[PATCH v1] i2c: nuvoton: Add NPCM7xx i2c driver

Heiko Schocher hs at denx.de
Mon May 23 10:42:25 CEST 2022


Hello Jim,

On 23.05.22 10:16, Jim Liu wrote:
> Hi Heiko
> 
> Thanks for your reply.
> I will follow your suggestion to modify it for version 2.
> and some explain and question as below:
> 
> 1.  while function will do the i2c recovery feature .
>  the function will break when  toggle 27 times or SDA is high.
>> +     while (1) {
>> +             /* toggle SCL line */
>> +             writeb(SMBCST_TGSCL, &reg->cst);
>> +
>> +             udelay(20);
>> +             val = readb(&reg->ctl3);
>> +             if (val & SMBCTL3_SDA_LVL)
>> +                     break;
>> +             if (iter-- == 0)
>> +                     break;
>> +     }

Ah, yes, seems I was blind... sorry.

> 2. npcm845 is our new bmc and we are on-going to push it to linux.
> This link is our push status.
> https://patchwork.ozlabs.org/project/linux-i2c/patch/20220517101142.28421-10-warp5tw@gmail.com/

Ah, thanks!

> may i keep this npcm845 compatible or remove it?

If it gets accepted in linux, I am fine with it... ah I see:

https://lore.kernel.org/lkml/20220517101142.28421-2-warp5tw@gmail.com/

you add there the new compatible entry and have already a Reviewed-by
from Rob, so I think this is fine to accept it in u-boot too.

bye,
Heiko

> On Thu, May 19, 2022 at 12:48 PM Heiko Schocher <hs at denx.de> wrote:
>>
>> Hello Jim,
>>
>> On 17.05.22 10:25, Jim Liu wrote:
>>> Add Nuvoton BMC NPCM750 i2c driver
>>>
>>> Signed-off-by: Jim Liu <JJLIU0 at nuvoton.com>
>>> ---
>>>  drivers/i2c/Kconfig    |   5 +
>>>  drivers/i2c/Makefile   |   1 +
>>>  drivers/i2c/npcm-i2c.c | 632 +++++++++++++++++++++++++++++++++++++++++
>>>  3 files changed, 638 insertions(+)
>>>  create mode 100644 drivers/i2c/npcm-i2c.c
>>>
>>> diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
>>> index d25c5736ef..7e113b289e 100644
>>> --- a/drivers/i2c/Kconfig
>>> +++ b/drivers/i2c/Kconfig
>>> @@ -447,6 +447,11 @@ config SYS_I2C_NEXELL
>>>         have several I2C ports and all are provided, controlled by the
>>>         device tree.
>>>
>>> +config SYS_I2C_NPCM
>>> +     bool "Nuvoton NPCM I2C driver"
>>> +     help
>>> +       Support for Nuvoton I2C controller driver.
>>> +
>>>  config SYS_I2C_OCORES
>>>       bool "ocores I2C driver"
>>>       depends on DM_I2C
>>> diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
>>> index 9d41f379bb..7e046f809a 100644
>>> --- a/drivers/i2c/Makefile
>>> +++ b/drivers/i2c/Makefile
>>> @@ -33,6 +33,7 @@ obj-$(CONFIG_SYS_I2C_MV) += mv_i2c.o
>>>  obj-$(CONFIG_SYS_I2C_MVTWSI) += mvtwsi.o
>>>  obj-$(CONFIG_SYS_I2C_MXC) += mxc_i2c.o
>>>  obj-$(CONFIG_SYS_I2C_NEXELL) += nx_i2c.o
>>> +obj-$(CONFIG_SYS_I2C_NPCM) += npcm_i2c.o
>>>  obj-$(CONFIG_SYS_I2C_OCORES) += ocores_i2c.o
>>>  obj-$(CONFIG_SYS_I2C_OCTEON) += octeon_i2c.o
>>>  obj-$(CONFIG_SYS_I2C_OMAP24XX) += omap24xx_i2c.o
>>> diff --git a/drivers/i2c/npcm-i2c.c b/drivers/i2c/npcm-i2c.c
>>> new file mode 100644
>>> index 0000000000..5a066a164b
>>> --- /dev/null
>>> +++ b/drivers/i2c/npcm-i2c.c
>>> @@ -0,0 +1,632 @@
>>> +// SPDX-License-Identifier: GPL-2.0+
>>> +/*
>>> + * Copyright (c) 2021 Nuvoton Technology Corp.
