u-boot/arch/arm/mach-sunxi/p2wi.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Sunxi A31 Power Management Unit
*
* (C) Copyright 2013 Oliver Schinagl <oliver@schinagl.nl>
* http://linux-sunxi.org
*
* Based on sun6i sources and earlier U-Boot Allwinner A10 SPL work
*
* (C) Copyright 2006-2013
* Allwinner Technology Co., Ltd. <www.allwinnertech.com>
* Berg Xing <bergxing@allwinnertech.com>
* Tom Cubie <tangliang@allwinnertech.com>
*/
#include <common.h>
#include <errno.h>
#include <asm/io.h>
#include <asm/arch/cpu.h>
#include <asm/arch/gpio.h>
#include <asm/arch/p2wi.h>
#include <asm/arch/prcm.h>
#include <asm/arch/clock.h>
#include <asm/arch/sys_proto.h>
void p2wi_init(void)
{
struct sunxi_p2wi_reg *p2wi = (struct sunxi_p2wi_reg *)SUN6I_P2WI_BASE;
/* Enable p2wi and PIO clk, and de-assert their resets */
prcm_apb0_enable(PRCM_APB0_GATE_PIO | PRCM_APB0_GATE_P2WI);
sunxi_gpio_set_cfgpin(SUNXI_GPL(0), SUN6I_GPL0_R_P2WI_SCK);
sunxi_gpio_set_cfgpin(SUNXI_GPL(1), SUN6I_GPL1_R_P2WI_SDA);
/* Reset p2wi controller and set clock to CLKIN(12)/8 = 1.5 MHz */
writel(P2WI_CTRL_RESET, &p2wi->ctrl);
sdelay(0x100);
writel(P2WI_CC_SDA_OUT_DELAY(1) | P2WI_CC_CLK_DIV(8),
&p2wi->cc);
}
int p2wi_change_to_p2wi_mode(u8 slave_addr, u8 ctrl_reg, u8 init_data)
{
struct sunxi_p2wi_reg *p2wi = (struct sunxi_p2wi_reg *)SUN6I_P2WI_BASE;
unsigned long tmo = timer_get_us() + 1000000;
writel(P2WI_PM_DEV_ADDR(slave_addr) |
P2WI_PM_CTRL_ADDR(ctrl_reg) |
P2WI_PM_INIT_DATA(init_data) |
P2WI_PM_INIT_SEND,
&p2wi->pm);
while ((readl(&p2wi->pm) & P2WI_PM_INIT_SEND)) {
if (timer_get_us() > tmo)
return -ETIME;
}
return 0;
}
static int p2wi_await_trans(void)
{
struct sunxi_p2wi_reg *p2wi = (struct sunxi_p2wi_reg *)SUN6I_P2WI_BASE;
unsigned long tmo = timer_get_us() + 1000000;
int ret;
u8 reg;
while (1) {
reg = readl(&p2wi->status);
if (reg & P2WI_STAT_TRANS_ERR) {
ret = -EIO;
break;
}
if (reg & P2WI_STAT_TRANS_DONE) {
ret = 0;
break;
}
if (timer_get_us() > tmo) {
ret = -ETIME;
break;
}
}
writel(reg, &p2wi->status); /* Clear status bits */
return ret;
}
int p2wi_read(const u8 addr, u8 *data)
{
struct sunxi_p2wi_reg *p2wi = (struct sunxi_p2wi_reg *)SUN6I_P2WI_BASE;
int ret;
writel(P2WI_DATADDR_BYTE_1(addr), &p2wi->dataddr0);
writel(P2WI_DATA_NUM_BYTES(1) |
P2WI_DATA_NUM_BYTES_READ, &p2wi->numbytes);
writel(P2WI_STAT_TRANS_DONE, &p2wi->status);
writel(P2WI_CTRL_TRANS_START, &p2wi->ctrl);
ret = p2wi_await_trans();
*data = readl(&p2wi->data0) & P2WI_DATA_BYTE_1_MASK;
return ret;
}
int p2wi_write(const u8 addr, u8 data)
{
struct sunxi_p2wi_reg *p2wi = (struct sunxi_p2wi_reg *)SUN6I_P2WI_BASE;
writel(P2WI_DATADDR_BYTE_1(addr), &p2wi->dataddr0);
writel(P2WI_DATA_BYTE_1(data), &p2wi->data0);
writel(P2WI_DATA_NUM_BYTES(1), &p2wi->numbytes);
writel(P2WI_STAT_TRANS_DONE, &p2wi->status);
writel(P2WI_CTRL_TRANS_START, &p2wi->ctrl);
return p2wi_await_trans();
}