Add HiSilicon I2C controller driver for the Kunpeng SoC. It provides the access to the i2c busses, which connects to the eeprom, rtc, etc. The driver works with IRQ mode, and supports basic I2C features and 10bit address. The DMA is not supported. Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> --- drivers/i2c/busses/Kconfig | 10 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-hisi.c | 525 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 536 insertions(+) create mode 100644 drivers/i2c/busses/i2c-hisi.c diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 05ebf75..f6b8b71 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -645,6 +645,16 @@ config I2C_HIGHLANDER This driver can also be built as a module. If so, the module will be called i2c-highlander. +config I2C_HISI + tristate "HiSilicon I2C controller" + depends on (ARM64 && ACPI) || COMPILE_TEST + help + Say Y here if you want to have Hisilicon I2C controller support + available on the Kunpeng Server. + + This driver can also be built as a module. If so, the module + will be called i2c-hisi. + config I2C_IBM_IIC tristate "IBM PPC 4xx on-chip I2C interface" depends on 4xx diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 615f35e..e1c9292 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -63,6 +63,7 @@ obj-$(CONFIG_I2C_EMEV2) += i2c-emev2.o obj-$(CONFIG_I2C_EXYNOS5) += i2c-exynos5.o obj-$(CONFIG_I2C_GPIO) += i2c-gpio.o obj-$(CONFIG_I2C_HIGHLANDER) += i2c-highlander.o +obj-$(CONFIG_I2C_HISI) += i2c-hisi.o obj-$(CONFIG_I2C_HIX5HD2) += i2c-hix5hd2.o obj-$(CONFIG_I2C_IBM_IIC) += i2c-ibm_iic.o obj-$(CONFIG_I2C_IMG) += i2c-img-scb.o diff --git a/drivers/i2c/busses/i2c-hisi.c b/drivers/i2c/busses/i2c-hisi.c new file mode 100644 index 0000000..6cfeff3 --- /dev/null +++ b/drivers/i2c/busses/i2c-hisi.c @@ -0,0 +1,525 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * HiSilicon I2C Controller Driver for Kunpeng SoC + * + * Copyright (c) 2021 HiSilicon Limited. + */ + +#include <linux/acpi.h> +#include <linux/bits.h> +#include <linux/bitfield.h> +#include <linux/completion.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/platform_device.h> + +#define HISI_I2C_FRAME_CTRL 0x0000 +#define HISI_I2C_FRAME_CTRL_SPEED_MODE GENMASK(1, 0) +#define HISI_I2C_FRAME_CTRL_ADDR_TEN BIT(2) +#define HISI_I2C_SLV_ADDR 0x0004 +#define HISI_I2C_SLV_ADDR_VAL GENMASK(9, 0) +#define HISI_I2C_SLV_ADDR_GC_S_MODE BIT(10) +#define HISI_I2C_SLV_ADDR_GC_S_EN BIT(11) +#define HISI_I2C_CMD_TXDATA 0x0008 +#define HISI_I2C_CMD_TXDATA_DATA GENMASK(7, 0) +#define HISI_I2C_CMD_TXDATA_RW BIT(8) +#define HISI_I2C_CMD_TXDATA_P_EN BIT(9) +#define HISI_I2C_CMD_TXDATA_SR_EN BIT(10) +#define HISI_I2C_RXDATA 0x000c +#define HISI_I2C_RXDATA_DATA GENMASK(7, 0) +#define HISI_I2C_SS_SCL_HCNT 0x0010 +#define HISI_I2C_SS_SCL_LCNT 0x0014 +#define HISI_I2C_FS_SCL_HCNT 0x0018 +#define HISI_I2C_FS_SCL_LCNT 0x001c +#define HISI_I2C_HS_SCL_HCNT 0x0020 +#define HISI_I2C_HS_SCL_LCNT 0x0024 +#define HISI_I2C_FIFO_CTRL 0x0028 +#define HISI_I2C_FIFO_RX_CLR BIT(0) +#define HISI_I2C_FIFO_TX_CLR BIT(1) +#define HISI_I2C_FIFO_RX_AF_THRESH GENMASK(7, 2) +#define HISI_I2C_FIFO_TX_AE_THRESH GENMASK(13, 8) +#define HISI_I2C_FIFO_STATE 0x002c +#define HISI_I2C_FIFO_STATE_RX_RERR BIT(0) +#define HISI_I2C_FIFO_STATE_RX_WERR BIT(1) +#define HISI_I2C_FIFO_STATE_RX_EMPTY BIT(3) +#define HISI_I2C_FIFO_STATE_TX_RERR BIT(6) +#define HISI_I2C_FIFO_STATE_TX_WERR BIT(7) +#define HISI_I2C_FIFO_STATE_TX_FULL BIT(11) +#define HISI_I2C_SDA_HOLD 0x0030 +#define HISI_I2C_SDA_HOLD_TX GENMASK(15, 0) +#define HISI_I2C_SDA_HOLD_RX GENMASK(23, 16) +#define HISI_I2C_FS_SPK_LEN 0x0038 +#define HISI_I2C_FS_SPK_LEN_CNT GENMASK(7, 0) +#define HISI_I2C_HS_SPK_LEN 0x003c +#define HISI_I2C_HS_SPK_LEN_CNT GENMASK(7, 0) +#define HISI_I2C_INT_MSTAT 0x0044 +#define HISI_I2C_INT_CLR 0x0048 +#define HISI_I2C_INT_MASK 0x004C +#define HISI_I2C_TRANS_STATE 0x0050 +#define HISI_I2C_TRANS_ERR 0x0054 +#define HISI_I2C_VERSION 0x0058 + +#define HISI_I2C_INT_ALL 0x1f +#define HISI_I2C_INT_TRANS_CPLT BIT(0) +#define HISI_I2C_INT_TRANS_ERR BIT(1) +#define HISI_I2C_INT_FIFO_ERR BIT(2) +#define HISI_I2C_INT_RX_FULL BIT(3) +#define HISI_I2C_INT_TX_EMPTY BIT(4) +#define HISI_I2C_INT_ERR (HISI_I2C_INT_TRANS_ERR | \ + HISI_I2C_INT_FIFO_ERR) + +#define HISI_I2C_STD_SPEED_MODE 0x0 +#define HISI_I2C_FAST_SPEED_MODE 0x1 +#define HISI_I2C_HIGH_SPEED_MODE 0x2 + +#define HISI_I2C_TX_FIFO_DEPTH 64 +#define HISI_I2C_RX_FIFO_DEPTH 64 +#define HISI_I2C_TX_F_AE_THRESH 1 +#define HISI_I2C_RX_F_AF_THRESH 60 + +#define NSEC_TO_CYCLES(ns, clk_rate_khz) (DIV_ROUND_UP_ULL((clk_rate_khz) * (ns), NSEC_PER_MSEC)) + +struct hisi_i2c_controller { + struct device *dev; + struct i2c_adapter adapter; + void __iomem *iobase; + int irq; + + /* Intermediates for recording the transfer process */ + struct completion *completion; + struct i2c_msg *msgs; + int msg_num; + int msg_tx_idx; + int buf_tx_idx; + int msg_rx_idx; + int buf_rx_idx; + u16 tar_addr; + u32 xfer_err; + + /* I2C bus configuration */ + u32 scl_fall_time; + u32 scl_rise_time; + u32 sda_hold_time; + u64 clk_rate_khz; + u32 bus_freq_hz; + u32 spk_len; +}; + +static const char *hisi_i2c_speed_string(u32 bus_freq_hz) +{ + switch (bus_freq_hz) { + case I2C_MAX_STANDARD_MODE_FREQ: + return "100K"; + case I2C_MAX_FAST_MODE_FREQ: + return "400K"; + case I2C_MAX_HIGH_SPEED_MODE_FREQ: + return "3.4M"; + default: + return "unknown"; + } +} + +static void hisi_i2c_enable_int(struct hisi_i2c_controller *ctlr, u32 mask) +{ + writel(mask, ctlr->iobase + HISI_I2C_INT_MASK); +} + +static void hisi_i2c_disable_int(struct hisi_i2c_controller *ctlr, u32 mask) +{ + writel((~mask) & HISI_I2C_INT_ALL, ctlr->iobase + HISI_I2C_INT_MASK); +} + +static void hisi_i2c_clear_int(struct hisi_i2c_controller *ctlr, u32 mask) +{ + writel(mask, ctlr->iobase + HISI_I2C_INT_CLR); +} + +static void hisi_i2c_handle_errors(struct hisi_i2c_controller *ctlr) +{ + u32 int_err = ctlr->xfer_err, reg; + + if (int_err & HISI_I2C_INT_FIFO_ERR) { + reg = readl(ctlr->iobase + HISI_I2C_FIFO_STATE); + + if (reg & HISI_I2C_FIFO_STATE_RX_RERR) + dev_err(ctlr->dev, "rx fifo error read.