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/*
* Voltage Controller implementation for OMAP
*
* Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
* Nishanth Menon
*
* 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 "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <common.h>
#include <asm/omap_common.h>
#include <asm/arch/sys_proto.h>
#include <asm/arch/clock.h>
/* Register defines and masks for VC IP Block */
/* PRM_VC_CFG_I2C_MODE */
#define PRM_VC_CFG_I2C_MODE_DFILTEREN_BIT (0x1 << 6)
#define PRM_VC_CFG_I2C_MODE_SRMODEEN_BIT (0x1 << 4)
#define PRM_VC_CFG_I2C_MODE_HSMODEEN_BIT (0x1 << 3)
#define PRM_VC_CFG_I2C_MODE_HSMCODE_SHIFT 0x0
#define PRM_VC_CFG_I2C_MODE_HSMCODE_MASK 0x3
/* PRM_VC_CFG_I2C_CLK */
#define PRM_VC_CFG_I2C_CLK_HSCLL_SHIFT 24
#define PRM_VC_CFG_I2C_CLK_HSCLL_MASK 0xFF
#define PRM_VC_CFG_I2C_CLK_HSCLH_SHIFT 16
#define PRM_VC_CFG_I2C_CLK_HSCLH_MASK 0xFF
#define PRM_VC_CFG_I2C_CLK_SCLH_SHIFT 0
#define PRM_VC_CFG_I2C_CLK_SCLH_MASK 0xFF
#define PRM_VC_CFG_I2C_CLK_SCLL_SHIFT 8
#define PRM_VC_CFG_I2C_CLK_SCLL_MASK (0xFF << 8)
/* PRM_VC_VAL_BYPASS */
#define PRM_VC_VAL_BYPASS_VALID_BIT (0x1 << 24)
#define PRM_VC_VAL_BYPASS_SLAVEADDR_SHIFT 0
#define PRM_VC_VAL_BYPASS_SLAVEADDR_MASK 0x7F
#define PRM_VC_VAL_BYPASS_REGADDR_SHIFT 8
#define PRM_VC_VAL_BYPASS_REGADDR_MASK 0xFF
#define PRM_VC_VAL_BYPASS_DATA_SHIFT 16
#define PRM_VC_VAL_BYPASS_DATA_MASK 0xFF
/**
* omap_vc_init() - Initialization for Voltage controller
* @speed_khz: I2C buspeed in KHz
*/
static void omap_vc_init(u16 speed_khz)
{
u32 val;
u32 sys_clk_khz, cycles_hi, cycles_low;
sys_clk_khz = get_sys_clk_freq() / 1000;
if (speed_khz > 400) {
puts("higher speed requested - throttle to 400Khz\n");
speed_khz = 400;
}
/*
* Setup the dedicated I2C controller for Voltage Control
* I2C clk - high period 40% low period 60%
*/
speed_khz /= 10;
cycles_hi = sys_clk_khz * 4 / speed_khz;
cycles_low = sys_clk_khz * 6 / speed_khz;
/* values to be set in register - less by 5 & 7 respectively */
cycles_hi -= 5;
cycles_low -= 7;
val = (cycles_hi << PRM_VC_CFG_I2C_CLK_SCLH_SHIFT) |
(cycles_low << PRM_VC_CFG_I2C_CLK_SCLL_SHIFT);
writel(val, (*prcm)->prm_vc_cfg_i2c_clk);
/*
* Master code if there are multiple masters on the I2C_SR bus.
*/
val = 0x0 << PRM_VC_CFG_I2C_MODE_HSMCODE_SHIFT;
/* No HS mode for now */
val &= ~PRM_VC_CFG_I2C_MODE_HSMODEEN_BIT;
writel(val, (*prcm)->prm_vc_cfg_i2c_mode);
}
/**
* omap_vc_bypass_send_value() - Send a data using VC Bypass command
* @sa: 7 bit I2C slave address of the PMIC
* @reg_addr: I2C register address(8 bit) address in PMIC
* @reg_data: what 8 bit data to write
*/
int omap_vc_bypass_send_value(u8 sa, u8 reg_addr, u8 reg_data)
{
/*
* Unfortunately we need to loop here instead of a defined time
* use arbitary large value
*/
u32 timeout = 0xFFFF;
u32 reg_val;
sa &= PRM_VC_VAL_BYPASS_SLAVEADDR_MASK;
reg_addr &= PRM_VC_VAL_BYPASS_REGADDR_MASK;
reg_data &= PRM_VC_VAL_BYPASS_DATA_MASK;
/* program VC to send data */
reg_val = sa << PRM_VC_VAL_BYPASS_SLAVEADDR_SHIFT |
reg_addr << PRM_VC_VAL_BYPASS_REGADDR_SHIFT |
reg_data << PRM_VC_VAL_BYPASS_DATA_SHIFT;
writel(reg_val, (*prcm)->prm_vc_val_bypass);
/* Signal VC to send data */
writel(reg_val | PRM_VC_VAL_BYPASS_VALID_BIT,
(*prcm)->prm_vc_val_bypass);
/* Wait on VC to complete transmission */
do {
reg_val = readl((*prcm)->prm_vc_val_bypass) &
PRM_VC_VAL_BYPASS_VALID_BIT;
if (!reg_val)
break;
sdelay(100);
} while (--timeout);
/* Optional: cleanup PRM_IRQSTATUS_Ax */
/* In case we can do something about it in future.. */
if (!timeout)
return -1;
/* All good.. */
return 0;
}
void sri2c_init(void)
{
static int sri2c = 1;
if (sri2c) {
omap_vc_init(PRM_VC_I2C_CHANNEL_FREQ_KHZ);
sri2c = 0;
}
return;
}