diff --git a/MAINTAINERS b/MAINTAINERS
index a3491d1aa7c372b19cb8fb9ab8525b4f296f1467..0927ea8c36f1353350aabac4aaf82a5fc0f14e29 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10258,6 +10258,14 @@ L: linux-i2c@vger.kernel.org
F: Documentation/i2c/busses/i2c-ismt.rst
F: drivers/i2c/busses/i2c-ismt.c
+I2C/SMBUS ZHAOXIN DRIVER
+M: Hans Hu <hanshu@zhaoxin.com>
+L: linux-i2c@vger.kernel.org
+S: Maintained
+W: https://www.zhaoxin.com
+F: drivers/i2c/busses/i2c-viai2c-common.c
+F: drivers/i2c/busses/i2c-viai2c-zhaoxin.c
+
I2C/SMBUS STUB DRIVER
M: Jean Delvare <jdelvare@suse.com>
L: linux-i2c@vger.kernel.org
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index a5aff29c559d0fce4c746842691f26eab111338a..fe6e8a1bb6072115991e808e0d5327b55933d23f 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -344,6 +344,16 @@ config I2C_VIAPRO
if ACPI
+config I2C_ZHAOXIN
+ tristate "Zhaoxin I2C Interface"
+ depends on PCI || COMPILE_TEST
+ help
+ If you say yes to this option, support will be included for the
+ ZHAOXIN I2C interface
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-zhaoxin.
+
comment "ACPI drivers"
config I2C_SCMI
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 63c7bbad8134fcf15e5177bad1029cdb84424005..3d65934f5eb4863f59ef2979850c5554395cc955 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -29,6 +29,8 @@ obj-$(CONFIG_I2C_SIS630) += i2c-sis630.o
obj-$(CONFIG_I2C_SIS96X) += i2c-sis96x.o
obj-$(CONFIG_I2C_VIA) += i2c-via.o
obj-$(CONFIG_I2C_VIAPRO) += i2c-viapro.o
+i2c-zhaoxin-objs := i2c-viai2c-zhaoxin.o i2c-viai2c-common.o
+obj-$(CONFIG_I2C_ZHAOXIN) += i2c-zhaoxin.o
# Mac SMBus host controller drivers
obj-$(CONFIG_I2C_HYDRA) += i2c-hydra.o
diff --git a/drivers/i2c/busses/i2c-viai2c-common.c b/drivers/i2c/busses/i2c-viai2c-common.c
index 22a2e31e9c14b42c1c15d1de20e07a3343a2612b..1844d13f1f79866fbe81d7960d7c13c816868966 100644
--- a/drivers/i2c/busses/i2c-viai2c-common.c
+++ b/drivers/i2c/busses/i2c-viai2c-common.c
@@ -60,7 +60,7 @@ static int viai2c_write(struct viai2c *i2c, struct i2c_msg *pmsg, int last)
return i2c->ret;
}
-static int viai2c_read(struct viai2c *i2c, struct i2c_msg *pmsg)
+static int viai2c_read(struct viai2c *i2c, struct i2c_msg *pmsg, bool first)
{
u16 val, tcr_val = i2c->tcr;
@@ -81,7 +81,8 @@ static int viai2c_read(struct viai2c *i2c, struct i2c_msg *pmsg)
writew(tcr_val, i2c->base + VIAI2C_REG_TCR);
- if (i2c->platform == VIAI2C_PLAT_WMT && (pmsg->flags & I2C_M_NOSTART)) {
+ if ((i2c->platform == VIAI2C_PLAT_WMT && (pmsg->flags & I2C_M_NOSTART)) ||
+ (i2c->platform == VIAI2C_PLAT_ZHAOXIN && !first)) {
val = readw(i2c->base + VIAI2C_REG_CR);
val |= VIAI2C_CR_CPU_RDY;
writew(val, i2c->base + VIAI2C_REG_CR);
@@ -100,6 +101,7 @@ int viai2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
int ret = 0;
struct viai2c *i2c = i2c_get_adapdata(adap);
+ i2c->mode = VIAI2C_BYTE_MODE;
for (i = 0; ret >= 0 && i < num; i++) {
pmsg = &msgs[i];
if (i2c->platform == VIAI2C_PLAT_WMT && !(pmsg->flags & I2C_M_NOSTART)) {
@@ -112,7 +114,7 @@ int viai2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
i2c->xfered_len = 0;
if (pmsg->flags & I2C_M_RD)
- ret = viai2c_read(i2c, pmsg);
