[U-Boot] [PATCH 02/14] sunxi: Add support for the rsb (Reduced Serial Bus)

Chen-Yu Tsai wens at csie.org
Wed Dec 17 03:22:14 CET 2014


Hi,

On Wed, Dec 17, 2014 at 4:31 AM, Hans de Goede <hdegoede at redhat.com> wrote:
> sun8i (A23) introduces a new bus for communicating with the pmic, the rsb,
> the rsb is also used to communicate with the pmic on the A80, and is
> documented in the A80 user manual.
>
> This commit adds support for this based on the rsb driver from the allwinner
> u-boot sources.
>
> Note: Not yet ready for upstream, code needs some significant cleanups.

Confusing note.

>
> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
> ---
>  arch/arm/cpu/armv7/sunxi/Makefile      |   1 +
>  arch/arm/cpu/armv7/sunxi/rsb.c         | 158 +++++++++++++++++++++++++++++++++
>  arch/arm/include/asm/arch-sunxi/cpu.h  |   3 +-
>  arch/arm/include/asm/arch-sunxi/gpio.h |   2 +
>  arch/arm/include/asm/arch-sunxi/prcm.h |   3 +-
>  arch/arm/include/asm/arch-sunxi/rsb.h  |  55 ++++++++++++
>  6 files changed, 220 insertions(+), 2 deletions(-)
>  create mode 100644 arch/arm/cpu/armv7/sunxi/rsb.c
>  create mode 100644 arch/arm/include/asm/arch-sunxi/rsb.h
>
> diff --git a/arch/arm/cpu/armv7/sunxi/Makefile b/arch/arm/cpu/armv7/sunxi/Makefile
> index 1337b60..3e8975a 100644
> --- a/arch/arm/cpu/armv7/sunxi/Makefile
> +++ b/arch/arm/cpu/armv7/sunxi/Makefile
> @@ -15,6 +15,7 @@ obj-y += pinmux.o
>  obj-$(CONFIG_MACH_SUN6I)       += prcm.o
>  obj-$(CONFIG_MACH_SUN8I)       += prcm.o
>  obj-$(CONFIG_MACH_SUN6I)       += p2wi.o
> +obj-$(CONFIG_MACH_SUN8I)       += rsb.o
>  obj-$(CONFIG_MACH_SUN4I)       += clock_sun4i.o
>  obj-$(CONFIG_MACH_SUN5I)       += clock_sun4i.o
>  obj-$(CONFIG_MACH_SUN6I)       += clock_sun6i.o
> 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 at 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 at 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);

Do we need a small delay here for the device to finish reset?

> +       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;
> +}
> diff --git a/arch/arm/include/asm/arch-sunxi/cpu.h b/arch/arm/include/asm/arch-sunxi/cpu.h
> index 9500262..49c1614 100644
> --- a/arch/arm/include/asm/arch-sunxi/cpu.h
> +++ b/arch/arm/include/asm/arch-sunxi/cpu.h
> @@ -128,7 +128,8 @@
>  #define SUN6I_CPUCFG_BASE              0x01f01c00
>  #define SUNXI_R_UART_BASE              0x01f02800
>  #define SUNXI_R_PIO_BASE               0x01f02c00
> -#define SUNXI_P2WI_BASE                        0x01f03400
> +#define SUNXI_P2WI_BASE                        0x01f03400      /* on sun6i */
> +#define SUNXI_RSB_BASE                 0x01f03400      /* on sun8i */

Maybe we just use SUN6I_ SUN8I_ prefixes?
The base address will be different on sun9i.

