
On 14/06/2022 02:46, Jim Liu wrote:
Hi,
Add Nuvoton BMC NPCM750 i2c driver
Signed-off-by: Jim Liu JJLIU0@nuvoton.com
changes for v3: - add i2c doc
I don't think this is needed. For a start, it's an old-style text binding. But more importantly I see that the kernel's I2C maintainer seemed to have merged the proper binding into his -next tree already.
https://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git/commit/?h=i2c/...
So there is no need to duplicate this binding document in the U-Boot tree, so you can just drop it here (again).
I haven't looked at the driver in detail, and I don't know the hardware nor can I test it, but at least I checked the devicetree aspect, and this is now in line with the accepted Linux kernel driver and DT changes, so it looks fine to me.
Cheers, Andre
Changes for v2: - use debug output in reset function - use clr/setbits_8
.../i2c/nuvoton,npcm7xx-i2c.txt | 28 + drivers/i2c/Kconfig | 5 + drivers/i2c/Makefile | 1 + drivers/i2c/npcm-i2c.c | 631 ++++++++++++++++++ 4 files changed, 665 insertions(+) create mode 100644 doc/device-tree-bindings/i2c/nuvoton,npcm7xx-i2c.txt create mode 100644 drivers/i2c/npcm-i2c.c
diff --git a/doc/device-tree-bindings/i2c/nuvoton,npcm7xx-i2c.txt b/doc/device-tree-bindings/i2c/nuvoton,npcm7xx-i2c.txt new file mode 100644 index 0000000000..d120490b32 --- /dev/null +++ b/doc/device-tree-bindings/i2c/nuvoton,npcm7xx-i2c.txt @@ -0,0 +1,28 @@ +* The NPCM750x includes sixteen I2C bus controllers.
+Required properties : +- compatible : Must be "nuvoton,npcm750-i2c" +- reg : Offset and length of the register set for the device +- clocks: Reference clock for the I2C bus +- A pinctrl state named "default" must be defined to set pins in mode of
- operation for I2C transfer
+- #address-cells = <1>; +- #size-cells = <0>;
+Optional properties : +- clock-frequency : Desired I2C bus clock frequency in Hz. If not specified,
- the default 100 kHz frequency will be used.
- possible values are 100000, 400000 and 1000000.
+Example :
- #include <dt-bindings/clock/nuvoton,npcm7xx-clock.h>
- #include <dt-bindings/interrupt-controller/arm-gic.h>
- i2c0: i2c@80000 {
reg = <0x80000 0x1000>;
compatible = "nuvoton,npcm750-i2c";
#address-cells = <1>;
#size-cells = <0>;
clocks = <&clk NPCM7XX_CLK_APB2>;
interrupts = <GIC_SPI 64 IRQ_TYPE_LEVEL_HIGH>;
status = "disabled";
- };
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..dfac6483de --- /dev/null +++ b/drivers/i2c/npcm-i2c.c @@ -0,0 +1,631 @@ +// 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(®->st));
- printf("SMBCST=0x%x\n", readb(®->cst));
- printf("SMBCTL1=0x%x\n", readb(®->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(®->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 */
- setbits_8(®->ctl1, SMBCTL1_START);
- start_time = get_timer(0);
- while (get_timer(start_time) < NPCM_I2C_TIMEOUT_MS) {
if (readb(®->st) & SMBST_BER)
return I2C_ERR_BER;
if (readb(®->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;
- setbits_8(®->ctl1, SMBCTL1_STOP);
- /* Clear NEGACK, STASTR and BER bits */
- writeb(SMBST_STASTR | SMBST_NEGACK | SMBST_BER, ®->st);
- bus->started = false;
- if (!wait)
return 0;
- start_time = get_timer(0);
- while (get_timer(start_time) < NPCM_I2C_TIMEOUT_MS) {
if ((readb(®->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;
- debug("%s: module %d\n", __func__, bus->num);
- /* disable & enable SMB moudle */
- clrbits_8(®->ctl2, SMBCTL2_ENABLE);