+ ret = viai2c_read(i2c, pmsg, i == 0);
else
ret = viai2c_write(i2c, pmsg, (i + 1) == num);
}
@@ -157,6 +159,8 @@ static int viai2c_irq_xfer(struct viai2c *i2c)
if ((i2c->xfered_len + 1) == msg->len) {
if (i2c->platform == VIAI2C_PLAT_WMT && !i2c->last)
writew(VIAI2C_CR_ENABLE, base + VIAI2C_REG_CR);
+ else if (i2c->platform == VIAI2C_PLAT_ZHAOXIN && i2c->last)
+ writeb(VIAI2C_CR_TX_END, base + VIAI2C_REG_CR);
} else {
writew(msg->buf[i2c->xfered_len + 1] & 0xFF, base + VIAI2C_REG_CDR);
writew(VIAI2C_CR_CPU_RDY | VIAI2C_CR_ENABLE, base + VIAI2C_REG_CR);
@@ -168,6 +172,11 @@ static int viai2c_irq_xfer(struct viai2c *i2c)
return i2c->xfered_len == msg->len;
}
+int __weak viai2c_fifo_irq_xfer(struct viai2c *i2c, bool irq)
+{
+ return 0;
+}
+
static irqreturn_t viai2c_isr(int irq, void *data)
{
struct viai2c *i2c = data;
@@ -175,6 +184,9 @@ static irqreturn_t viai2c_isr(int irq, void *data)
/* save the status and write-clear it */
status = readw(i2c->base + VIAI2C_REG_ISR);
+ if (!status && i2c->platform == VIAI2C_PLAT_ZHAOXIN)
+ return IRQ_NONE;
+
writew(status, i2c->base + VIAI2C_REG_ISR);
i2c->ret = 0;
@@ -184,8 +196,12 @@ static irqreturn_t viai2c_isr(int irq, void *data)
if (i2c->platform == VIAI2C_PLAT_WMT && (status & VIAI2C_ISR_SCL_TIMEOUT))
i2c->ret = -ETIMEDOUT;
- if (!i2c->ret)
- i2c->ret = viai2c_irq_xfer(i2c);
+ if (!i2c->ret) {
+ if (i2c->mode == VIAI2C_BYTE_MODE)
+ i2c->ret = viai2c_irq_xfer(i2c);
+ else
+ i2c->ret = viai2c_fifo_irq_xfer(i2c, true);
+ }
/* All the data has been successfully transferred or error occurred */
if (i2c->ret)
@@ -214,6 +230,11 @@ int viai2c_init(struct platform_device *pdev, struct viai2c **pi2c, int plat)
i2c->irq = irq_of_parse_and_map(np, 0);
if (!i2c->irq)
return -EINVAL;
+ } else if (plat == VIAI2C_PLAT_ZHAOXIN) {
+ irq_flags = IRQF_SHARED;
+ i2c->irq = platform_get_irq(pdev, 0);
+ if (i2c->irq < 0)
+ return i2c->irq;
} else {
return dev_err_probe(&pdev->dev, -EINVAL, "wrong platform type\n");
}
diff --git a/drivers/i2c/busses/i2c-viai2c-common.h b/drivers/i2c/busses/i2c-viai2c-common.h
index cfe5ab2bd7792d37e4fd2951dd2c9f566b33bad7..81e827c544347d7b27003829388fec56f014c3fa 100644
--- a/drivers/i2c/busses/i2c-viai2c-common.h
+++ b/drivers/i2c/busses/i2c-viai2c-common.h
@@ -52,6 +52,12 @@
enum {
VIAI2C_PLAT_WMT,
+ VIAI2C_PLAT_ZHAOXIN
+};
+
+enum {
+ VIAI2C_BYTE_MODE,
+ VIAI2C_FIFO_MODE
};
struct viai2c {
@@ -66,11 +72,14 @@ struct viai2c {
struct i2c_msg *msg;
int ret;
bool last;
+ unsigned int mode;
unsigned int platform;
+ void *pltfm_priv;
};
int viai2c_wait_bus_not_busy(struct viai2c *i2c);
int viai2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num);
int viai2c_init(struct platform_device *pdev, struct viai2c **pi2c, int plat);
+int viai2c_fifo_irq_xfer(struct viai2c *i2c, bool irq);
#endif
diff --git a/drivers/i2c/busses/i2c-viai2c-zhaoxin.c b/drivers/i2c/busses/i2c-viai2c-zhaoxin.c
new file mode 100644
index 0000000000000000000000000000000000000000..7e3ac2a3e1fd73928b2beb1097406639faf7a01e
--- /dev/null
+++ b/drivers/i2c/busses/i2c-viai2c-zhaoxin.c
@@ -0,0 +1,298 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright(c) 2024 Shanghai Zhaoxin Semiconductor Corporation.
