rockbox/firmware/target/arm/imx31/gigabeat-s/fmradio-i2c-gigabeat-s.c

/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 * Physical interface of the SI4700 in the Gigabeat S
 *
 * Copyright (C) 2008 by Nils Wallménius
 *
 * 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/

#include "config.h"
#include "system.h"
#include "kernel.h"
#include "thread.h"
#include "mc13783.h"
#include "iomuxc-imx31.h"
#include "gpio-target.h"
#include "i2c-imx31.h"
#include "fmradio_i2c.h"
#include "tuner.h"

static struct i2c_node si4700_i2c_node =
{
    .num  = I2C2_NUM,
    .ifdr = I2C_IFDR_DIV192, /* 66MHz/.4MHz = 165, closest = 192 = 343750Hz */
    .addr = (0x20),
};

void fmradio_i2c_init(void)
{
    /* RST: LOW */
    bitclr32(&GPIO1_DR, (1 << 26));
    /* RST: OUT */
    bitset32(&GPIO1_GDIR, (1 << 26));

    /* I2C2 SCL: IN, I2C2: SDA IN */
    bitclr32(&GPIO2_GDIR, (3 << 14));
    /* I2C2 SCL LO, I2C2 SDA LO */
    bitclr32(&GPIO2_DR, (3 << 14));

    /* open-drain pins - external pullups on PCB. Pullup default but
     * disabled */
    /* RI_DTE1 (I2C2_SCLK) */                          
    iomuxc_set_pad_config(IOMUXC_RI_DTE1,
        IOMUXC_PAD_PUE_PKE_DISABLE | IOMUXC_PAD_PUS_UP_100K |
        IOMUXC_PAD_HYS | IOMUXC_PAD_ODE);
    /* DCD_DTE1 (I2C2_SDA) */
    iomuxc_set_pad_config(IOMUXC_DCD_DTE1,
        IOMUXC_PAD_PUE_PKE_DISABLE | IOMUXC_PAD_PUS_UP_100K |
        IOMUXC_PAD_HYS | IOMUXC_PAD_ODE);

    /* set outputs to I2C2 */
    /* RI_DTE1 => I2C2_SCLK */
    iomuxc_set_pin_mux(IOMUXC_RI_DTE1,
                       IOMUXC_MUX_OUT_ALT2 | IOMUXC_MUX_IN_ALT2);
    /* DCD_DTE1 => I2C2_SDA */
    iomuxc_set_pin_mux(IOMUXC_DCD_DTE1,
                       IOMUXC_MUX_OUT_ALT2 | IOMUXC_MUX_IN_ALT2);
}

void fmradio_i2c_enable(bool enable)
{
    if (enable)
    {
        /* place in GPIO mode to hold SDIO low during RESET release,
         * SEN1 should be high already (pullup) and GPIO3 left alone */
        bitset32(&GPIO2_GDIR, (1 << 15)); /* SDIO OUT */
        /* I2C2_SDA => MCU2_15 */ 
        iomuxc_set_pin_mux(IOMUXC_DCD_DTE1,
                           IOMUXC_MUX_OUT_GPIO | IOMUXC_MUX_IN_GPIO);
        /* enable CLK32KMCU clock */
        mc13783_set(MC13783_POWER_CONTROL0, MC13783_CLK32KMCUEN);
        /* enable the fm chip (release RESET) */
        bitset32(&GPIO1_DR, (1 << 26));
        sleep(HZ/100);
        /* busmode should be selected - OK to release SDIO */
        bitclr32(&GPIO2_GDIR, (1 << 15)); /* SDIO IN */
        /* restore pin mux (MCU2_15 => I2C2_SDA) */
        iomuxc_set_pin_mux(IOMUXC_DCD_DTE1,
                           IOMUXC_MUX_OUT_ALT2 | IOMUXC_MUX_IN_ALT2);
        /* the si4700 is the only thing connected to i2c2 so
           we can diable the i2c module when not in use */
        i2c_enable_node(&si4700_i2c_node, true);
    }
    else
    {
        /* the si4700 is the only thing connected to i2c2 so
           we can diable the i2c module when not in use */
        i2c_enable_node(&si4700_i2c_node, false);
        /* disable the fm chip */
        bitclr32(&GPIO1_DR, (1 << 26));
        /* disable CLK32KMCU clock */
        mc13783_clear(MC13783_POWER_CONTROL0, MC13783_CLK32KMCUEN);
    }
}

int fmradio_i2c_write(unsigned char address, const unsigned char* buf, int count)
{
    (void)address;
    i2c_write(&si4700_i2c_node, buf, count);
    return 0;
}

int fmradio_i2c_read(unsigned char address, unsigned char* buf, int count)
{
    (void)address;
    i2c_read(&si4700_i2c_node, -1, buf, count);
    return 0;
}

bool si4700_st(void)
{
    return (GPIO1_DR & (1 << 28)) >> 28;
}


/* Low-level RDS Support */
static bool int_restore;

/* Called after I2C read cycle completes */
static void si4700_rds_read_raw_async_callback(struct i2c_transfer_desc *xfer)
{
    if (xfer->rxcount == 0)
        si4700_rds_process();
    /* else read didn't finish */

    if (int_restore)
        gpio_int_enable(SI4700_EVENT_ID);
}

/* Called to read registers from ISR context */
void si4700_rds_read_raw_async(unsigned char *buf, int count)
{
    /* transfer descriptor for RDS async operations */
    static struct i2c_transfer_desc xfer = { .node = &si4700_i2c_node };

    xfer.txdata = NULL;
    xfer.txcount = 0;
    xfer.rxdata = buf;
    xfer.rxcount = count;
    xfer.callback = si4700_rds_read_raw_async_callback;
    xfer.next = NULL;

    i2c_transfer(&xfer);
}

/* RDS GPIO interrupt handler - start RDS data read */
void INT_SI4700_RDS(void)
{
    /* mask and clear the interrupt until we're done */
    gpio_int_disable(SI4700_EVENT_ID);
    gpio_int_clear(SI4700_EVENT_ID);

    /* tell radio driver about it */
    si4700_rds_interrupt();
}

/* Called with on=true after full radio power up, and with on=false before
   powering down */
void si4700_rds_powerup(bool on)
{
    int_restore = on;
    gpio_int_disable(SI4700_EVENT_ID);
    gpio_int_clear(SI4700_EVENT_ID);
    gpio_enable_event(SI4700_EVENT_ID, on);
}

/* One-time RDS init at startup */
void si4700_rds_init(void)
{
    /* nothing to do */
}