>>> + */
>>> +
>>> +#include <clk.h>
>>> +#include <dm.h>
>>> +#include <i2c.h>
>>> +#include <asm/io.h>
>>> +#include <linux/iopoll.h>
>>> +#include <asm/arch/gcr.h>
>>> +
>>> +#define I2C_FREQ_100K                        100000
>>> +#define NPCM_I2C_TIMEOUT_MS          10
>>> +#define NPCM7XX_I2CSEGCTL_INIT_VAL   0x0333F000
>>> +#define NPCM8XX_I2CSEGCTL_INIT_VAL   0x9333F000
>>> +
>>> +/* SCLFRQ min/max field values  */
>>> +#define SCLFRQ_MIN           10
>>> +#define SCLFRQ_MAX           511
>>> +
>>> +/* SMBCTL1 */
>>> +#define SMBCTL1_START                BIT(0)
>>> +#define SMBCTL1_STOP         BIT(1)
>>> +#define SMBCTL1_INTEN                BIT(2)
>>> +#define SMBCTL1_ACK          BIT(4)
>>> +#define SMBCTL1_STASTRE              BIT(7)
>>> +
>>> +/* SMBCTL2 */
>>> +#define SMBCTL2_ENABLE               BIT(0)
>>> +
>>> +/* SMBCTL3 */
>>> +#define SMBCTL3_SCL_LVL              BIT(7)
>>> +#define SMBCTL3_SDA_LVL              BIT(6)
>>> +
>>> +/* SMBCST */
>>> +#define SMBCST_BB            BIT(1)
>>> +#define SMBCST_TGSCL         BIT(5)
>>> +
>>> +/* SMBST */
>>> +#define SMBST_XMIT           BIT(0)
>>> +#define SMBST_MASTER         BIT(1)
>>> +#define SMBST_STASTR         BIT(3)
>>> +#define SMBST_NEGACK         BIT(4)
>>> +#define SMBST_BER            BIT(5)
>>> +#define SMBST_SDAST          BIT(6)
>>> +
>>> +/* SMBCST3 in bank0 */
>>> +#define SMBCST3_EO_BUSY              BIT(7)
>>> +
>>> +/* SMBFIF_CTS in bank1 */
>>> +#define SMBFIF_CTS_CLR_FIFO  BIT(6)
>>> +
>>> +#define SMBFIF_CTL_FIFO_EN   BIT(4)
>>> +#define SMBCTL3_BNK_SEL              BIT(5)
>>> +
>>> +enum {
>>> +     I2C_ERR_NACK = 1,
>>> +     I2C_ERR_BER,
>>> +     I2C_ERR_TIMEOUT,
>>> +};
>>> +
>>> +struct smb_bank0_regs {
>>> +     u8 addr3;
>>> +     u8 addr7;
>>> +     u8 addr4;
>>> +     u8 addr8;
>>> +     u16 addr5;
>>> +     u16 addr6;
>>> +     u8 cst2;
>>> +     u8 cst3;
>>> +     u8 ctl4;
>>> +     u8 ctl5;
>>> +     u8 scllt;
>>> +     u8 fif_ctl;
>>> +     u8 sclht;
>>> +};
>>> +
>>> +struct smb_bank1_regs {
>>> +     u8 fif_cts;
>>> +     u8 fair_per;
>>> +     u16 txf_ctl;
>>> +     u32 t_out;
>>> +     u8 cst2;
>>> +     u8 cst3;
>>> +     u16 txf_sts;
>>> +     u16 rxf_sts;
>>> +     u8 rxf_ctl;
>>> +};
>>> +
>>> +struct npcm_i2c_regs {
>>> +     u16 sda;
>>> +     u16 st;
>>> +     u16 cst;
>>> +     u16 ctl1;
>>> +     u16 addr;
>>> +     u16 ctl2;
>>> +     u16 addr2;
>>> +     u16 ctl3;
>>> +     union {
>>> +             struct smb_bank0_regs bank0;
>>> +             struct smb_bank1_regs bank1;
>>> +     };
>>> +
>>> +};
>>> +
>>> +struct npcm_i2c_bus {
>>> +     struct npcm_i2c_regs *reg;
>>> +     int num;
>>> +     u32 apb_clk;
>>> +     u32 freq;
>>> +     bool started;
>>> +};
>>> +
>>> +static void npcm_dump_regs(struct npcm_i2c_bus *bus)
>>> +{
>>> +     struct npcm_i2c_regs *reg = bus->reg;
>>> +
>>> +     printf("\n");
>>> +     printf("SMBST=0x%x\n", readb(&reg->st));