+ * All rights reserved.
+ */
+
+#include <linux/acpi.h>
+#include "i2c-viai2c-common.h"
+
+/*
+ * registers
+ */
+/* Zhaoxin specific register bit fields */
+/* REG_CR Bit fields */
+#define ZXI2C_CR_MST_RST BIT(7)
+#define ZXI2C_CR_FIFO_MODE BIT(14)
+/* REG_ISR/IMR Bit fields */
+#define ZXI2C_IRQ_FIFONACK BIT(4)
+#define ZXI2C_IRQ_FIFOEND BIT(3)
+#define ZXI2C_IRQ_MASK (VIAI2C_ISR_MASK_ALL \
+ | ZXI2C_IRQ_FIFOEND \
+ | ZXI2C_IRQ_FIFONACK)
+/* Zhaoxin specific registers */
+#define ZXI2C_REG_CLK 0x10
+#define ZXI2C_CLK_50M BIT(0)
+#define ZXI2C_REG_REV 0x11
+#define ZXI2C_REG_HCR 0x12
+#define ZXI2C_HCR_RST_FIFO GENMASK(1, 0)
+#define ZXI2C_REG_HTDR 0x13
+#define ZXI2C_REG_HRDR 0x14
+#define ZXI2C_REG_HTLR 0x15
+#define ZXI2C_REG_HRLR 0x16
+#define ZXI2C_REG_HWCNTR 0x18
+#define ZXI2C_REG_HRCNTR 0x19
+
+/* parameters Constants */
+#define ZXI2C_GOLD_FSTP_100K 0xF3
+#define ZXI2C_GOLD_FSTP_400K 0x38
+#define ZXI2C_GOLD_FSTP_1M 0x13
+#define ZXI2C_GOLD_FSTP_3400K 0x37
+#define ZXI2C_HS_MASTER_CODE (0x08 << 8)
+
+#define ZXI2C_FIFO_SIZE 32
+
+struct viai2c_zhaoxin {
+ u8 hrv;
+ u16 tr;
+ u16 mcr;
+ u16 xfer_len;
+};
+
+/* 'irq == true' means in interrupt context */
+int viai2c_fifo_irq_xfer(struct viai2c *i2c, bool irq)
+{
+ u16 i;
+ u8 tmp;
+ struct i2c_msg *msg = i2c->msg;
+ void __iomem *base = i2c->base;
+ bool read = !!(msg->flags & I2C_M_RD);
+ struct viai2c_zhaoxin *priv = i2c->pltfm_priv;
+
+ if (irq) {
+ /* get the received data */
+ if (read)
+ for (i = 0; i < priv->xfer_len; i++)
+ msg->buf[i2c->xfered_len + i] = ioread8(base + ZXI2C_REG_HRDR);
+
+ i2c->xfered_len += priv->xfer_len;
+ if (i2c->xfered_len == msg->len)
+ return 1;
+ }
+
+ /* reset fifo buffer */
+ tmp = ioread8(base + ZXI2C_REG_HCR);
+ iowrite8(tmp | ZXI2C_HCR_RST_FIFO, base + ZXI2C_REG_HCR);
+
+ /* set xfer len */
+ priv->xfer_len = min_t(u16, msg->len - i2c->xfered_len, ZXI2C_FIFO_SIZE);
+ if (read) {
+ iowrite8(priv->xfer_len - 1, base + ZXI2C_REG_HRLR);
+ } else {
+ iowrite8(priv->xfer_len - 1, base + ZXI2C_REG_HTLR);
+ /* set write data */
+ for (i = 0; i < priv->xfer_len; i++)
+ iowrite8(msg->buf[i2c->xfered_len + i], base + ZXI2C_REG_HTDR);
+ }
+
+ /* prepare to stop transmission */
+ if (priv->hrv && msg->len == (i2c->xfered_len + priv->xfer_len)) {
+ tmp = ioread8(base + VIAI2C_REG_CR);
+ tmp |= read ? VIAI2C_CR_RX_END : VIAI2C_CR_TX_END;
+ iowrite8(tmp, base + VIAI2C_REG_CR);
+ }
+
+ if (irq) {
+ /* continue transmission */
+ tmp = ioread8(base + VIAI2C_REG_CR);
+ iowrite8(tmp |= VIAI2C_CR_CPU_RDY, base + VIAI2C_REG_CR);
+ } else {
+ u16 tcr_val = i2c->tcr;
+
+ /* start transmission */
