ispcsiphy.c

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/*
 * ispcsiphy.c
 *
 * TI OMAP3 ISP - CSI PHY module
 *
 * Copyright (C) 2010 Nokia Corporation
 * Copyright (C) 2009 Texas Instruments, Inc.
 *
 * Contacts: Laurent Pinchart <[email protected]>
 *       Sakari Ailus <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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/delay.h>
#include <linux/device.h>
#include <linux/regulator/consumer.h>

#include "isp.h"
#include "ispreg.h"
#include "ispcsiphy.h"

/*
 * csiphy_lanes_config - Configuration of CSIPHY lanes.
 *
 * Updates HW configuration.
 * Called with phy->mutex taken.
 */
static void csiphy_lanes_config(struct isp_csiphy *phy)
{
    unsigned int i;
    u32 reg;

    reg = isp_reg_readl(phy->isp, phy->cfg_regs, ISPCSI2_PHY_CFG);

    for (i = 0; i < phy->num_data_lanes; i++) {
        reg &= ~(ISPCSI2_PHY_CFG_DATA_POL_MASK(i + 1) |
             ISPCSI2_PHY_CFG_DATA_POSITION_MASK(i + 1));
        reg |= (phy->lanes.data[i].pol <<
            ISPCSI2_PHY_CFG_DATA_POL_SHIFT(i + 1));
        reg |= (phy->lanes.data[i].pos <<
            ISPCSI2_PHY_CFG_DATA_POSITION_SHIFT(i + 1));
    }

    reg &= ~(ISPCSI2_PHY_CFG_CLOCK_POL_MASK |
         ISPCSI2_PHY_CFG_CLOCK_POSITION_MASK);
    reg |= phy->lanes.clk.pol << ISPCSI2_PHY_CFG_CLOCK_POL_SHIFT;
    reg |= phy->lanes.clk.pos << ISPCSI2_PHY_CFG_CLOCK_POSITION_SHIFT;

    isp_reg_writel(phy->isp, reg, phy->cfg_regs, ISPCSI2_PHY_CFG);
}

/*
 * csiphy_power_autoswitch_enable
 * @enable: Sets or clears the autoswitch function enable flag.
 */
static void csiphy_power_autoswitch_enable(struct isp_csiphy *phy, bool enable)
{
    isp_reg_clr_set(phy->isp, phy->cfg_regs, ISPCSI2_PHY_CFG,
            ISPCSI2_PHY_CFG_PWR_AUTO,
            enable ? ISPCSI2_PHY_CFG_PWR_AUTO : 0);
}

/*
 * csiphy_set_power
 * @power: Power state to be set.
 *
 * Returns 0 if successful, or -EBUSY if the retry count is exceeded.
 */
static int csiphy_set_power(struct isp_csiphy *phy, u32 power)
{
    u32 reg;
    u8 retry_count;

    isp_reg_clr_set(phy->isp, phy->cfg_regs, ISPCSI2_PHY_CFG,
            ISPCSI2_PHY_CFG_PWR_CMD_MASK, power);

    retry_count = 0;
    do {
        udelay(50);
        reg = isp_reg_readl(phy->isp, phy->cfg_regs, ISPCSI2_PHY_CFG) &
                    ISPCSI2_PHY_CFG_PWR_STATUS_MASK;

        if (reg != power >> 2)
            retry_count++;

    } while ((reg != power >> 2) && (retry_count < 100));

    if (retry_count == 100) {
        printk(KERN_ERR "CSI2 CIO set power failed!\n");
        return -EBUSY;
    }

    return 0;
}

/*
 * csiphy_dphy_config - Configure CSI2 D-PHY parameters.
 *
 * Called with phy->mutex taken.
 */
static void csiphy_dphy_config(struct isp_csiphy *phy)
{
    u32 reg;

    /* Set up ISPCSIPHY_REG0 */
    reg = isp_reg_readl(phy->isp, phy->phy_regs, ISPCSIPHY_REG0);

    reg &= ~(ISPCSIPHY_REG0_THS_TERM_MASK |
         ISPCSIPHY_REG0_THS_SETTLE_MASK);
    reg |= phy->dphy.ths_term << ISPCSIPHY_REG0_THS_TERM_SHIFT;
    reg |= phy->dphy.ths_settle << ISPCSIPHY_REG0_THS_SETTLE_SHIFT;

    isp_reg_writel(phy->isp, reg, phy->phy_regs, ISPCSIPHY_REG0);

