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

Chen-Yu Tsai
2014-12-17T02:22:14Z

Hi,

On Wed, Dec 17, 2014 at 4:31 AM, Hans de Goede <hdegoede@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@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@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);

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@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+
> + */
> +
> +#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