>>> +     printf("SMBCST=0x%x\n", readb(&reg->cst));
>>> +     printf("SMBCTL1=0x%x\n", readb(&reg->ctl1));
>>> +     printf("\n");
>>> +}
>>> +
>>> +static int npcm_i2c_check_sda(struct npcm_i2c_bus *bus)
>>> +{
>>> +     struct npcm_i2c_regs *reg = bus->reg;
>>> +     ulong start_time;
>>> +     int err = I2C_ERR_TIMEOUT;
>>> +     u8 val;
>>> +
>>> +     start_time = get_timer(0);
>>> +     /* wait SDAST to be 1 */
>>> +     while (get_timer(start_time) < NPCM_I2C_TIMEOUT_MS) {
>>> +             val = readb(&reg->st);
>>> +             if (val & SMBST_NEGACK) {
>>> +                     err = I2C_ERR_NACK;
>>> +                     break;
>>> +             }
>>> +             if (val & SMBST_BER) {
>>> +                     err = I2C_ERR_BER;
>>> +                     break;
>>> +             }
>>> +             if (val & SMBST_SDAST) {
>>> +                     err = 0;
>>> +                     break;
>>> +             }
>>> +     }
>>> +
>>> +     if (err)
>>> +             printf("%s: err %d\n", __func__, err);
>>> +
>>> +     return err;
>>> +}
>>> +
>>> +static int npcm_i2c_send_start(struct npcm_i2c_bus *bus)
>>> +{
>>> +     struct npcm_i2c_regs *reg = bus->reg;
>>> +     ulong start_time;
>>> +     int err = I2C_ERR_TIMEOUT;
>>> +
>>> +     /* Generate START condition */
>>> +     writeb(readb(&reg->ctl1) | SMBCTL1_START, &reg->ctl1);
>>> +
>>> +     start_time = get_timer(0);
>>> +     while (get_timer(start_time) < NPCM_I2C_TIMEOUT_MS) {
>>> +             if (readb(&reg->st) & SMBST_BER)
>>> +                     return I2C_ERR_BER;
>>> +             if (readb(&reg->st) & SMBST_MASTER) {
>>> +                     err = 0;
>>> +                     break;
>>> +             }
>>> +     }
>>> +     bus->started = true;
>>> +
>>> +     return err;
>>> +}
>>> +
>>> +static int npcm_i2c_send_stop(struct npcm_i2c_bus *bus, bool wait)
>>> +{
>>> +     struct npcm_i2c_regs *reg = bus->reg;
>>> +     ulong start_time;
>>> +     int err = I2C_ERR_TIMEOUT;
>>> +
>>> +     writeb(readb(&reg->ctl1) | SMBCTL1_STOP, &reg->ctl1);
>>> +
>>> +     /* Clear NEGACK, STASTR and BER bits  */
>>> +     writeb(SMBST_STASTR | SMBST_NEGACK | SMBST_BER, &reg->st);
>>> +
>>> +     bus->started = false;
>>> +
>>> +     if (!wait)
>>> +             return 0;
>>> +
>>> +     start_time = get_timer(0);
>>> +     while (get_timer(start_time) < NPCM_I2C_TIMEOUT_MS) {
>>> +             if ((readb(&reg->ctl1) & SMBCTL1_STOP) == 0) {
>>> +                     err = 0;
>>> +                     break;
>>> +             }
>>> +     }
>>> +     if (err) {
>>> +             printf("%s: err %d\n", __func__, err);
>>> +             npcm_dump_regs(bus);
>>> +     }
>>> +
>>> +     return err;
>>> +}
>>> +
>>> +static void npcm_i2c_reset(struct npcm_i2c_bus *bus)
>>> +{
>>> +     struct npcm_i2c_regs *reg = bus->reg;
>>> +
>>> +     printf("%s: module %d\n", __func__, bus->num);
>>
>> May better only debug() ?
