diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index a7bfddf08fa7ba..c04b9486bd3302 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -1457,4 +1457,11 @@ config I2C_VIRTIO This driver can also be built as a module. If so, the module will be called i2c-virtio. +config I2C_GXP + tristate "GXP I2C Interface" + depends on ARCH_HPE_GXP || COMPILE_TEST + help + This enables support for GXP I2C interface. The I2C engines can be + either I2C master or I2C slaves. + endmenu diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index e73cdb1d2b5a85..dcc96eab6d68b7 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -127,6 +127,7 @@ obj-$(CONFIG_I2C_THUNDERX) += i2c-thunderx.o obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o obj-$(CONFIG_I2C_XLP9XX) += i2c-xlp9xx.o obj-$(CONFIG_I2C_RCAR) += i2c-rcar.o +obj-$(CONFIG_I2C_GXP) += i2c-gxp.o # External I2C/SMBus adapter drivers obj-$(CONFIG_I2C_DIOLAN_U2C) += i2c-diolan-u2c.o diff --git a/drivers/i2c/busses/i2c-gxp.c b/drivers/i2c/busses/i2c-gxp.c new file mode 100644 index 00000000000000..fb5cae6b5f009a --- /dev/null +++ b/drivers/i2c/busses/i2c-gxp.c @@ -0,0 +1,602 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (C) 2022 Hewlett-Packard Enterprise Development Company, L.P. */ + +#include +#include +#include +#include +#include +#include +#include + +#define GXP_MAX_I2C_ENGINE 10 +static const char * const gxp_i2c_name[] = { + "gxp-i2c0", "gxp-i2c1", "gxp-i2c2", "gxp-i2c3", + "gxp-i2c4", "gxp-i2c5", "gxp-i2c6", "gxp-i2c7", + "gxp-i2c8", "gxp-i2c9" }; + +/* GXP I2C Global interrupt status/enable register*/ +#define GXP_I2CINTSTAT 0x00 +#define GXP_I2CINTEN 0x04 + +/* GXP I2C registers */ +#define GXP_I2CSTAT 0x00 +#define MASK_STOP_EVENT 0x20 +#define MASK_ACK 0x08 +#define MASK_RW 0x04 +#define GXP_I2CEVTERR 0x01 +#define MASK_SLAVE_CMD_EVENT 0x01 +#define MASK_SLAVE_DATA_EVENT 0x02 +#define MASK_MASTER_EVENT 0x10 +#define GXP_I2CSNPDAT 0x02 +#define GXP_I2CMCMD 0x04 +#define GXP_I2CSCMD 0x06 +#define GXP_I2CSNPAA 0x09 +#define GXP_I2CADVFEAT 0x0A +#define GXP_I2COWNADR 0x0B +#define GXP_I2CFREQDIV 0x0C +#define GXP_I2CFLTFAIR 0x0D +#define GXP_I2CTMOEDG 0x0E +#define GXP_I2CCYCTIM 0x0F + +static bool i2c_global_init_done; + +enum { + GXP_I2C_IDLE = 0, + GXP_I2C_ADDR_PHASE, + GXP_I2C_RDATA_PHASE, + GXP_I2C_WDATA_PHASE, + GXP_I2C_ADDR_NACK, + GXP_I2C_DATA_NACK, + GXP_I2C_ERROR, + GXP_I2C_COMP +}; + +struct gxp_i2c_drvdata { + struct device *dev; + void __iomem *base; + struct i2c_timings t; + int engine; + int irq; + struct completion completion; + struct i2c_adapter adapter; + struct i2c_msg *curr_msg; + int msgs_remaining; + int msgs_num; + u8 *buf; + size_t buf_remaining; + unsigned char state; + struct i2c_client *slave; + unsigned char stopped; +}; + +static struct regmap *i2cg_map; + +static void gxp_i2c_start(struct gxp_i2c_drvdata *drvdata) +{ + u16 value; + + drvdata->buf = drvdata->curr_msg->buf; + drvdata->buf_remaining = drvdata->curr_msg->len; + + /* Note: Address in struct i2c_msg is 7 bits */ + value = drvdata->curr_msg->addr << 9; + + if (drvdata->curr_msg->flags & I2C_M_RD) { + /* Read */ + value |= 0x05; + } else { + /* Write */ + value |= 0x01; + } + + drvdata->state = GXP_I2C_ADDR_PHASE; + writew(value, drvdata->base + GXP_I2CMCMD); +} + +static int gxp_i2c_master_xfer(struct i2c_adapter *adapter, + struct i2c_msg *msgs, int num) +{ + int ret; + struct gxp_i2c_drvdata *drvdata = i2c_get_adapdata(adapter); + unsigned long time_left; + + drvdata->msgs_remaining = num; + drvdata->curr_msg = msgs; + drvdata->msgs_num = num; + reinit_completion(&drvdata->completion); + + gxp_i2c_start(drvdata); + + time_left = wait_for_completion_timeout(&drvdata->completion, + adapter->timeout); + ret = num - drvdata->msgs_remaining; + if (time_left == 0) { + switch (drvdata->state) { + case GXP_I2C_WDATA_PHASE: + dev_err(drvdata->dev, + "gxp_i2c_start:write Data phase timeout at msg[%d]\n", + ret); + break; + case GXP_I2C_RDATA_PHASE: + dev_err(drvdata->dev, + "gxp_i2c_start:read Data phase timeout at msg[%d]\n", + ret); + break; + case GXP_I2C_ADDR_PHASE: + dev_err(drvdata->dev, + "gxp_i2c_start:Addr phase timeout\n"); + break; + default: + dev_err(drvdata->dev, + "gxp_i2c_start:i2c transfer timeout state=%d\n", + drvdata->state); + break; + } + return -ETIMEDOUT; + } + + if (drvdata->state == GXP_I2C_ADDR_NACK) { + dev_err(drvdata->dev, + "gxp_i2c_start:No ACK for address phase\n"); + return -EIO; + } else if (drvdata->state == GXP_I2C_DATA_NACK) { + dev_err(drvdata->dev, "gxp_i2c_start:No ACK for data phase\n"); + return -EIO; + } + + return ret; +} + +static u32 gxp_i2c_func(struct i2c_adapter *adap) +{ + if (IS_ENABLED(CONFIG_I2C_SLAVE)) + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SLAVE; + + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +#if IS_ENABLED(CONFIG_I2C_SLAVE) +static int gxp_i2c_reg_slave(struct i2c_client *slave) +{ + struct gxp_i2c_drvdata *drvdata = i2c_get_adapdata(slave->adapter); + + if (drvdata->slave) + return -EBUSY; + + if (slave->flags & I2C_CLIENT_TEN) + return -EAFNOSUPPORT; + + drvdata->slave = slave; + + writeb(slave->addr << 1, drvdata->base + GXP_I2COWNADR); + writeb(0x69, drvdata->base + GXP_I2CSCMD); + + return 0; +} + +static int gxp_i2c_unreg_slave(struct i2c_client *slave) +{ + struct gxp_i2c_drvdata *drvdata = i2c_get_adapdata(slave->adapter); + + WARN_ON(!drvdata->slave); + + writeb(0x00, drvdata->base + GXP_I2COWNADR); + writeb(0xF0, drvdata->base + GXP_I2CSCMD); + + drvdata->slave = NULL; + + return 0; +} +#endif + +static const struct i2c_algorithm gxp_i2c_algo = { + .master_xfer = gxp_i2c_master_xfer, + .functionality = gxp_i2c_func, +#if IS_ENABLED(CONFIG_I2C_SLAVE) + .reg_slave = gxp_i2c_reg_slave, + .unreg_slave = gxp_i2c_unreg_slave, +#endif +}; + +static void gxp_i2c_stop(struct gxp_i2c_drvdata *drvdata) +{ + /* Clear event and send stop */ + writeb(0x82, drvdata->base + GXP_I2CMCMD); + + complete(&drvdata->completion); +} + +static void gxp_i2c_restart(struct gxp_i2c_drvdata *drvdata) +{ + u16 value; + + drvdata->buf = drvdata->curr_msg->buf; + drvdata->buf_remaining = drvdata->curr_msg->len; + + value = drvdata->curr_msg->addr << 9; + + if (drvdata->curr_msg->flags & I2C_M_RD) { + /* Read and clear master event */ + value |= 0x85; + } else { + /* Write and clear master event */ + value |= 0x81; + } + + drvdata->state = GXP_I2C_ADDR_PHASE; + + writew(value, drvdata->base + GXP_I2CMCMD); +} + +static void gxp_i2c_chk_addr_ack(struct gxp_i2c_drvdata *drvdata) +{ + u16 value; + + value = readb(drvdata->base + GXP_I2CSTAT); + if (!