summaryrefslogtreecommitdiff
path: root/arch/arm/cpu/armv7/sunxi/rsb.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/cpu/armv7/sunxi/rsb.c')
-rw-r--r--arch/arm/cpu/armv7/sunxi/rsb.c158
1 files changed, 158 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv7/sunxi/rsb.c b/arch/arm/cpu/armv7/sunxi/rsb.c
new file mode 100644
index 0000000..b72bb9d
--- /dev/null
+++ b/arch/arm/cpu/armv7/sunxi/rsb.c
@@ -0,0 +1,158 @@
+/*
+ * (C) Copyright 2014 Hans de Goede <hdegoede@redhat.com>
+ *
+ * Based on allwinner u-boot sources rsb code which is:
+ * (C) Copyright 2007-2013
+ * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
+ * lixiang <lixiang@allwinnertech.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <asm/arch/cpu.h>
+#include <asm/arch/gpio.h>
+#include <asm/arch/prcm.h>
+#include <asm/arch/rsb.h>
+
+static void rsb_cfg_io(void)
+{
+ sunxi_gpio_set_cfgpin(SUNXI_GPL(0), SUN8I_GPL0_R_RSB_SCK);
+ sunxi_gpio_set_cfgpin(SUNXI_GPL(1), SUN8I_GPL1_R_RSB_SDA);
+ sunxi_gpio_set_pull(SUNXI_GPL(0), 1);
+ sunxi_gpio_set_pull(SUNXI_GPL(1), 1);
+ sunxi_gpio_set_drv(SUNXI_GPL(0), 2);
+ sunxi_gpio_set_drv(SUNXI_GPL(1), 2);
+}
+
+static void rsb_set_clk(void)
+{
+ struct sunxi_rsb_reg * const rsb =
+ (struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
+ u32 div = 0;
+ u32 cd_odly = 0;
+
+ /* Source is Hosc24M, set RSB clk to 3Mhz */
+ div = 24000000 / 3000000 / 2 - 1;
+ cd_odly = div >> 1;
+ if (!cd_odly)
+ cd_odly = 1;
+
+ writel((cd_odly << 8) | div, &rsb->ccr);
+}
+
+void rsb_init(void)
+{
+ struct sunxi_rsb_reg * const rsb =
+ (struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
+
+ rsb_cfg_io();
+
+ /* Enable RSB and PIO clk, and de-assert their resets */
+ prcm_apb0_enable(PRCM_APB0_GATE_PIO | PRCM_APB0_GATE_RSB);
+
+ writel(RSB_CTRL_SOFT_RST, &rsb->ctrl);
+ rsb_set_clk();
+}
+
+static int rsb_await_trans(void)
+{
+ struct sunxi_rsb_reg * const rsb =
+ (struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
+ unsigned long tmo = timer_get_us() + 1000000;
+ u32 stat;
+ int ret;
+
+ while (1) {
+ stat = readl(&rsb->stat);
+ if (stat & RSB_STAT_LBSY_INT) {
+ ret = -EBUSY;
+ break;
+ }
+ if (stat & RSB_STAT_TERR_INT) {
+ ret = -EIO;
+ break;
+ }
+ if (stat & RSB_STAT_TOVER_INT) {
+ ret = 0;
+ break;
+ }
+ if (timer_get_us() > tmo) {
+ ret = -ETIME;
+ break;
+ }
+ }
+ writel(stat, &rsb->stat); /* Clear status bits */
+
+ return ret;
+}
+
+int rsb_set_device_mode(u32 device_mode_data)
+{
+ struct sunxi_rsb_reg * const rsb =
+ (struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
+ unsigned long tmo = timer_get_us() + 1000000;
+
+ writel(RSB_DMCR_DEVICE_MODE_START | device_mode_data, &rsb->dmcr);
+
+ while (readl(&rsb->dmcr) & RSB_DMCR_DEVICE_MODE_START) {
+ if (timer_get_us() > tmo)
+ return -ETIME;
+ }
+
+ return rsb_await_trans();
+}
+
+static int rsb_do_trans(void)
+{
+ struct sunxi_rsb_reg * const rsb =
+ (struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
+
+ setbits_le32(&rsb->ctrl, RSB_CTRL_START_TRANS);
+ return rsb_await_trans();
+}
+
+int rsb_set_device_address(u16 device_addr, u16 runtime_addr)
+{
+ struct sunxi_rsb_reg * const rsb =
+ (struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
+
+ writel(RSB_DEVADDR_RUNTIME_ADDR(runtime_addr) |
+ RSB_DEVADDR_DEVICE_ADDR(device_addr), &rsb->devaddr);
+ writel(RSB_CMD_SET_RTSADDR, &rsb->cmd);
+
+ return rsb_do_trans();
+}
+
+int rsb_write(const u16 runtime_device_addr, const u8 reg_addr, u8 data)
+{
+ struct sunxi_rsb_reg * const rsb =
+ (struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
+
+ writel(RSB_DEVADDR_RUNTIME_ADDR(runtime_device_addr), &rsb->devaddr);
+ writel(reg_addr, &rsb->addr);
+ writel(data, &rsb->data);
+ writel(RSB_CMD_BYTE_WRITE, &rsb->cmd);
+
+ return rsb_do_trans();
+}
+
+int rsb_read(const u16 runtime_device_addr, const u8 reg_addr, u8 *data)
+{
+ struct sunxi_rsb_reg * const rsb =
+ (struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
+ int ret;
+
+ writel(RSB_DEVADDR_RUNTIME_ADDR(runtime_device_addr), &rsb->devaddr);
+ writel(reg_addr, &rsb->addr);
+ writel(RSB_CMD_BYTE_READ, &rsb->cmd);
+
+ ret = rsb_do_trans();
+ if (ret)
+ return ret;
+
+ *data = readl(&rsb->data) & 0xff;
+
+ return 0;
+}