    /* Set up ISPCSIPHY_REG1 */
    reg = isp_reg_readl(phy->isp, phy->phy_regs, ISPCSIPHY_REG1);

    reg &= ~(ISPCSIPHY_REG1_TCLK_TERM_MASK |
         ISPCSIPHY_REG1_TCLK_MISS_MASK |
         ISPCSIPHY_REG1_TCLK_SETTLE_MASK);
    reg |= phy->dphy.tclk_term << ISPCSIPHY_REG1_TCLK_TERM_SHIFT;
    reg |= phy->dphy.tclk_miss << ISPCSIPHY_REG1_TCLK_MISS_SHIFT;
    reg |= phy->dphy.tclk_settle << ISPCSIPHY_REG1_TCLK_SETTLE_SHIFT;

    isp_reg_writel(phy->isp, reg, phy->phy_regs, ISPCSIPHY_REG1);
}

static int csiphy_config(struct isp_csiphy *phy,
             struct isp_csiphy_dphy_cfg *dphy,
             struct isp_csiphy_lanes_cfg *lanes)
{
    unsigned int used_lanes = 0;
    unsigned int i;

    /* Clock and data lanes verification */
    for (i = 0; i < phy->num_data_lanes; i++) {
        if (lanes->data[i].pol > 1 || lanes->data[i].pos > 3)
            return -EINVAL;

        if (used_lanes & (1 << lanes->data[i].pos))
            return -EINVAL;

        used_lanes |= 1 << lanes->data[i].pos;
    }

    if (lanes->clk.pol > 1 || lanes->clk.pos > 3)
        return -EINVAL;

    if (lanes->clk.pos == 0 || used_lanes & (1 << lanes->clk.pos))
        return -EINVAL;

    mutex_lock(&phy->mutex);
    phy->dphy = *dphy;
    phy->lanes = *lanes;
    mutex_unlock(&phy->mutex);

    return 0;
}

int omap3isp_csiphy_acquire(struct isp_csiphy *phy)
{
    int rval;

    if (phy->vdd == NULL) {
        dev_err(phy->isp->dev, "Power regulator for CSI PHY not "
            "available\n");
        return -ENODEV;
    }

    mutex_lock(&phy->mutex);

    rval = regulator_enable(phy->vdd);
    if (rval < 0)
        goto done;

    rval = omap3isp_csi2_reset(phy->csi2);
    if (rval < 0)
        goto done;

    csiphy_dphy_config(phy);
    csiphy_lanes_config(phy);

    rval = csiphy_set_power(phy, ISPCSI2_PHY_CFG_PWR_CMD_ON);
    if (rval) {
        regulator_disable(phy->vdd);
        goto done;
    }

    csiphy_power_autoswitch_enable(phy, true);
    phy->phy_in_use = 1;

done:
    mutex_unlock(&phy->mutex);
    return rval;
}

void omap3isp_csiphy_release(struct isp_csiphy *phy)
{
    mutex_lock(&phy->mutex);
    if (phy->phy_in_use) {
        csiphy_power_autoswitch_enable(phy, false);
        csiphy_set_power(phy, ISPCSI2_PHY_CFG_PWR_CMD_OFF);
        regulator_disable(phy->vdd);
        phy->phy_in_use = 0;
    }
    mutex_unlock(&phy->mutex);
}

/*
 * omap3isp_csiphy_init - Initialize the CSI PHY frontends
 */
int omap3isp_csiphy_init(struct isp_device *isp)
{
    struct isp_csiphy *phy1 = &isp->isp_csiphy1;
    struct isp_csiphy *phy2 = &isp->isp_csiphy2;

    isp->platform_cb.csiphy_config = csiphy_config;

    phy2->isp = isp;
    phy2->csi2 = &isp->isp_csi2a;
    phy2->num_data_lanes = ISP_CSIPHY2_NUM_DATA_LANES;
    phy2->cfg_regs = OMAP3_ISP_IOMEM_CSI2A_REGS1;
    phy2->phy_regs = OMAP3_ISP_IOMEM_CSIPHY2;
    mutex_init(&phy2->mutex);

    if (isp->revision == ISP_REVISION_15_0) {
        phy1->isp = isp;
        phy1->csi2 = &isp->isp_csi2c;
        phy1->num_data_lanes = ISP_CSIPHY1_NUM_DATA_LANES;
        phy1->cfg_regs = OMAP3_ISP_IOMEM_CSI2C_REGS1;
        phy1->phy_regs = OMAP3_ISP_IOMEM_CSIPHY1;
        mutex_init(&phy1->mutex);
    }

    return 0;
}