linux-imx

/*

 * DaVinci DA850 AHCI SATA platform driver

 *

 * 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, or (at your option)

 * any later version.

 */

​

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/pm.h>

#include <linux/device.h>

#include <linux/platform_device.h>

#include <linux/libata.h>

#include <linux/ahci_platform.h>

#include "ahci.h"

​

#define DRV_NAME        "ahci_da850"

#define HARDRESET_RETRIES   5

​

/* SATA PHY Control Register offset from AHCI base */

#define SATA_P0PHYCR_REG    0x178

​

#define SATA_PHY_MPY(x)     ((x) << 0)

#define SATA_PHY_LOS(x)     ((x) << 6)

#define SATA_PHY_RXCDR(x)   ((x) << 10)

#define SATA_PHY_RXEQ(x)    ((x) << 13)

#define SATA_PHY_TXSWING(x) ((x) << 19)

#define SATA_PHY_ENPLL(x)   ((x) << 31)

​

static void da850_sata_init(struct device *dev, void __iomem *pwrdn_reg,

                void __iomem *ahci_base, u32 mpy)

{

    unsigned int val;

​

    /* Enable SATA clock receiver */

    val = readl(pwrdn_reg);

    val &= ~BIT(0);

    writel(val, pwrdn_reg);

​

    val = SATA_PHY_MPY(mpy) | SATA_PHY_LOS(1) | SATA_PHY_RXCDR(4) |

          SATA_PHY_RXEQ(1) | SATA_PHY_TXSWING(3) | SATA_PHY_ENPLL(1);

​

    writel(val, ahci_base + SATA_P0PHYCR_REG);

}

​

static u32 ahci_da850_calculate_mpy(unsigned long refclk_rate)

{

    u32 pll_output = 1500000000, needed;

​

    /*

     * We need to determine the value of the multiplier (MPY) bits.

     * In order to include the 12.5 multiplier we need to first divide

     * the refclk rate by ten.

     *

     * __div64_32() turned out to be unreliable, sometimes returning

     * false results.

     */

    WARN((refclk_rate % 10) != 0, "refclk must be divisible by 10");

    needed = pll_output / (refclk_rate / 10);

​

    /*

     * What we have now is (multiplier * 10).

     *

     * Let's determine the actual register value we need to write.

     */

​

    switch (needed) {

    case 50:

        return 0x1;

    case 60:

        return 0x2;

    case 80:

        return 0x4;

    case 100:

        return 0x5;

    case 120:

        return 0x6;

    case 125:

        return 0x7;

    case 150:

        return 0x8;

    case 200:

        return 0x9;

    case 250:

        return 0xa;

    default:

        /*

         * We should have divided evenly - if not, return an invalid

         * value.

         */