>>
>>> +     /* disable & enable SMB moudle */
>>> +     writeb(readb(&reg->ctl2) & ~SMBCTL2_ENABLE, &reg->ctl2);
>>> +     writeb(readb(&reg->ctl2) | SMBCTL2_ENABLE, &reg->ctl2);
>>
>> You may want to use here clr/setbits_8 and friends?
>>
>> Please use them in this driver, thanks!
>>
>>> +
>>> +     /* clear BB and status */
>>> +     writeb(SMBCST_BB, &reg->cst);
>>> +     writeb(0xff, &reg->st);
>>> +
>>> +     /* select bank 1 */
>>> +     writeb(readb(&reg->ctl3) | SMBCTL3_BNK_SEL, &reg->ctl3);
>>> +     /* Clear all fifo bits */
>>> +     writeb(SMBFIF_CTS_CLR_FIFO, &reg->bank1.fif_cts);
>>> +
>>> +     /* select bank 0 */
>>> +     writeb(readb(&reg->ctl3) & ~SMBCTL3_BNK_SEL, &reg->ctl3);
>>> +     /* clear EOB bit */
>>> +     writeb(SMBCST3_EO_BUSY, &reg->bank0.cst3);
>>> +     /* single byte mode */
>>> +     writeb(readb(&reg->bank0.fif_ctl) & ~SMBFIF_CTL_FIFO_EN, &reg->bank0.fif_ctl);
>>> +
>>> +     /* set POLL mode */
>>> +     writeb(0, &reg->ctl1);
>>> +}
>>> +
>>> +static void npcm_i2c_recovery(struct npcm_i2c_bus *bus, u32 addr)
>>> +{
>>> +     u8 val;
>>> +     int iter = 27;
>>> +     struct npcm_i2c_regs *reg = bus->reg;
>>> +     int err;
>>> +
>>> +     val = readb(&reg->ctl3);
>>> +     /* Skip recovery, bus not stucked */
>>> +     if ((val & SMBCTL3_SCL_LVL) && (val & SMBCTL3_SDA_LVL))
>>> +             return;
>>> +
>>> +     printf("Performing I2C bus %d recovery...\n", bus->num);
>>> +     /* SCL/SDA are not releaed, perform recovery */
>>> +     while (1) {
>>> +             /* toggle SCL line */
>>> +             writeb(SMBCST_TGSCL, &reg->cst);
>>> +
>>> +             udelay(20);
>>> +             val = readb(&reg->ctl3);
>>> +             if (val & SMBCTL3_SDA_LVL)
>>> +                     break;
>>> +             if (iter-- == 0)
>>> +                     break;
>>> +     }
>>
>> Hmm... endless while(1) ?
