clk *clk_arr[], unsigned int size,
                         struct clk *parent)
{
      int i;

      for (i = 0; i < size; i++)
            if (parent == clk_arr[i])
                  return i;

      return -EINVAL;
}

static unsigned long
_clk_simple_round_rate(struct clk *clk, unsigned long rate, unsigned int limit)
{
      int div;
      unsigned long parent_rate;

      parent_rate = clk_get_rate(clk->parent);

      div = parent_rate / rate;
      if (parent_rate % rate)
            div++;

      if (div > limit)
            div = limit;

      return parent_rate / div;
}

static unsigned long _clk_parent_round_rate(struct clk *clk, unsigned long rate)
{
      return clk->parent->round_rate(clk->parent, rate);
}

static int _clk_parent_set_rate(struct clk *clk, unsigned long rate)
{
      return clk->parent->set_rate(clk->parent, rate);
}

static unsigned long clk16m_get_rate(struct clk *clk)
{
      return 16000000;
}

static struct clk clk16m = {
      .get_rate = clk16m_get_rate,
      .enable = _clk_enable,
      .enable_reg = CCM_CSCR,
      .enable_shift = CCM_CSCR_OSC_EN_SHIFT,
      .disable = _clk_disable,
};

/* in Hz */
static unsigned long clk32_rate;

static unsigned long clk32_get_rate(struct clk *clk)
{
      return clk32_rate;
}

static struct clk clk32 = {
      .get_rate = clk32_get_rate,
};

static unsigned long clk32_premult_get_rate(struct clk *clk)
{
      return clk_get_rate(clk->parent) * 512;
}

static struct clk clk32_premult = {
      .parent = &clk32,
      .get_rate = clk32_premult_get_rate,
};

static const struct clk *prem_clk_clocks[] = {
      &clk32_premult,
      &clk16m,
};

static int prem_clk_set_parent(struct clk *clk, struct clk *parent)
{
      int i;
      unsigned int reg = __raw_readl(CCM_CSCR);

      i = _clk_can_use_parent(prem_clk_clocks, ARRAY_SIZE(prem_clk_clocks),
                        parent);

      switch (i) {
      case 0:
            reg &= ~CCM_CSCR_SYSTEM_SEL;
            break;
      case 1:
            reg |= CCM_CSCR_SYSTEM_SEL;
            break;
      default:
            return i;
      }

      __raw_writel(reg, CCM_CSCR);

      return 0;
}

static struct clk prem_clk = {
      .set_parent = prem_clk_set_parent,
};

static unsigned long system_clk_get_rate(struct clk *clk)
{
      return mxc_decode_pll(__raw_readl(CCM_SPCTL0),
                        clk_get_rate(clk->parent));
}

static struct clk system_clk = {
      .parent = &prem_clk,
      .get_rate = system_clk_get_rate,
};

static unsigned long mcu_clk_get_rate(struct clk *clk)
{
      return mxc_decode_pll(__raw_readl(CCM_MPCTL0),
                        clk_get_rate(clk->parent));
}

static struct clk mcu_clk = {
      .parent = &clk32_premult,
      .get_rate = mcu_clk_get_rate,
};

static unsigned long fclk_get_rate(struct clk *clk)
{
      unsigned long fclk = clk_get_rate(clk->parent);

      if (__raw_readl(CCM_CSCR) & CCM_CSCR_PRESC)
            fclk /= 2;

      return fclk;
}

static struct clk fclk = {
      .parent = &mcu_clk,
      .get_rate = fclk_get_rate,
};

/*
 *  get hclk ( SDRAM, CSI, Memory Stick, I2C, DMA )
 */
static unsigned long hclk_get_rate(struct clk *clk)
{
      return clk_get_rate(clk->parent) / (((__raw_readl(CCM_CSCR) &
                  CCM_CSCR_BCLK_MASK) >> CCM_CSCR_BCLK_OFFSET) + 1);
}

static unsigned long hclk_round_rate(struct clk *clk, unsigned long rate)
{
      return _clk_simple_round_rate(clk, rate, 16);
}

static int hclk_set_rate(struct clk *clk, unsigned long rate)
{
      unsigned int div;
      unsigned int reg;
      unsigned long parent_rate;

