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

Hello Jim,

On 17.05.22 10:25, Jim Liu wrote:

Add Nuvoton BMC NPCM750 i2c driver

Signed-off-by: Jim Liu JJLIU0@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