>
>  /* CoreSight Debug Module */
>  #define SUNXI_CSDM_BASE                        0x3f500000
> diff --git a/arch/arm/include/asm/arch-sunxi/gpio.h b/arch/arm/include/asm/arch-sunxi/gpio.h
> index 9f972ce..6623f15 100644
> --- a/arch/arm/include/asm/arch-sunxi/gpio.h
> +++ b/arch/arm/include/asm/arch-sunxi/gpio.h
> @@ -176,6 +176,8 @@ enum sunxi_gpio_number {
>  #define SUN6I_GPL0_R_P2WI_SCK  3
>  #define SUN6I_GPL1_R_P2WI_SDA  3
>
> +#define SUN8I_GPL0_R_RSB_SCK   2
> +#define SUN8I_GPL1_R_RSB_SDA   2
>  #define SUN8I_GPL2_R_UART_TX   2
>  #define SUN8I_GPL3_R_UART_RX   2
>
> diff --git a/arch/arm/include/asm/arch-sunxi/prcm.h b/arch/arm/include/asm/arch-sunxi/prcm.h
> index 88de1ff..82ed541 100644
> --- a/arch/arm/include/asm/arch-sunxi/prcm.h
> +++ b/arch/arm/include/asm/arch-sunxi/prcm.h
> @@ -50,7 +50,8 @@
>  #define PRCM_APB0_GATE_PIO (0x1 << 0)
>  #define PRCM_APB0_GATE_IR (0x1 << 1)
>  #define PRCM_APB0_GATE_TIMER01 (0x1 << 2)
> -#define PRCM_APB0_GATE_P2WI (0x1 << 3)
> +#define PRCM_APB0_GATE_P2WI (0x1 << 3)         /* sun6i */
> +#define PRCM_APB0_GATE_RSB (0x1 << 3)          /* sun8i */
>  #define PRCM_APB0_GATE_UART (0x1 << 4)
>  #define PRCM_APB0_GATE_1WIRE (0x1 << 5)
>  #define PRCM_APB0_GATE_I2C (0x1 << 6)
> diff --git a/arch/arm/include/asm/arch-sunxi/rsb.h b/arch/arm/include/asm/arch-sunxi/rsb.h
> new file mode 100644
> index 0000000..95a595a
> --- /dev/null
> +++ b/arch/arm/include/asm/arch-sunxi/rsb.h
> @@ -0,0 +1,55 @@
> +/*
> + * (C) Copyright 2014 Hans de Goede <hdegoede at 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 at allwinnertech.com>
> + *
> + * SPDX-License-Identifier:    GPL-2.0+
> + */
> +
> +#ifndef __SUNXI_RSB_H
> +#define __SUNXI_RSB_H
> +
> +#include <common.h>
> +#include <asm/io.h>
> +
> +struct sunxi_rsb_reg {
> +       u32 ctrl;       /* 0x00 */
> +       u32 ccr;        /* 0x04 */
> +       u32 inte;       /* 0x08 */
> +       u32 stat;       /* 0x0c */
> +       u32 addr;       /* 0x10 */
> +       u8 res0[8];     /* 0x14 */
> +       u32 data;       /* 0x1c */
> +       u8 res1[4];     /* 0x20 */
> +       u32 lcr;        /* 0x24 */
> +       u32 dmcr;       /* 0x28 */
> +       u32 cmd;        /* 0x2c */
> +       u32 devaddr;    /* 0x30 */
> +};
> +
> +#define RSB_CTRL_SOFT_RST              (1 << 0)
> +#define RSB_CTRL_START_TRANS           (1 << 7)
> +
> +#define RSB_STAT_TOVER_INT             (1 << 0)
> +#define RSB_STAT_TERR_INT              (1 << 1)
> +#define RSB_STAT_LBSY_INT              (1 << 2)
> +
> +#define RSB_DMCR_DEVICE_MODE_START     (1 << 31)
> +
> +#define RSB_CMD_BYTE_WRITE             0x4e
> +#define RSB_CMD_BYTE_READ              0x8b
> +#define RSB_CMD_SET_RTSADDR            0xe8
> +
> +#define RSB_DEVADDR_RUNTIME_ADDR(x)    ((x) << 16)
> +#define RSB_DEVADDR_DEVICE_ADDR(x)     ((x) << 0)
> +
> +void rsb_init(void);
> +int rsb_set_device_mode(u32 device_mode_data);
> +int rsb_set_device_address(u16 device_addr, u16 runtime_addr);
> +int rsb_write(const u16 runtime_device_addr, const u8 reg_addr, u8 data);
> +int rsb_read(const u16 runtime_device_addr, const u8 reg_addr, u8 *data);
> +
> +#endif
> --
> 2.1.0

The rest looks good. Thanks!

ChenYu


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