diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-viai2c-zhaoxin.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-viai2c-zhaoxin.c | 298 |
1 files changed, 298 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-viai2c-zhaoxin.c b/drivers/i2c/busses/i2c-viai2c-zhaoxin.c new file mode 100644 index 000000000000..7e3ac2a3e1fd --- /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"); |