      parent_rate = clk_get_rate(clk->parent);

      div = parent_rate / rate;

      if (div > 16 || div < 1 || ((parent_rate / div) != rate))
            return -EINVAL;

      div--;

      reg = __raw_readl(CCM_CSCR);
      reg &= ~CCM_CSCR_BCLK_MASK;
      reg |= div << CCM_CSCR_BCLK_OFFSET;
      __raw_writel(reg, CCM_CSCR);

      return 0;
}

static struct clk hclk = {
      .parent = &system_clk,
      .get_rate = hclk_get_rate,
      .round_rate = hclk_round_rate,
      .set_rate = hclk_set_rate,
};

static unsigned long clk48m_get_rate(struct clk *clk)
{
      return clk_get_rate(clk->parent) / (((__raw_readl(CCM_CSCR) &
                  CCM_CSCR_USB_MASK) >> CCM_CSCR_USB_OFFSET) + 1);
}

static unsigned long clk48m_round_rate(struct clk *clk, unsigned long rate)
{
      return _clk_simple_round_rate(clk, rate, 8);
}

static int clk48m_set_rate(struct clk *clk, unsigned long rate)
{
      unsigned int div;
      unsigned int reg;
      unsigned long parent_rate;

      parent_rate = clk_get_rate(clk->parent);

      div = parent_rate / rate;

      if (div > 8 || div < 1 || ((parent_rate / div) != rate))
            return -EINVAL;

      div--;

      reg = __raw_readl(CCM_CSCR);
      reg &= ~CCM_CSCR_USB_MASK;
      reg |= div << CCM_CSCR_USB_OFFSET;
      __raw_writel(reg, CCM_CSCR);

      return 0;
}

static struct clk clk48m = {
      .parent = &system_clk,
      .get_rate = clk48m_get_rate,
      .round_rate = clk48m_round_rate,
      .set_rate = clk48m_set_rate,
};

/*
 *  get peripheral clock 1 ( UART[12], Timer[12], PWM )
 */
static unsigned long perclk1_get_rate(struct clk *clk)
{
      return clk_get_rate(clk->parent) / (((__raw_readl(CCM_PCDR) &
                  CCM_PCDR_PCLK1_MASK) >> CCM_PCDR_PCLK1_OFFSET) + 1);
}

static unsigned long perclk1_round_rate(struct clk *clk, unsigned long rate)
{
      return _clk_simple_round_rate(clk, rate, 16);
}

static int perclk1_set_rate(struct clk *clk, unsigned long rate)
{
      unsigned int div;
      unsigned int reg;
      unsigned long parent_rate;

      parent_rate = clk_get_rate(clk->parent);

      div = parent_rate / rate;

      if (div > 16 || div < 1 || ((parent_rate / div) != rate))
            return -EINVAL;

      div--;

      reg = __raw_readl(CCM_PCDR);
      reg &= ~CCM_PCDR_PCLK1_MASK;
      reg |= div << CCM_PCDR_PCLK1_OFFSET;
      __raw_writel(reg, CCM_PCDR);

      return 0;
}

/*
 *  get peripheral clock 2 ( LCD, SD, SPI[12] )
 */
static unsigned long perclk2_get_rate(struct clk *clk)
{
      return clk_get_rate(clk->parent) / (((__raw_readl(CCM_PCDR) &
                  CCM_PCDR_PCLK2_MASK) >> CCM_PCDR_PCLK2_OFFSET) + 1);
}

static unsigned long perclk2_round_rate(struct clk *clk, unsigned long rate)
{
      return _clk_simple_round_rate(clk, rate, 16);
}

static int perclk2_set_rate(struct clk *clk, unsigned long rate)
{
      unsigned int div;
      unsigned int reg;
      unsigned long parent_rate;

      parent_rate = clk_get_rate(clk->parent);

      div = parent_rate / rate;

      if (div > 16 || div < 1 || ((parent_rate / div) != rate))
            return -EINVAL;

      div--;

      reg = __raw_readl(CCM_PCDR);
      reg &= ~CCM_PCDR_PCLK2_MASK;
      reg |= div << CCM_PCDR_PCLK2_OFFSET;
      __raw_writel(reg, CCM_PCDR);

