linux-imx

/*

 * Core driver for STw4810/STw4811

 *

 * Copyright (C) 2013 ST-Ericsson SA

 * Written on behalf of Linaro for ST-Ericsson

 *

 * Author: Linus Walleij <linus.walleij@linaro.org>

 *

 * License terms: GNU General Public License (GPL) version 2

 */

​

#include <linux/err.h>

#include <linux/i2c.h>

#include <linux/init.h>

#include <linux/mfd/core.h>

#include <linux/mfd/stw481x.h>

#include <linux/module.h>

#include <linux/regmap.h>

#include <linux/spinlock.h>

#include <linux/slab.h>

​

/*

 * This driver can only access the non-USB portions of STw4811, the register

 * range 0x00-0x10 dealing with USB is bound to the two special I2C pins used

 * for USB control.

 */

​

/* Registers inside the power control address space */

#define STW_PC_VCORE_SEL    0x05U

#define STW_PC_VAUX_SEL     0x06U

#define STW_PC_VPLL_SEL     0x07U

​

/**

 * stw481x_get_pctl_reg() - get a power control register

 * @stw481x: handle to the stw481x chip

 * @reg: power control register to fetch

 *

 * The power control registers is a set of one-time-programmable registers

 * in its own register space, accessed by writing addess bits to these

 * two registers: bits 7,6,5 of PCTL_REG_LO corresponds to the 3 LSBs of

 * the address and bits 8,9 of PCTL_REG_HI corresponds to the 2 MSBs of

 * the address, forming an address space of 5 bits, i.e. 32 registers

 * 0x00 ... 0x1f can be obtained.

 */

static int stw481x_get_pctl_reg(struct stw481x *stw481x, u8 reg)

{

    u8 msb = (reg >> 3) & 0x03;

    u8 lsb = (reg << 5) & 0xe0;

    unsigned int val;

    u8 vrfy;

    int ret;

​

    ret = regmap_write(stw481x->map, STW_PCTL_REG_HI, msb);

    if (ret)

        return ret;

    ret = regmap_write(stw481x->map, STW_PCTL_REG_LO, lsb);

    if (ret)

        return ret;

    ret = regmap_read(stw481x->map, STW_PCTL_REG_HI, &val);

    if (ret)

        return ret;

    vrfy = (val & 0x03) << 3;

    ret = regmap_read(stw481x->map, STW_PCTL_REG_LO, &val);