>>
>>> +
>>> +     if (val & SMBCTL3_SDA_LVL) {
>>> +             writeb((u8)((addr << 1) & 0xff), &reg->sda);
>>> +             err = npcm_i2c_send_start(bus);
>>> +             if (!err) {
>>> +                     udelay(20);
>>> +                     npcm_i2c_send_stop(bus, false);
>>> +                     udelay(200);
>>> +                     printf("I2C bus %d recovery completed\n",
>>> +                            bus->num);
>>> +             } else {
>>> +                     printf("%s: send START err %d\n", __func__, err);
>>> +             }
>>> +     } else {
>>> +             printf("Fail to recover I2C bus %d\n", bus->num);
>>> +     }
>>> +     npcm_i2c_reset(bus);
>>> +}
>>> +
>>> +static int npcm_i2c_send_address(struct npcm_i2c_bus *bus, u8 addr,
>>> +                              bool stall)
>>> +{
>>> +     struct npcm_i2c_regs *reg = bus->reg;
>>> +     ulong start_time;
>>> +     u8 val;
>>> +
>>> +     /* Stall After Start Enable */
>>> +     if (stall)
>>> +             writeb(readb(&reg->ctl1) | SMBCTL1_STASTRE, &reg->ctl1);
>>> +
>>> +     writeb(addr, &reg->sda);
>>> +     if (stall) {
>>> +             start_time = get_timer(0);
>>> +             while (get_timer(start_time) < NPCM_I2C_TIMEOUT_MS) {
>>> +                     if (readb(&reg->st) & SMBST_STASTR)
>>> +                             break;
>>> +
>>> +                     if (readb(&reg->st) & SMBST_BER) {
>>> +                             writeb(readb(&reg->ctl1) & ~SMBCTL1_STASTRE,
>>> +                                    &reg->ctl1);
>>> +                             return I2C_ERR_BER;
>>> +                     }
>>> +             }
>>> +     }
>>> +
>>> +     /* check ACK */
>>> +     val = readb(&reg->st);
>>> +     if (val & SMBST_NEGACK) {
>>> +             debug("NACK on addr 0x%x\n", addr >> 1);
>>> +             /* After a Stop condition, writing 1 to NEGACK clears it */
>>> +             return I2C_ERR_NACK;
>>> +     }
>>> +     if (val & SMBST_BER)
>>> +             return I2C_ERR_BER;
>>> +
>>> +     return 0;
>>> +}
>>> +
>>> +static int npcm_i2c_read_bytes(struct npcm_i2c_bus *bus, u8 *data, int len)
>>> +{
>>> +     struct npcm_i2c_regs *reg = bus->reg;
>>> +     u8 val;
>>> +     int i;
>>> +     int err = 0;
>>> +
>>> +     if (len == 1) {
>>> +             /* bus should be stalled before receiving last byte */
>>> +             writeb(readb(&reg->ctl1) | SMBCTL1_ACK, &reg->ctl1);
>>> +
>>> +             /* clear STASTRE if it is set */
>>> +             if (readb(&reg->ctl1) & SMBCTL1_STASTRE) {
>>> +                     writeb(SMBST_STASTR, &reg->st);
>>> +                     writeb(readb(&reg->ctl1) & ~SMBCTL1_STASTRE, &reg->ctl1);
>>> +             }
>>> +             npcm_i2c_check_sda(bus);
>>> +             npcm_i2c_send_stop(bus, false);
>>> +             *data = readb(&reg->sda);
>>> +             /* this must be done to generate STOP condition */
>>> +             writeb(SMBST_NEGACK, &reg->st);
>>> +     } else {
>>> +             for (i = 0; i < len; i++) {
>>> +                     /*
>>> +                      * When NEGACK bit is set to 1 after the transmission of a byte,
>>> +                      * SDAST is not set to 1.