      return 0;
}

/*
 *  get peripheral clock 3 ( SSI )
 */
static unsigned long perclk3_get_rate(struct clk *clk)
{
      return clk_get_rate(clk->parent) / (((__raw_readl(CCM_PCDR) &
                  CCM_PCDR_PCLK3_MASK) >> CCM_PCDR_PCLK3_OFFSET) + 1);
}

static unsigned long perclk3_round_rate(struct clk *clk, unsigned long rate)
{
      return _clk_simple_round_rate(clk, rate, 128);
}

static int perclk3_set_rate(struct clk *clk, unsigned long rate)
{
      unsigned int div;
      unsigned int reg;
      unsigned long parent_rate;

      parent_rate = clk_get_rate(clk->parent);

      div = parent_rate / rate;

      if (div > 128 || div < 1 || ((parent_rate / div) != rate))
            return -EINVAL;

      div--;

      reg = __raw_readl(CCM_PCDR);
      reg &= ~CCM_PCDR_PCLK3_MASK;
      reg |= div << CCM_PCDR_PCLK3_OFFSET;
      __raw_writel(reg, CCM_PCDR);

      return 0;
}

static struct clk perclk[] = {
      {
            .id = 0,
            .parent = &system_clk,
            .get_rate = perclk1_get_rate,
            .round_rate = perclk1_round_rate,
            .set_rate = perclk1_set_rate,
      }, {
            .id = 1,
            .parent = &system_clk,
            .get_rate = perclk2_get_rate,
            .round_rate = perclk2_round_rate,
            .set_rate = perclk2_set_rate,
      }, {
            .id = 2,
            .parent = &system_clk,
            .get_rate = perclk3_get_rate,
            .round_rate = perclk3_round_rate,
            .set_rate = perclk3_set_rate,
      }
};

static const struct clk *clko_clocks[] = {
      &perclk[0],
      &hclk,
      &clk48m,
      &clk16m,
      &prem_clk,
      &fclk,
};

static int clko_set_parent(struct clk *clk, struct clk *parent)
{
      int i;
      unsigned int reg;

      i = _clk_can_use_parent(clko_clocks, ARRAY_SIZE(clko_clocks), parent);
      if (i < 0)
            return i;

      reg = __raw_readl(CCM_CSCR) & ~CCM_CSCR_CLKO_MASK;
      reg |= i << CCM_CSCR_CLKO_OFFSET;
      __raw_writel(reg, CCM_CSCR);

      if (clko_clocks[i]->set_rate && clko_clocks[i]->round_rate) {
            clk->set_rate = _clk_parent_set_rate;
            clk->round_rate = _clk_parent_round_rate;
      } else {
            clk->set_rate = NULL;
            clk->round_rate = NULL;
      }

      return 0;
}

static struct clk clko_clk = {
      .set_parent = clko_set_parent,
};

static struct clk dma_clk = {
      .parent = &hclk,
      .round_rate = _clk_parent_round_rate,
      .set_rate = _clk_parent_set_rate,
      .enable = _clk_enable,
      .enable_reg = SCM_GCCR,
      .enable_shift = SCM_GCCR_DMA_CLK_EN_OFFSET,
      .disable = _clk_disable,
};

static struct clk csi_clk = {
      .parent = &hclk,
      .round_rate = _clk_parent_round_rate,
      .set_rate = _clk_parent_set_rate,
      .enable = _clk_enable,
      .enable_reg = SCM_GCCR,
      .enable_shift = SCM_GCCR_CSI_CLK_EN_OFFSET,
      .disable = _clk_disable,
};

static struct clk mma_clk = {
      .parent = &hclk,
      .round_rate = _clk_parent_round_rate,
      .set_rate = _clk_parent_set_rate,
      .enable = _clk_enable,
      .enable_reg = SCM_GCCR,
      .enable_shift = SCM_GCCR_MMA_CLK_EN_OFFSET,
      .disable = _clk_disable,
};

static struct clk usbd_clk = {
      .parent = &clk48m,
      .round_rate = _clk_parent_round_rate,
      .set_rate = _clk_parent_set_rate,
      .enable = _clk_enable,
      .enable_reg = SCM_GCCR,
      .enable_shift = SCM_GCCR_USBD_CLK_EN_OFFSET,
      .disable = _clk_disable,
};