- setbits_8(®->ctl2, SMBCTL2_ENABLE);
- /* clear BB and status */
- writeb(SMBCST_BB, ®->cst);
- writeb(0xff, ®->st);
- /* select bank 1 */
- setbits_8(®->ctl3, SMBCTL3_BNK_SEL);
- /* Clear all fifo bits */
- writeb(SMBFIF_CTS_CLR_FIFO, ®->bank1.fif_cts);
- /* select bank 0 */
- clrbits_8(®->ctl3, SMBCTL3_BNK_SEL);
- /* clear EOB bit */
- writeb(SMBCST3_EO_BUSY, ®->bank0.cst3);
- /* single byte mode */
- clrbits_8(®->bank0.fif_ctl, SMBFIF_CTL_FIFO_EN);
- /* set POLL mode */
- writeb(0, ®->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(®->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, ®->cst);
udelay(20);
val = readb(®->ctl3);
if (val & SMBCTL3_SDA_LVL)
break;
if (iter-- == 0)
break;
- }
- if (val & SMBCTL3_SDA_LVL) {
writeb((u8)((addr << 1) & 0xff), ®->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)
setbits_8(®->ctl1, SMBCTL1_STASTRE);
- writeb(addr, ®->sda);
- if (stall) {
start_time = get_timer(0);
while (get_timer(start_time) < NPCM_I2C_TIMEOUT_MS) {
if (readb(®->st) & SMBST_STASTR)
break;
if (readb(®->st) & SMBST_BER) {
clrbits_8(®->ctl1, SMBCTL1_STASTRE);
return I2C_ERR_BER;
}
}
- }
- /* check ACK */
- val = readb(®->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 */
setbits_8(®->ctl1, SMBCTL1_ACK);
/* clear STASTRE if it is set */
if (readb(®->ctl1) & SMBCTL1_STASTRE) {
writeb(SMBST_STASTR, ®->st);
clrbits_8(®->ctl1, SMBCTL1_STASTRE);
}
npcm_i2c_check_sda(bus);
npcm_i2c_send_stop(bus, false);
*data = readb(®->sda);
/* this must be done to generate STOP condition */
writeb(SMBST_NEGACK, ®->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(®->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 */
setbits_8(®->ctl1, SMBCTL1_ACK);
}
if (i == (len - 1)) {
/* last byte, send STOP condition */
npcm_i2c_send_stop(bus, false);
*data = readb(®->sda);
writeb(SMBST_NEGACK, ®->st);
break;
}
*data = readb(®->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(®->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(®->ctl1) & SMBCTL1_STASTRE)
clrbits_8(®->ctl1, SMBCTL1_STASTRE);
- for (i = 0; i < len; i++) {
err = npcm_i2c_check_sda(bus);
if (err)
break;
writeb(*data, ®->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, ®->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)
clrbits_8(®->ctl1, SMBCTL1_STASTRE);
- 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, ®->st);
- for ( ; nmsgs > 0; nmsgs--, msg++) {
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(®->ctl2) & 0x1;
- val |= (sclfrq & 0x7F) << 1;
- writeb(val, ®->ctl2);
- /* clear 400K_MODE bit */
- val = readb(®->ctl3) & 0xc;
- val |= (sclfrq >> 7) & 0x3;
- writeb(val, ®->ctl3);
- writeb(hldt, ®->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 */
- setbits_8(®->ctl2, SMBCTL2_ENABLE);
- /* select register bank 0 */
- clrbits_8(®->ctl3, SMBCTL3_BNK_SEL);
- /* single byte mode */
- clrbits_8(®->bank0.fif_ctl, SMBFIF_CTL_FIFO_EN);
- /* set POLL mode */
- writeb(0, ®->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);
- return 0;
+}
+static const struct dm_i2c_ops nuvoton_i2c_ops = {
- .xfer = npcm_i2c_xfer,
- .set_bus_speed = npcm_i2c_set_bus_speed,
+};
+static const struct udevice_id nuvoton_i2c_of_match[] = {
- { .compatible = "nuvoton,npcm845-i2c", .data = NPCM8XX_I2CSEGCTL_INIT_VAL},
- { .compatible = "nuvoton,npcm750-i2c", .data = NPCM7XX_I2CSEGCTL_INIT_VAL},
- {}
+};
+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,
+};