arch/arm/mach-sunxi/p2wi.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Sunxi A31 Power Management Unit
   4  *
   5  * (C) Copyright 2013 Oliver Schinagl <oliver@schinagl.nl>
   6  * http://linux-sunxi.org
   7  *
   8  * Based on sun6i sources and earlier U-Boot Allwiner A10 SPL work
   9  *
  10  * (C) Copyright 2006-2013
  11  * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
  12  * Berg Xing <bergxing@allwinnertech.com>
  13  * Tom Cubie <tangliang@allwinnertech.com>
  14  */
  15
  16 #include <common.h>
  17 #include <errno.h>
  18 #include <asm/io.h>
  19 #include <asm/arch/cpu.h>
  20 #include <asm/arch/gpio.h>
  21 #include <asm/arch/p2wi.h>
  22 #include <asm/arch/prcm.h>
  23 #include <asm/arch/clock.h>
  24 #include <asm/arch/sys_proto.h>
  25
  26 void p2wi_init(void)
  27 {
  28         struct sunxi_p2wi_reg *p2wi = (struct sunxi_p2wi_reg *)SUN6I_P2WI_BASE;
  29
  30         /* Enable p2wi and PIO clk, and de-assert their resets */
  31         prcm_apb0_enable(PRCM_APB0_GATE_PIO | PRCM_APB0_GATE_P2WI);
  32
  33         sunxi_gpio_set_cfgpin(SUNXI_GPL(0), SUN6I_GPL0_R_P2WI_SCK);
  34         sunxi_gpio_set_cfgpin(SUNXI_GPL(1), SUN6I_GPL1_R_P2WI_SDA);
  35
  36         /* Reset p2wi controller and set clock to CLKIN(12)/8 = 1.5 MHz */
  37         writel(P2WI_CTRL_RESET, &p2wi->ctrl);
  38         sdelay(0x100);
  39         writel(P2WI_CC_SDA_OUT_DELAY(1) | P2WI_CC_CLK_DIV(8),
  40                &p2wi->cc);
  41 }
  42
  43 int p2wi_change_to_p2wi_mode(u8 slave_addr, u8 ctrl_reg, u8 init_data)
  44 {
  45         struct sunxi_p2wi_reg *p2wi = (struct sunxi_p2wi_reg *)SUN6I_P2WI_BASE;
  46         unsigned long tmo = timer_get_us() + 1000000;
  47
  48         writel(P2WI_PM_DEV_ADDR(slave_addr) |
  49                P2WI_PM_CTRL_ADDR(ctrl_reg) |
  50                P2WI_PM_INIT_DATA(init_data) |
  51                P2WI_PM_INIT_SEND,
  52                &p2wi->pm);
  53
  54         while ((readl(&p2wi->pm) & P2WI_PM_INIT_SEND)) {
  55                 if (timer_get_us() > tmo)
  56                         return -ETIME;
  57         }
  58
  59         return 0;
  60 }
  61
  62 static int p2wi_await_trans(void)
  63 {
  64         struct sunxi_p2wi_reg *p2wi = (struct sunxi_p2wi_reg *)SUN6I_P2WI_BASE;
  65         unsigned long tmo = timer_get_us() + 1000000;
  66         int ret;
  67         u8 reg;
  68
  69         while (1) {
  70                 reg = readl(&p2wi->status);
  71                 if (reg & P2WI_STAT_TRANS_ERR) {
  72                         ret = -EIO;
  73                         break;
  74                 }
  75                 if (reg & P2WI_STAT_TRANS_DONE) {
  76                         ret = 0;
  77                         break;
  78                 }
  79                 if (timer_get_us() > tmo) {
  80                         ret = -ETIME;
  81                         break;
  82                 }
  83         }
  84         writel(reg, &p2wi->status); /* Clear status bits */
  85         return ret;
  86 }
  87
  88 int p2wi_read(const u8 addr, u8 *data)
  89 {
  90         struct sunxi_p2wi_reg *p2wi = (struct sunxi_p2wi_reg *)SUN6I_P2WI_BASE;
  91         int ret;
  92
  93         writel(P2WI_DATADDR_BYTE_1(addr), &p2wi->dataddr0);
  94         writel(P2WI_DATA_NUM_BYTES(1) |
  95                P2WI_DATA_NUM_BYTES_READ, &p2wi->numbytes);
  96         writel(P2WI_STAT_TRANS_DONE, &p2wi->status);
  97         writel(P2WI_CTRL_TRANS_START, &p2wi->ctrl);
  98
  99         ret = p2wi_await_trans();
 100
 101         *data = readl(&p2wi->data0) & P2WI_DATA_BYTE_1_MASK;
 102         return ret;
 103 }
 104
 105 int p2wi_write(const u8 addr, u8 data)
 106 {
 107         struct sunxi_p2wi_reg *p2wi = (struct sunxi_p2wi_reg *)SUN6I_P2WI_BASE;
 108
 109         writel(P2WI_DATADDR_BYTE_1(addr), &p2wi->dataddr0);
 110         writel(P2WI_DATA_BYTE_1(data), &p2wi->data0);
 111         writel(P2WI_DATA_NUM_BYTES(1), &p2wi->numbytes);
 112         writel(P2WI_STAT_TRANS_DONE, &p2wi->status);
 113         writel(P2WI_CTRL_TRANS_START, &p2wi->ctrl);
 114
 115         return p2wi_await_trans();
 116 }