diff options
Diffstat (limited to 'arch/arm/cpu/armv7/sunxi/p2wi.c')
| -rw-r--r-- | arch/arm/cpu/armv7/sunxi/p2wi.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv7/sunxi/p2wi.c b/arch/arm/cpu/armv7/sunxi/p2wi.c new file mode 100644 index 0000000000..48613bd0ea --- /dev/null +++ b/arch/arm/cpu/armv7/sunxi/p2wi.c @@ -0,0 +1,117 @@ +/* + * 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 Allwiner A10 SPL work + * + * (C) Copyright 2006-2013 + * Allwinner Technology Co., Ltd. <www.allwinnertech.com> + * Berg Xing <bergxing@allwinnertech.com> + * Tom Cubie <tangliang@allwinnertech.com> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#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 *)SUNXI_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), SUNXI_GPL0_R_P2WI_SCK); + sunxi_gpio_set_cfgpin(SUNXI_GPL(1), SUNXI_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 *)SUNXI_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 *)SUNXI_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 *)SUNXI_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 *)SUNXI_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(); +} |