\n"); + + if (reg & HISI_I2C_FIFO_STATE_RX_WERR) + dev_err(ctlr->dev, "rx fifo error write.\n"); + + if (reg & HISI_I2C_FIFO_STATE_TX_RERR) + dev_err(ctlr->dev, "tx fifo error read.\n"); + + if (reg & HISI_I2C_FIFO_STATE_TX_WERR) + dev_err(ctlr->dev, "tx fifo error write.\n"); + } +} + +static int hisi_i2c_start_xfer(struct hisi_i2c_controller *ctlr) +{ + struct i2c_msg *msg = ctlr->msgs; + u32 reg; + + reg = readl(ctlr->iobase + HISI_I2C_FRAME_CTRL); + reg &= ~HISI_I2C_FRAME_CTRL_ADDR_TEN; + if (msg->flags & I2C_M_TEN) + reg |= HISI_I2C_FRAME_CTRL_ADDR_TEN; + writel(reg, ctlr->iobase + HISI_I2C_FRAME_CTRL); + + reg = readl(ctlr->iobase + HISI_I2C_SLV_ADDR); + reg &= ~HISI_I2C_SLV_ADDR_VAL; + reg |= FIELD_PREP(HISI_I2C_SLV_ADDR_VAL, msg->addr); + writel(reg, ctlr->iobase + HISI_I2C_SLV_ADDR); + + reg = readl(ctlr->iobase + HISI_I2C_FIFO_CTRL); + reg |= HISI_I2C_FIFO_RX_CLR | HISI_I2C_FIFO_TX_CLR; + writel(reg, ctlr->iobase + HISI_I2C_FIFO_CTRL); + reg &= ~(HISI_I2C_FIFO_RX_CLR | HISI_I2C_FIFO_TX_CLR); + writel(reg, ctlr->iobase + HISI_I2C_FIFO_CTRL); + + hisi_i2c_clear_int(ctlr, HISI_I2C_INT_ALL); + hisi_i2c_enable_int(ctlr, HISI_I2C_INT_ALL); + + return 0; +} + +static void hisi_i2c_reset_xfer(struct hisi_i2c_controller *ctlr) +{ + ctlr->msg_num = 0; + ctlr->xfer_err = 0; + ctlr->msg_tx_idx = 0; + ctlr->msg_rx_idx = 0; + ctlr->buf_tx_idx = 0; + ctlr->buf_rx_idx = 0; +} + +/* + * Initialize the transfer information and start the I2C bus transfer. + * We only configure the transfer and do some pre/post works here, and + * wait for the transfer done. The major transfer process is performed + * in the IRQ handler. + */ +static int hisi_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, + int num) +{ + struct hisi_i2c_controller *ctlr = i2c_get_adapdata(adap); + DECLARE_COMPLETION_ONSTACK(done); + int ret = num; + + hisi_i2c_reset_xfer(ctlr); + ctlr->completion = &done; + ctlr->msg_num = num; + ctlr->msgs = msgs; + + hisi_i2c_start_xfer(ctlr); + + if (!wait_for_completion_timeout(ctlr->completion, adap->timeout)) { + hisi_i2c_disable_int(ctlr, HISI_I2C_INT_ALL); + i2c_recover_bus(&ctlr->adapter); + dev_err(ctlr->dev, "bus transfer timeout\n"); + ret = -EIO; + } + + if (ctlr->xfer_err) { + hisi_i2c_handle_errors(ctlr); + ret = -EIO; + } + + hisi_i2c_reset_xfer(ctlr); + ctlr->completion = NULL; + + return ret; +} + +static u32 hisi_i2c_functionality(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL; +} + +static const struct i2c_algorithm hisi_i2c_algo = { + .master_xfer = hisi_i2c_master_xfer, + .functionality = hisi_i2c_functionality, +}; + +static int hisi_i2c_read_rx_fifo(struct hisi_i2c_controller *ctlr) +{ + struct i2c_msg *cur_msg; + u32 fifo_state; + + while (ctlr->msg_rx_idx < ctlr->msg_num) { + cur_msg = ctlr->msgs + ctlr->msg_rx_idx; + + if (!