+ tcr_val |= read ? VIAI2C_TCR_READ : 0;
+ writew(tcr_val | msg->addr, base + VIAI2C_REG_TCR);
+ }
+
+ return 0;
+}
+
+static int zxi2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ u8 tmp;
+ int ret;
+ struct viai2c *i2c = (struct viai2c *)i2c_get_adapdata(adap);
+ struct viai2c_zhaoxin *priv = i2c->pltfm_priv;
+ void __iomem *base = i2c->base;
+
+ ret = viai2c_wait_bus_not_busy(i2c);
+ if (ret)
+ return ret;
+
+ tmp = ioread8(base + VIAI2C_REG_CR);
+ tmp &= ~(VIAI2C_CR_RX_END | VIAI2C_CR_TX_END);
+
+ if (num == 1 && msgs->len >= 2 && (priv->hrv || msgs->len <= ZXI2C_FIFO_SIZE)) {
+ /* enable fifo mode */
+ iowrite16(ZXI2C_CR_FIFO_MODE | tmp, base + VIAI2C_REG_CR);
+ /* clear irq status */
+ iowrite8(ZXI2C_IRQ_MASK, base + VIAI2C_REG_ISR);
+ /* enable fifo irq */
+ iowrite8(VIAI2C_ISR_NACK_ADDR | ZXI2C_IRQ_FIFOEND, base + VIAI2C_REG_IMR);
+
+ i2c->msg = msgs;
+ i2c->mode = VIAI2C_FIFO_MODE;
+ priv->xfer_len = 0;
+ i2c->xfered_len = 0;
+
+ viai2c_fifo_irq_xfer(i2c, 0);
+
+ if (!wait_for_completion_timeout(&i2c->complete, VIAI2C_TIMEOUT))
+ return -ETIMEDOUT;
+
+ ret = i2c->ret;
+ } else {
+ /* enable byte mode */
+ iowrite16(tmp, base + VIAI2C_REG_CR);
+ /* clear irq status */
+ iowrite8(ZXI2C_IRQ_MASK, base + VIAI2C_REG_ISR);
+ /* enable byte irq */
+ iowrite8(VIAI2C_ISR_NACK_ADDR | VIAI2C_IMR_BYTE, base + VIAI2C_REG_IMR);
+
+ ret = viai2c_xfer(adap, msgs, num);
+ if (ret == -ETIMEDOUT)
+ iowrite16(tmp | VIAI2C_CR_END_MASK, base + VIAI2C_REG_CR);
+ }
+ /* dis interrupt */
+ iowrite8(0, base + VIAI2C_REG_IMR);
+
+ return ret;
+}
+
+static u32 zxi2c_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm zxi2c_algorithm = {
+ .master_xfer = zxi2c_master_xfer,
+ .functionality = zxi2c_func,
+};
+
+static const struct i2c_adapter_quirks zxi2c_quirks = {
+ .flags = I2C_AQ_NO_ZERO_LEN | I2C_AQ_COMB_WRITE_THEN_READ,
+};
+
+static const u32 zxi2c_speed_params_table[][3] = {
+ /* speed, ZXI2C_TCR, ZXI2C_FSTP */
+ { I2C_MAX_STANDARD_MODE_FREQ, 0, ZXI2C_GOLD_FSTP_100K },
+ { I2C_MAX_FAST_MODE_FREQ, VIAI2C_TCR_FAST, ZXI2C_GOLD_FSTP_400K },
+ { I2C_MAX_FAST_MODE_PLUS_FREQ, VIAI2C_TCR_FAST, ZXI2C_GOLD_FSTP_1M },
+ { I2C_MAX_HIGH_SPEED_MODE_FREQ, VIAI2C_TCR_HS_MODE | VIAI2C_TCR_FAST,
+ ZXI2C_GOLD_FSTP_3400K },
+};
+
+static void zxi2c_set_bus_speed(struct viai2c *i2c)
+{
+ struct viai2c_zhaoxin *priv = i2c->pltfm_priv;
+
+ iowrite16(priv->tr, i2c->base + VIAI2C_REG_TR);
+ iowrite8(ZXI2C_CLK_50M, i2c->base + ZXI2C_REG_CLK);
+ iowrite16(priv->mcr, i2c->base + VIAI2C_REG_MCR);
+}
+
+static void zxi2c_get_bus_speed(struct viai2c *i2c)
+{
+ u8 i, count;
+ u8 fstp;
+ const u32 *params;