(value & MASK_ACK)) { + /* Got no ack, stop */ + drvdata->state = GXP_I2C_ADDR_NACK; + gxp_i2c_stop(drvdata); + return; + } + + if (drvdata->curr_msg->flags & I2C_M_RD) { + /* Start to read data from slave */ + if (drvdata->buf_remaining == 0) { + /* No more data to read, stop */ + drvdata->msgs_remaining--; + drvdata->state = GXP_I2C_COMP; + gxp_i2c_stop(drvdata); + return; + } + drvdata->state = GXP_I2C_RDATA_PHASE; + + if (drvdata->buf_remaining == 1) { + /* The last data, do not ack */ + writeb(0x84, drvdata->base + GXP_I2CMCMD); + } else { + /* Read data and ack it */ + writeb(0x8C, drvdata->base + GXP_I2CMCMD); + } + } else { + /* Start to write first data to slave */ + if (drvdata->buf_remaining == 0) { + /* No more data to write, stop */ + drvdata->msgs_remaining--; + drvdata->state = GXP_I2C_COMP; + gxp_i2c_stop(drvdata); + return; + } + value = *drvdata->buf; + value = value << 8; + /* Clear master event */ + value |= 0x80; + drvdata->buf++; + drvdata->buf_remaining--; + drvdata->state = GXP_I2C_WDATA_PHASE; + writew(value, drvdata->base + GXP_I2CMCMD); + } +} + +static void gxp_i2c_ack_data(struct gxp_i2c_drvdata *drvdata) +{ + u8 value; + + /* Store the data returned */ + value = readb(drvdata->base + GXP_I2CSNPDAT); + *drvdata->buf = value; + drvdata->buf++; + drvdata->buf_remaining--; + + if (drvdata->buf_remaining == 0) { + /* No more data, this message is completed. */ + drvdata->msgs_remaining--; + + if (drvdata->msgs_remaining == 0) { + /* No more messages, stop */ + drvdata->state = GXP_I2C_COMP; + gxp_i2c_stop(drvdata); + return; + } + /* Move to next message and start transfer */ + drvdata->curr_msg++; + gxp_i2c_restart(drvdata); + return; + } + + /* Ack the slave to make it send next byte */ + drvdata->state = GXP_I2C_RDATA_PHASE; + if (drvdata->buf_remaining == 1) { + /* The last data, do not ack */ + writeb(0x84, drvdata->base + GXP_I2CMCMD); + } else { + /* Read data and ack it */ + writeb(0x8C, drvdata->base + GXP_I2CMCMD); + } +} + +static void gxp_i2c_chk_data_ack(struct gxp_i2c_drvdata *drvdata) +{ + u16 value; + + value = readb(drvdata->base + GXP_I2CSTAT); + if (!(value & MASK_ACK)) { + /* Received No ack, stop */ + drvdata->state = GXP_I2C_DATA_NACK; + gxp_i2c_stop(drvdata); + return; + } + + /* Got ack, check if there is more data to write */ + if (drvdata->buf_remaining == 0) { + /* No more data, this message is completed */ + drvdata->msgs_remaining--; + + if (drvdata->msgs_remaining == 0) { + /* No more messages, stop */ + drvdata->state = GXP_I2C_COMP; + gxp_i2c_stop(drvdata); + return; + } + /* Move to next message and start transfer */ + drvdata->curr_msg++; + gxp_i2c_restart(drvdata); + return; + } + + /* Write data to slave */ + value = *drvdata->buf; + value = value << 8; + + /* Clear master event */ + value |= 0x80; + drvdata->buf++; + drvdata->buf_remaining--; + drvdata->state = GXP_I2C_WDATA_PHASE; + writew(value, drvdata->base + GXP_I2CMCMD); +} + +#if IS_ENABLED(CONFIG_I2C_SLAVE) +static bool