(cur_msg->flags & I2C_M_RD)) { + ctlr->msg_rx_idx++; + continue; + } + + fifo_state = readl(ctlr->iobase + HISI_I2C_FIFO_STATE); + while (!(fifo_state & HISI_I2C_FIFO_STATE_RX_EMPTY) && + ctlr->buf_rx_idx < cur_msg->len) { + cur_msg->buf[ctlr->buf_rx_idx++] = readl(ctlr->iobase + HISI_I2C_RXDATA); + fifo_state = readl(ctlr->iobase + HISI_I2C_FIFO_STATE); + } + + if (ctlr->buf_rx_idx == cur_msg->len) { + ctlr->buf_rx_idx = 0; + ctlr->msg_rx_idx++; + } + + if (fifo_state & HISI_I2C_FIFO_STATE_RX_EMPTY) + break; + } + + return 0; +} + +static void hisi_i2c_xfer_msg(struct hisi_i2c_controller *ctlr) +{ + int max_write = HISI_I2C_TX_FIFO_DEPTH; + bool need_restart = false, last_msg; + struct i2c_msg *cur_msg; + u32 cmd, fifo_state; + + while (ctlr->msg_tx_idx < ctlr->msg_num) { + cur_msg = ctlr->msgs + ctlr->msg_tx_idx; + last_msg = (ctlr->msg_tx_idx == ctlr->msg_num - 1); + + /* Signal the SR bit when we start transferring a new message */ + if (ctlr->msg_tx_idx && !ctlr->buf_tx_idx) + need_restart = true; + + fifo_state = readl(ctlr->iobase + HISI_I2C_FIFO_STATE); + while (!(fifo_state & HISI_I2C_FIFO_STATE_TX_FULL) && + ctlr->buf_tx_idx < cur_msg->len && + max_write) { + cmd = 0; + + if (need_restart) { + cmd |= HISI_I2C_CMD_TXDATA_SR_EN; + need_restart = false; + } + + /* Signal the STOP bit at the last frame of the last message */ + if (ctlr->buf_tx_idx == cur_msg->len - 1 && + last_msg) + cmd |= HISI_I2C_CMD_TXDATA_P_EN; + + if (cur_msg->flags & I2C_M_RD) + cmd |= HISI_I2C_CMD_TXDATA_RW; + else + cmd |= FIELD_PREP(HISI_I2C_CMD_TXDATA_DATA, + cur_msg->buf[ctlr->buf_tx_idx]); + + writel(cmd, ctlr->iobase + HISI_I2C_CMD_TXDATA); + ctlr->buf_tx_idx++; + max_write--; + + fifo_state = readl(ctlr->iobase + HISI_I2C_FIFO_STATE); + } + + /* Update the transfer index after per message transfer is done. */ + if (ctlr->buf_tx_idx == cur_msg->len) { + ctlr->buf_tx_idx = 0; + ctlr->msg_tx_idx++; + } + + if ((fifo_state & HISI_I2C_FIFO_STATE_TX_FULL) || + max_write == 0) + break; + } +} + +static irqreturn_t hisi_i2c_irq(int irq, void *context) +{ + struct hisi_i2c_controller *ctlr = context; + u32 int_stat; + + int_stat = readl(ctlr->iobase + HISI_I2C_INT_MSTAT); + hisi_i2c_clear_int(ctlr, int_stat); + if (!(int_stat & HISI_I2C_INT_ALL)) + return IRQ_NONE; + + if (int_stat & HISI_I2C_INT_TX_EMPTY) + hisi_i2c_xfer_msg(ctlr); + + if (int_stat & HISI_I2C_INT_ERR) { + ctlr->xfer_err = int_stat; + goto out; + } + + /* Drain the rx fifo before finish the transfer */ + if (int_stat & (HISI_I2C_INT_TRANS_CPLT | HISI_I2C_INT_RX_FULL)) + hisi_i2c_read_rx_fifo(ctlr); + +out: + if (int_stat & HISI_I2C_INT_TRANS_CPLT || ctlr->xfer_err) { + hisi_i2c_disable_int(ctlr, HISI_I2C_INT_ALL); + hisi_i2c_clear_int(ctlr, HISI_I2C_INT_ALL); + complete(ctlr->completion); + } + + return