+ struct viai2c_zhaoxin *priv = i2c->pltfm_priv;
+ u32 acpi_speed = i2c_acpi_find_bus_speed(i2c->dev);
+
+ count = ARRAY_SIZE(zxi2c_speed_params_table);
+ for (i = 0; i < count; i++)
+ if (acpi_speed == zxi2c_speed_params_table[i][0])
+ break;
+ /* if not found, use 400k as default */
+ i = i < count ? i : 1;
+
+ params = zxi2c_speed_params_table[i];
+ fstp = ioread8(i2c->base + VIAI2C_REG_TR);
+ if (abs(fstp - params[2]) > 0x10) {
+ /*
+ * if BIOS setting value far from golden value,
+ * use golden value and warn user
+ */
+ dev_warn(i2c->dev, "FW FSTP[%x] might cause wrong timings, dropped\n", fstp);
+ priv->tr = params[2] | 0xff00;
+ } else {
+ priv->tr = fstp | 0xff00;
+ }
+
+ i2c->tcr = params[1];
+ priv->mcr = ioread16(i2c->base + VIAI2C_REG_MCR);
+ /* for Hs-mode, use 0x80 as master code */
+ if (params[0] == I2C_MAX_HIGH_SPEED_MODE_FREQ)
+ priv->mcr |= ZXI2C_HS_MASTER_CODE;
+
+ dev_info(i2c->dev, "speed mode is %s\n", i2c_freq_mode_string(params[0]));
+}
+
+static int zxi2c_probe(struct platform_device *pdev)
+{
+ int error;
+ struct viai2c *i2c;
+ struct i2c_adapter *adap;
+ struct viai2c_zhaoxin *priv;
+
+ error = viai2c_init(pdev, &i2c, VIAI2C_PLAT_ZHAOXIN);
+ if (error)
+ return error;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+ i2c->pltfm_priv = priv;
+
+ zxi2c_get_bus_speed(i2c);
+ zxi2c_set_bus_speed(i2c);
+
+ priv->hrv = ioread8(i2c->base + ZXI2C_REG_REV);
+
+ adap = &i2c->adapter;
+ adap->owner = THIS_MODULE;
+ adap->algo = &zxi2c_algorithm;
+ adap->quirks = &zxi2c_quirks;
+ adap->dev.parent = &pdev->dev;
+ ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
+ snprintf(adap->name, sizeof(adap->name), "zhaoxin-%s-%s",
+ dev_name(pdev->dev.parent), dev_name(i2c->dev));
+ i2c_set_adapdata(adap, i2c);
+
+ return devm_i2c_add_adapter(&pdev->dev, adap);
+}
+
+static int __maybe_unused zxi2c_resume(struct device *dev)
+{
+ struct viai2c *i2c = dev_get_drvdata(dev);
+
+ iowrite8(ZXI2C_CR_MST_RST, i2c->base + VIAI2C_REG_CR);
+ zxi2c_set_bus_speed(i2c);
+
+ return 0;
+}
+
+static const struct dev_pm_ops zxi2c_pm = {
+ SET_SYSTEM_SLEEP_PM_OPS(NULL, zxi2c_resume)
+};
+
+static const struct acpi_device_id zxi2c_acpi_match[] = {
+ {"IIC1D17", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(acpi, zxi2c_acpi_match);
+
+static struct platform_driver zxi2c_driver = {
+ .probe = zxi2c_probe,
+ .driver = {
+ .name = "i2c_zhaoxin",
+ .acpi_match_table = zxi2c_acpi_match,
+ .pm = &zxi2c_pm,
+ },
+};
+
+module_platform_driver(zxi2c_driver);
+
+MODULE_AUTHOR("HansHu@zhaoxin.com");
+MODULE_DESCRIPTION("Shanghai Zhaoxin IIC driver");
+MODULE_LICENSE("GPL");