gxp_i2c_slave_irq_handler(struct gxp_i2c_drvdata *drvdata) +{ + u8 value; + u8 buf; + int ret; + + value = readb(drvdata->base + GXP_I2CEVTERR); + + /* Received start or stop event */ + if (value & MASK_SLAVE_CMD_EVENT) { + value = readb(drvdata->base + GXP_I2CSTAT); + /* Master sent stop */ + if (value & MASK_STOP_EVENT) { + if (drvdata->stopped == 0) + i2c_slave_event(drvdata->slave, I2C_SLAVE_STOP, &buf); + writeb(0x69, drvdata->base + GXP_I2CSCMD); + drvdata->stopped = 1; + } else { + /* Master sent start and wants to read */ + drvdata->stopped = 0; + if (value & MASK_RW) { + i2c_slave_event(drvdata->slave, + I2C_SLAVE_READ_REQUESTED, &buf); + value = buf << 8 | 0x61; + writew(value, drvdata->base + GXP_I2CSCMD); + } else { + /* Master wants to write to us */ + ret = i2c_slave_event(drvdata->slave, + I2C_SLAVE_WRITE_REQUESTED, &buf); + if (!ret) { + /* Ack next byte from master */ + writeb(0x69, drvdata->base + GXP_I2CSCMD); + } else { + /* Nack next byte from master */ + writeb(0x61, drvdata->base + GXP_I2CSCMD); + } + } + } + } else if (value & MASK_SLAVE_DATA_EVENT) { + value = readb(drvdata->base + GXP_I2CSTAT); + /* Master wants to read */ + if (value & MASK_RW) { + /* Master wants another byte */ + if (value & MASK_ACK) { + i2c_slave_event(drvdata->slave, + I2C_SLAVE_READ_PROCESSED, &buf); + value = buf << 8 | 0x61; + writew(value, drvdata->base + GXP_I2CSCMD); + } else { + /* No more bytes needed */ + writew(0x69, drvdata->base + GXP_I2CSCMD); + } + } else { + /* Master wants to write to us */ + value = readb(drvdata->base + GXP_I2CSNPDAT); + buf = (uint8_t)value; + ret = i2c_slave_event(drvdata->slave, + I2C_SLAVE_WRITE_RECEIVED, &buf); + if (!ret) { + /* Ack next byte from master */ + writeb(0x69, drvdata->base + GXP_I2CSCMD); + } else { + /* Nack next byte from master */ + writeb(0x61, drvdata->base + GXP_I2CSCMD); + } + } + } else { + return false; + } + + return true; +} +#endif + +static irqreturn_t gxp_i2c_irq_handler(int irq, void *_drvdata) +{ + struct gxp_i2c_drvdata *drvdata = (struct gxp_i2c_drvdata *)_drvdata; + u32 value; + + /* Check if the interrupt is for the current engine */ + regmap_read(i2cg_map, GXP_I2CINTSTAT, &value); + if (!(value & BIT(drvdata->engine))) + return IRQ_NONE; + + value = readb(drvdata->base + GXP_I2CEVTERR); + + /* Error */ + if (value & ~(MASK_MASTER_EVENT | MASK_SLAVE_CMD_EVENT | + MASK_SLAVE_DATA_EVENT)) { + /* Clear all events */ + writeb(0x00, drvdata->base + GXP_I2CEVTERR); + drvdata->state = GXP_I2C_ERROR; + gxp_i2c_stop(drvdata); + return IRQ_HANDLED; + } + + if (IS_ENABLED(CONFIG_I2C_SLAVE)) { + /* Slave mode */ + if (value & (MASK_SLAVE_CMD_EVENT | MASK_SLAVE_DATA_EVENT)) { + if (gxp_i2c_slave_irq_handler(drvdata)) + return IRQ_HANDLED; + return IRQ_NONE; + } + } + + /* Master mode */ + switch (drvdata->state) { + case GXP_I2C_ADDR_PHASE: + gxp_i2c_chk_addr_ack(drvdata); + break; + + case GXP_I2C_RDATA_PHASE: + gxp_i2c_ack_data(drvdata); + break; + + case GXP_I2C_WDATA_PHASE: + gxp_i2c_chk_data_ack(drvdata); + break; + } + + return IRQ_HANDLED; +} + +static void gxp_i2c_init(struct gxp_i2c_drvdata *drvdata) +{ + drvdata->state = GXP_I2C_IDLE; + writeb(2000000 / drvdata->t.bus_freq_hz, + drvdata->base + GXP_I2CFREQDIV); + writeb(0x32, drvdata->base + GXP_I2CFLTFAIR); + writeb(0x0a, drvdata->base + GXP_I2CTMOEDG); + writeb(0x00, drvdata->base + GXP_I2CCYCTIM); + writeb(0x00, drvdata->base + GXP_I2CSNPAA); + writeb(0x00, drvdata->base + GXP_I2CADVFEAT); + writeb(0xF0, drvdata->base + GXP_I2CSCMD); + writeb(0x80, drvdata->base + GXP_I2CMCMD); + writeb(0x00, drvdata->base + GXP_I2CEVTERR); + writeb(0x00, drvdata->base + GXP_I2COWNADR); +} + +static int gxp_i2c_probe(struct platform_device *pdev) +{ + struct gxp_i2c_drvdata *drvdata; + int rc; + struct i2c_adapter *adapter; + + if (!i2c_global_init_done) { + i2cg_map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, + "hpe,sysreg"); + if (IS_ERR(i2cg_map)) { + return dev_err_probe(&pdev->dev, IS_ERR(i2cg_map), + "failed to map i2cg_handle\n"); + } + + /* Disable interrupt */ + regmap_update_bits(i2cg_map, GXP_I2CINTEN, 0x00000FFF, 0); + i2c_global_init_done = true; + } + + drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), + GFP_KERNEL); + if (!drvdata) + return -ENOMEM; + + platform_set_drvdata(pdev, drvdata); + drvdata->dev = &pdev->dev; + init_completion(&drvdata->completion); + + drvdata->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(drvdata->base)) + return PTR_ERR(drvdata->base); + + /* Use physical memory address to determine which I2C engine this is. */ + drvdata->engine = ((u32)drvdata->base & 0xf00) >> 8; + + if (drvdata->engine >= GXP_MAX_I2C_ENGINE) { + return dev_err_probe(&pdev->dev, -EINVAL, "i2c engine% is unsupported\n", + drvdata->engine); + } + + rc = platform_get_irq(pdev, 0); + if (rc < 0) + return rc; + + drvdata->irq = rc; + rc = devm_request_irq(&pdev->dev, drvdata->irq, gxp_i2c_irq_handler, + IRQF_SHARED, gxp_i2c_name[drvdata->engine], drvdata); + if (rc < 0) + return dev_err_probe(&pdev->dev, rc, "irq request failed\n"); + + i2c_parse_fw_timings(&pdev->dev, &drvdata->t, true); + + gxp_i2c_init(drvdata); + + /* Enable interrupt */ + regmap_update_bits(i2cg_map, GXP_I2CINTEN, BIT(drvdata->engine), + BIT(drvdata->engine)); + + adapter = &drvdata->adapter; + i2c_set_adapdata(adapter, drvdata); + + adapter->owner = THIS_MODULE; + strscpy(adapter->name, "HPE GXP I2C adapter", sizeof(adapter->name)); + adapter->algo = &gxp_i2c_algo; + adapter->dev.parent = &pdev->dev; + adapter->dev.of_node = pdev->dev.of_node; + + rc = i2c_add_adapter(adapter); + if (rc) + return dev_err_probe(&pdev->dev, rc, "i2c add adapter failed\n"); + + return 0; +} + +static int gxp_i2c_remove(struct platform_device *pdev) +{ + struct gxp_i2c_drvdata *drvdata = platform_get_drvdata(pdev); + + disable_irq(drvdata->irq); + i2c_del_adapter(&drvdata->adapter); + + return 0; +} + +static const struct of_device_id gxp_i2c_of_match[] = { + { .compatible = "hpe,gxp-i2c" }, + {}, +}; +MODULE_DEVICE_TABLE(of, gxp_i2c_of_match); + +static struct platform_driver gxp_i2c_driver = { + .probe = gxp_i2c_probe, + .remove = gxp_i2c_remove, + .driver = { + .name = "gxp-i2c", + .of_match_table = gxp_i2c_of_match, + }, +}; +module_platform_driver(gxp_i2c_driver); + +MODULE_AUTHOR("Nick Hawkins "); +MODULE_DESCRIPTION("HPE GXP I2C bus driver"); +MODULE_LICENSE("GPL");