static struct clk gpt_clk = {
      .parent = &perclk[0],
      .round_rate = _clk_parent_round_rate,
      .set_rate = _clk_parent_set_rate,
};

static struct clk uart_clk = {
      .parent = &perclk[0],
      .round_rate = _clk_parent_round_rate,
      .set_rate = _clk_parent_set_rate,
};

static struct clk i2c_clk = {
      .parent = &hclk,
      .round_rate = _clk_parent_round_rate,
      .set_rate = _clk_parent_set_rate,
};

static struct clk spi_clk = {
      .parent = &perclk[1],
      .round_rate = _clk_parent_round_rate,
      .set_rate = _clk_parent_set_rate,
};

static struct clk sdhc_clk = {
      .parent = &perclk[1],
      .round_rate = _clk_parent_round_rate,
      .set_rate = _clk_parent_set_rate,
};

static struct clk lcdc_clk = {
      .parent = &perclk[1],
      .round_rate = _clk_parent_round_rate,
      .set_rate = _clk_parent_set_rate,
};

static struct clk mshc_clk = {
      .parent = &hclk,
      .round_rate = _clk_parent_round_rate,
      .set_rate = _clk_parent_set_rate,
};

static struct clk ssi_clk = {
      .parent = &perclk[2],
      .round_rate = _clk_parent_round_rate,
      .set_rate = _clk_parent_set_rate,
};

static struct clk rtc_clk = {
      .parent = &clk32,
};

#define _REGISTER_CLOCK(d, n, c) \
      { \
            .dev_id = d, \
            .con_id = n, \
            .clk = &c, \
      },
static struct clk_lookup lookups[] __initdata = {
      _REGISTER_CLOCK(NULL, "dma", dma_clk)
      _REGISTER_CLOCK("mx1-camera.0", NULL, csi_clk)
      _REGISTER_CLOCK(NULL, "mma", mma_clk)
      _REGISTER_CLOCK("imx_udc.0", NULL, usbd_clk)
      _REGISTER_CLOCK(NULL, "gpt", gpt_clk)
      _REGISTER_CLOCK("imx-uart.0", NULL, uart_clk)
      _REGISTER_CLOCK("imx-uart.1", NULL, uart_clk)
      _REGISTER_CLOCK("imx-uart.2", NULL, uart_clk)
      _REGISTER_CLOCK("imx-i2c.0", NULL, i2c_clk)
      _REGISTER_CLOCK("spi_imx.0", NULL, spi_clk)
      _REGISTER_CLOCK("imx-mmc.0", NULL, sdhc_clk)
      _REGISTER_CLOCK("imx-fb.0", NULL, lcdc_clk)
      _REGISTER_CLOCK(NULL, "mshc", mshc_clk)
      _REGISTER_CLOCK(NULL, "ssi", ssi_clk)
      _REGISTER_CLOCK("mxc_rtc.0", NULL, rtc_clk)
};

int __init mx1_clocks_init(unsigned long fref)
{
      unsigned int reg;
      int i;

      /* disable clocks we are able to */
      __raw_writel(0, SCM_GCCR);

      clk32_rate = fref;
      reg = __raw_readl(CCM_CSCR);

      /* detect clock reference for system PLL */
      if (reg & CCM_CSCR_SYSTEM_SEL) {
            prem_clk.parent = &clk16m;
      } else {
            /* ensure that oscillator is disabled */
            reg &= ~(1 << CCM_CSCR_OSC_EN_SHIFT);
            __raw_writel(reg, CCM_CSCR);
            prem_clk.parent = &clk32_premult;
      }

      /* detect reference for CLKO */
      reg = (reg & CCM_CSCR_CLKO_MASK) >> CCM_CSCR_CLKO_OFFSET;
      clko_clk.parent = (struct clk *)clko_clocks[reg];

      for (i = 0; i < ARRAY_SIZE(lookups); i++)
            clkdev_add(&lookups[i]);

      clk_enable(&hclk);
      clk_enable(&fclk);

      mxc_timer_init(&gpt_clk, IO_ADDRESS(TIM1_BASE_ADDR), TIM1_INT);

      return 0;
}

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