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

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 17-12-14 03:22, Chen-Yu Tsai wrote:
> 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.

Ugh, I forgot to remove that note after doing the cleanups, I'll remove it
from the version of the patch my personal tree :)

>
>>
>> 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?

Maybe, this (no delay) is what the allwinner code was doing, and it
seems to work fine ...

>
>> +       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!

Regards,

Hans