>>> +                      */
>>> +                     if (i != (len - 1)) {
>>> +                             err = npcm_i2c_check_sda(bus);
>>> +                     } else {
>>> +                             err = readb_poll_timeout(&reg->ctl1, val,
>>> +                                                      !(val & SMBCTL1_ACK), 100000);
>>> +                             if (err) {
>>> +                                     printf("wait nack timeout\n");
>>> +                                     err = I2C_ERR_TIMEOUT;
>>> +                                     npcm_dump_regs(bus);
>>> +                             }
>>> +                     }
>>> +                     if (err && err != I2C_ERR_TIMEOUT)
>>> +                             break;
>>> +                     if (i == (len - 2)) {
>>> +                             /* set NACK before last byte */
>>> +                             writeb(readb(&reg->ctl1) | SMBCTL1_ACK, &reg->ctl1);
>>> +                     }
>>> +                     if (i == (len - 1)) {
>>> +                             /* last byte, send STOP condition */
>>> +                             npcm_i2c_send_stop(bus, false);
>>> +                             *data = readb(&reg->sda);
>>> +                             writeb(SMBST_NEGACK, &reg->st);
>>> +                             break;
>>> +                     }
>>> +                     *data = readb(&reg->sda);
>>> +                     data++;
>>> +             }
>>> +     }
>>> +
>>> +     return err;
>>> +}
>>> +
>>> +static int npcm_i2c_send_bytes(struct npcm_i2c_bus *bus, u8 *data, int len)
>>> +{
>>> +     struct npcm_i2c_regs *reg = bus->reg;
>>> +     u8 val;
>>> +     int i;
>>> +     int err = 0;
>>> +
>>> +     val = readb(&reg->st);
>>> +     if (val & SMBST_NEGACK)
>>> +             return I2C_ERR_NACK;
>>> +     else if (val & SMBST_BER)
>>> +             return I2C_ERR_BER;
>>> +
>>> +     /* clear STASTRE if it is set */
>>> +     if (readb(&reg->ctl1) & SMBCTL1_STASTRE)
>>> +             writeb(readb(&reg->ctl1) & ~SMBCTL1_STASTRE, &reg->ctl1);
>>> +
>>> +     for (i = 0; i < len; i++) {
>>> +             err = npcm_i2c_check_sda(bus);
>>> +             if (err)
>>> +                     break;
>>> +             writeb(*data, &reg->sda);
>>> +             data++;
>>> +     }
>>> +     npcm_i2c_check_sda(bus);
>>> +
>>> +     return err;
>>> +}
>>> +
>>> +static int npcm_i2c_read(struct npcm_i2c_bus *bus, u32 addr, u8 *data,
>>> +                      u32 len)
>>> +{
>>> +     struct npcm_i2c_regs *reg = bus->reg;
>>> +     int err;
>>> +     bool stall;
>>> +
>>> +     if (len <= 0)
>>> +             return -EINVAL;
>>> +
>>> +     /* send START condition */
>>> +     err = npcm_i2c_send_start(bus);
>>> +     if (err) {
>>> +             debug("%s: send START err %d\n", __func__, err);
>>> +             return err;
>>> +     }
>>> +
>>> +     stall = (len == 1) ? true : false;
>>> +     /* send address byte */
>>> +     err = npcm_i2c_send_address(bus, (u8)(addr << 1) | 0x1, stall);
>>> +
>>> +     if (!err && len)
>>> +             npcm_i2c_read_bytes(bus, data, len);
>>> +
>>> +     if (err == I2C_ERR_NACK) {
>>> +             /* clear NACK */
>>> +             writeb(SMBST_NEGACK, &reg->st);
>>> +     }
>>> +
>>> +     if (err)
>>> +             debug("%s: err %d\n", __func__, err);
>>> +
>>> +     return err;
>>> +}
>>> +
>>> +static int npcm_i2c_write(struct npcm_i2c_bus *bus, u32 addr, u8 *data,
>>> +                       u32 len)
>>> +{
>>> +     struct npcm_i2c_regs *reg = bus->reg;
>>> +     int err;
>>> +     bool stall;
>>> +
>>> +     /* send START condition */
>>> +     err = npcm_i2c_send_start(bus);
>>> +     if (err) {
>>> +             debug("%s: send START err %d\n", __func__, err);
>>> +             return err;
>>> +     }
>>> +
>>> +     stall = (len == 0) ? true : false;
>>> +     /* send address byte */
>>> +     err = npcm_i2c_send_address(bus, (u8)(addr << 1), stall);
>>> +
>>> +     if (!err && len)
>>> +             err = npcm_i2c_send_bytes(bus, data, len);
>>> +
>>> +     /* clear STASTRE if it is set */
>>> +     if (stall)
>>> +             writeb(readb(&reg->ctl1) & ~SMBCTL1_STASTRE, &reg->ctl1);
>>> +
>>> +     if (err)
>>> +             debug("%s: err %d\n", __func__, err);
>>> +
>>> +     return err;
>>> +}
>>> +
>>> +static int npcm_i2c_xfer(struct udevice *dev,
>>> +                      struct i2c_msg *msg, int nmsgs)
>>> +{
>>> +     struct npcm_i2c_bus *bus = dev_get_priv(dev);
>>> +     struct npcm_i2c_regs *reg = bus->reg;
>>> +     int ret = 0, err = 0;
>>> +
>>> +     if (nmsgs < 1 || nmsgs > 2) {
>>> +             printf("%s: commands not support\n", __func__);
>>> +             return -EREMOTEIO;
>>> +     }
>>> +     /* clear ST register */
>>> +     writeb(0xFF, &reg->st);
>>> +
>>> +     for ( ; nmsgs > 0; nmsgs--, msg++) {
>>
>> above you say no commands supported, so this for loop is useless ..or?
