u-boot/arch/arm/cpu/armv7/u8500/prcmu.c

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/*
* Copyright (C) 2009 ST-Ericsson SA
*
* Adapted from the Linux version:
* Author: Kumar Sanghvi <kumar.sanghvi@stericsson.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
/*
* NOTE: This currently does not support the I2C workaround access method.
*/
#include <common.h>
#include <config.h>
#include <asm/io.h>
#include <asm/arch/hardware.h>
#include <asm/types.h>
#include <asm/io.h>
#include <asm/errno.h>
#include <asm/arch/prcmu.h>
/* CPU mailbox registers */
#define PRCMU_I2C_WRITE(slave) \
(((slave) << 1) | I2CWRITE | (1 << 6))
#define PRCMU_I2C_READ(slave) \
(((slave) << 1) | I2CREAD | (1 << 6))
#define I2C_MBOX_BIT (1 << 5)
static int prcmu_is_ready(void)
{
int ready = readb(PRCM_XP70_CUR_PWR_STATE) == AP_EXECUTE;
if (!ready)
printf("PRCMU firmware not ready\n");
return ready;
}
static int wait_for_i2c_mbx_rdy(void)
{
int timeout = 10000;
if (readl(PRCM_ARM_IT1_VAL) & I2C_MBOX_BIT) {
printf("prcmu: warning i2c mailbox was not acked\n");
/* clear mailbox 5 ack irq */
writel(I2C_MBOX_BIT, PRCM_ARM_IT1_CLEAR);
}
/* check any already on-going transaction */
while ((readl(PRCM_MBOX_CPU_VAL) & I2C_MBOX_BIT) && timeout)
timeout--;
if (timeout == 0)
return -1;
return 0;
}
static int wait_for_i2c_req_done(void)
{
int timeout = 10000;
/* Set an interrupt to XP70 */
writel(I2C_MBOX_BIT, PRCM_MBOX_CPU_SET);
/* wait for mailbox 5 (i2c) ack */
while (!(readl(PRCM_ARM_IT1_VAL) & I2C_MBOX_BIT) && timeout)
timeout--;
if (timeout == 0)
return -1;
return 0;
}
/**
* prcmu_i2c_read - PRCMU - 4500 communication using PRCMU I2C
* @reg: - db8500 register bank to be accessed
* @slave: - db8500 register to be accessed
* Returns: ACK_MB5 value containing the status
*/
int prcmu_i2c_read(u8 reg, u16 slave)
{
uint8_t i2c_status;
uint8_t i2c_val;
int ret;
if (!prcmu_is_ready())
return -1;
debug("\nprcmu_4500_i2c_read:bank=%x;reg=%x;\n",
reg, slave);
ret = wait_for_i2c_mbx_rdy();
if (ret) {
printf("prcmu_i2c_read: mailbox became not ready\n");
return ret;
}
/* prepare the data for mailbox 5 */
writeb(PRCMU_I2C_READ(reg), PRCM_REQ_MB5_I2COPTYPE_REG);
writeb((1 << 3) | 0x0, PRCM_REQ_MB5_BIT_FIELDS);
writeb(slave, PRCM_REQ_MB5_I2CSLAVE);
writeb(0, PRCM_REQ_MB5_I2CVAL);
ret = wait_for_i2c_req_done();
if (ret) {
printf("prcmu_i2c_read: mailbox request timed out\n");
return ret;
}
/* retrieve values */
debug("ack-mb5:transfer status = %x\n",
readb(PRCM_ACK_MB5_STATUS));
debug("ack-mb5:reg bank = %x\n", readb(PRCM_ACK_MB5) >> 1);
debug("ack-mb5:slave_add = %x\n",
readb(PRCM_ACK_MB5_SLAVE));
debug("ack-mb5:reg_val = %d\n", readb(PRCM_ACK_MB5_VAL));
i2c_status = readb(PRCM_ACK_MB5_STATUS);
i2c_val = readb(PRCM_ACK_MB5_VAL);
/* clear mailbox 5 ack irq */
writel(I2C_MBOX_BIT, PRCM_ARM_IT1_CLEAR);
if (i2c_status == I2C_RD_OK)
return i2c_val;
printf("prcmu_i2c_read:read return status= %d\n", i2c_status);
return -1;
}
/**
* prcmu_i2c_write - PRCMU-db8500 communication using PRCMU I2C
* @reg: - db8500 register bank to be accessed
* @slave: - db800 register to be written to
* @reg_data: - the data to write
* Returns: ACK_MB5 value containing the status
*/
int prcmu_i2c_write(u8 reg, u16 slave, u8 reg_data)
{
uint8_t i2c_status;
int ret;
if (!prcmu_is_ready())
return -1;
debug("\nprcmu_4500_i2c_write:bank=%x;reg=%x;\n",
reg, slave);
ret = wait_for_i2c_mbx_rdy();
if (ret) {
printf("prcmu_i2c_write: mailbox became not ready\n");
return ret;
}
/* prepare the data for mailbox 5 */
writeb(PRCMU_I2C_WRITE(reg), PRCM_REQ_MB5_I2COPTYPE_REG);
writeb((1 << 3) | 0x0, PRCM_REQ_MB5_BIT_FIELDS);
writeb(slave, PRCM_REQ_MB5_I2CSLAVE);
writeb(reg_data, PRCM_REQ_MB5_I2CVAL);
ret = wait_for_i2c_req_done();
if (ret) {
printf("prcmu_i2c_write: mailbox request timed out\n");
return ret;
}
/* retrieve values */
debug("ack-mb5:transfer status = %x\n",
readb(PRCM_ACK_MB5_STATUS));
debug("ack-mb5:reg bank = %x\n", readb(PRCM_ACK_MB5) >> 1);
debug("ack-mb5:slave_add = %x\n",
readb(PRCM_ACK_MB5_SLAVE));
debug("ack-mb5:reg_val = %d\n", readb(PRCM_ACK_MB5_VAL));
i2c_status = readb(PRCM_ACK_MB5_STATUS);
debug("\ni2c_status = %x\n", i2c_status);
/* clear mailbox 5 ack irq */
writel(I2C_MBOX_BIT, PRCM_ARM_IT1_CLEAR);
if (i2c_status == I2C_WR_OK)
return 0;
printf("%s: i2c_status : 0x%x\n", __func__, i2c_status);
return -1;
}
void u8500_prcmu_enable(u32 *reg)
{
writel(readl(reg) | (1 << 8), reg);
}
void db8500_prcmu_init(void)
{
/* Enable timers */
writel(1 << 17, PRCM_TCR);
u8500_prcmu_enable((u32 *)PRCM_PER1CLK_MGT_REG);
u8500_prcmu_enable((u32 *)PRCM_PER2CLK_MGT_REG);
u8500_prcmu_enable((u32 *)PRCM_PER3CLK_MGT_REG);
/* PER4CLK does not exist */
u8500_prcmu_enable((u32 *)PRCM_PER5CLK_MGT_REG);
u8500_prcmu_enable((u32 *)PRCM_PER6CLK_MGT_REG);
/* Only exists in ED but is always ok to write to */
u8500_prcmu_enable((u32 *)PRCM_PER7CLK_MGT_REG);
u8500_prcmu_enable((u32 *)PRCM_UARTCLK_MGT_REG);
u8500_prcmu_enable((u32 *)PRCM_I2CCLK_MGT_REG);
u8500_prcmu_enable((u32 *)PRCM_SDMMCCLK_MGT_REG);
/* Clean up the mailbox interrupts after pre-u-boot code. */
writel(I2C_MBOX_BIT, PRCM_ARM_IT1_CLEAR);
}