>>
>>> +             if (msg->flags & I2C_M_RD)
>>> +                     err = npcm_i2c_read(bus, msg->addr, msg->buf,
>>> +                                         msg->len);
>>> +             else
>>> +                     err = npcm_i2c_write(bus, msg->addr, msg->buf,
>>> +                                          msg->len);
>>> +             if (err) {
>>> +                     debug("i2c_xfer: error %d\n", err);
>>> +                     ret = -EREMOTEIO;
>>> +                     break;
>>> +             }
>>> +     }
>>> +
>>> +     if (bus->started)
>>> +             npcm_i2c_send_stop(bus, true);
>>> +
>>> +     if (err)
>>> +             npcm_i2c_recovery(bus, msg->addr);
>>> +
>>> +     return ret;
>>> +}
>>> +
>>> +static int npcm_i2c_init_clk(struct npcm_i2c_bus *bus, u32 bus_freq)
>>> +{
>>> +     struct npcm_i2c_regs *reg = bus->reg;
>>> +     u32 freq = bus->apb_clk;
>>> +     u32 sclfrq;
>>> +     u8 hldt, val;
>>> +
>>> +     if (bus_freq > I2C_FREQ_100K) {
>>> +             printf("Support standard mode only\n");
>>> +             return -EINVAL;
>>> +     }
>>> +
>>> +     /* SCLFRQ = T(SCL)/4/T(CLK) = FREQ(CLK)/4/FREQ(SCL) */
>>> +     sclfrq = freq / (bus_freq * 4);
>>> +     if (sclfrq < SCLFRQ_MIN || sclfrq > SCLFRQ_MAX)
>>> +             return -EINVAL;
>>> +
>>> +     if (freq >= 40000000)
>>> +             hldt = 17;
>>> +     else if (freq >= 12500000)
>>> +             hldt = 15;
>>> +     else
>>> +             hldt = 7;
>>> +
>>> +     val = readb(&reg->ctl2) & 0x1;
>>> +     val |= (sclfrq & 0x7F) << 1;
>>> +     writeb(val, &reg->ctl2);
>>> +
>>> +     /* clear 400K_MODE bit */
>>> +     val = readb(&reg->ctl3) & 0xc;
>>> +     val |= (sclfrq >> 7) & 0x3;
>>> +     writeb(val, &reg->ctl3);
>>> +
>>> +     writeb(hldt, &reg->bank0.ctl4);
>>> +
>>> +     return 0;
>>> +}
>>> +
>>> +static int npcm_i2c_set_bus_speed(struct udevice *dev,
>>> +                               unsigned int speed)
>>> +{
>>> +     struct npcm_i2c_bus *bus = dev_get_priv(dev);
>>> +
>>> +     return npcm_i2c_init_clk(bus, speed);
>>> +}
>>> +
>>> +static int npcm_i2c_probe(struct udevice *dev)
>>> +{
>>> +     struct npcm_i2c_bus *bus = dev_get_priv(dev);
>>> +     struct npcm_gcr *gcr = (struct npcm_gcr *)NPCM_GCR_BA;
>>> +     struct npcm_i2c_regs *reg;
>>> +     u32 i2csegctl_val = dev_get_driver_data(dev);
>>> +     struct clk clk;
>>> +     int ret;
>>> +
>>> +     ret = clk_get_by_index(dev, 0, &clk);
>>> +     if (ret) {
>>> +             printf("%s: ret %d\n", __func__, ret);
>>> +             return ret;
>>> +     }
>>> +     bus->apb_clk = clk_get_rate(&clk);
>>> +     if (bus->apb_clk <= 0) {
>>> +             printf("%s: fail to get rate\n", __func__);
>>> +             return -EINVAL;
>>> +     }
>>> +     clk_free(&clk);
>>> +
>>> +     bus->num = dev->seq_;
>>> +     bus->reg = dev_read_addr_ptr(dev);
>>> +     bus->freq = dev_read_u32_default(dev, "clock-frequency", 100000);
>>> +     bus->started = false;
>>> +     reg = bus->reg;
>>> +
>>> +     if (npcm_i2c_init_clk(bus, bus->freq)) {
>>> +             printf("%s: init_clk failed\n", __func__);
>>> +             return -EINVAL;
>>> +     }
>>> +
>>> +     /* set initial i2csegctl value */
>>> +     writel(i2csegctl_val, &gcr->i2csegctl);
>>> +
>>> +     /* enable SMB module */
>>> +     writeb(readb(&reg->ctl2) | SMBCTL2_ENABLE, &reg->ctl2);
>>> +
>>> +     /* select register bank 0 */
>>> +     writeb(readb(&reg->ctl3) & ~SMBCTL3_BNK_SEL, &reg->ctl3);
>>> +
>>> +     /* single byte mode */
>>> +     writeb(readb(&reg->bank0.fif_ctl) & ~SMBFIF_CTL_FIFO_EN, &reg->bank0.fif_ctl);
>>> +
>>> +     /* set POLL mode */
>>> +     writeb(0, &reg->ctl1);
>>> +
>>> +     printf("I2C bus %d ready. speed=%d, base=0x%x, apb=%u\n",
>>> +            bus->num, bus->freq, (u32)(uintptr_t)bus->reg, bus->apb_clk);
>>
>> Please use debug here.
>>
>>> +
>>> +     return 0;
>>> +}
>>> +
>>> +static const struct dm_i2c_ops nuvoton_i2c_ops = {
>>> +     .xfer               = npcm_i2c_xfer,
>>> +     .set_bus_speed  = npcm_i2c_set_bus_speed,
>>> +};
>>
>> As you have a deblock function, may you want to set
>> .deblock  here too?
>>
>>> +
>>> +static const struct udevice_id nuvoton_i2c_of_match[] = {
>>> +     { .compatible = "nuvoton,npcm845-i2c",  .data = NPCM8XX_I2CSEGCTL_INIT_VAL},
>>
>> I do not find this string in linux ... do you plan to push this
>> to linux?
>>
>>> +     { .compatible = "nuvoton,npcm750-i2c",  .data = NPCM7XX_I2CSEGCTL_INIT_VAL},
>>> +     {}
>>> +};
>>
>> and please document the bindings in u-boot:/doc/device-tree-bindings/i2c
>>
>>> +
>>> +U_BOOT_DRIVER(npcm_i2c_bus) = {
>>> +     .name = "npcm-i2c",
>>> +     .id = UCLASS_I2C,
>>> +     .of_match = nuvoton_i2c_of_match,
>>> +     .probe = npcm_i2c_probe,
>>> +     .priv_auto = sizeof(struct npcm_i2c_bus),
>>> +     .ops = &nuvoton_i2c_ops,
>>> +};
>>> +
>>>
>>
>> Thanks!
>>
>> bye,
>> Heiko
>> --
>> DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
>> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
>> Phone: +49-8142-66989-52   Fax: +49-8142-66989-80   Email: hs at denx.de

-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-52   Fax: +49-8142-66989-80   Email: hs at denx.de


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