IRQ_HANDLED; +} + +/* + * Helper function for calculating and configuring the HIGH and LOW + * periods of SCL clock. The caller will pass the ratio of the + * counts (divide / divisor) according to the target speed mode, + * and the target registers. + */ +static void hisi_i2c_set_scl(struct hisi_i2c_controller *ctlr, + u32 divide, u32 divisor, + u32 reg_hcnt, u32 reg_lcnt) +{ + u32 total_cnt, t_scl_hcnt, t_scl_lcnt, scl_fall_cnt, scl_rise_cnt; + u32 scl_hcnt, scl_lcnt; + + /* Total SCL clock cycles per speed period */ + total_cnt = DIV_ROUND_UP_ULL(ctlr->clk_rate_khz * 1000, ctlr->bus_freq_hz); + /* Total HIGH level SCL clock cycles including edges */ + t_scl_hcnt = DIV_ROUND_UP_ULL(total_cnt * divide, divisor); + /* Total LOW level SCL clock cycles including edges */ + t_scl_lcnt = total_cnt - t_scl_hcnt; + /* Fall edge SCL clock cycles */ + scl_fall_cnt = NSEC_TO_CYCLES(ctlr->scl_fall_time, ctlr->clk_rate_khz); + /* Rise edge SCL clock cycles */ + scl_rise_cnt = NSEC_TO_CYCLES(ctlr->scl_rise_time, ctlr->clk_rate_khz); + + /* Calculated HIGH and LOW periods of SCL clock */ + scl_hcnt = t_scl_hcnt - ctlr->spk_len - 7 - scl_fall_cnt; + scl_lcnt = t_scl_lcnt - 1 - scl_rise_cnt; + + writel(scl_hcnt, ctlr->iobase + reg_hcnt); + writel(scl_lcnt, ctlr->iobase + reg_lcnt); +} + +static void hisi_i2c_configure_bus(struct hisi_i2c_controller *ctlr) +{ + u32 reg, sda_hold_cnt, speed_mode; + struct i2c_timings t; + + i2c_parse_fw_timings(ctlr->dev, &t, true); + ctlr->bus_freq_hz = t.bus_freq_hz; + ctlr->spk_len = NSEC_TO_CYCLES(t.digital_filter_width_ns, ctlr->clk_rate_khz); + ctlr->scl_fall_time = t.scl_fall_ns; + ctlr->scl_rise_time = t.scl_rise_ns; + ctlr->sda_hold_time = t.sda_hold_ns; + + switch (ctlr->bus_freq_hz) { + case I2C_MAX_FAST_MODE_FREQ: + speed_mode = HISI_I2C_FAST_SPEED_MODE; + hisi_i2c_set_scl(ctlr, 26, 76, HISI_I2C_FS_SCL_HCNT, HISI_I2C_FS_SCL_LCNT); + break; + case I2C_MAX_HIGH_SPEED_MODE_FREQ: + speed_mode = HISI_I2C_HIGH_SPEED_MODE; + hisi_i2c_set_scl(ctlr, 6, 22, HISI_I2C_HS_SCL_HCNT, HISI_I2C_HS_SCL_LCNT); + break; + case I2C_MAX_STANDARD_MODE_FREQ: + default: + speed_mode = HISI_I2C_STD_SPEED_MODE; + + /* For default condition force the bus speed to standard mode. */ + ctlr->bus_freq_hz = I2C_MAX_STANDARD_MODE_FREQ; + hisi_i2c_set_scl(ctlr, 40, 87, HISI_I2C_SS_SCL_HCNT, HISI_I2C_SS_SCL_LCNT); + break; + } + + reg = readl(ctlr->iobase + HISI_I2C_FRAME_CTRL); + reg &= ~HISI_I2C_FRAME_CTRL_SPEED_MODE; + reg |= FIELD_PREP(HISI_I2C_FRAME_CTRL_SPEED_MODE, speed_mode); + writel(reg, ctlr->iobase + HISI_I2C_FRAME_CTRL); + + sda_hold_cnt = NSEC_TO_CYCLES(ctlr->sda_hold_time, ctlr->clk_rate_khz); + + reg = FIELD_PREP(HISI_I2C_SDA_HOLD_TX, sda_hold_cnt); + writel(reg, ctlr->iobase + HISI_I2C_SDA_HOLD); + + writel(ctlr->spk_len, ctlr->iobase + HISI_I2C_FS_SPK_LEN); + + reg = FIELD_PREP(HISI_I2C_FIFO_RX_AF_THRESH, HISI_I2C_RX_F_AF_THRESH); + reg |= FIELD_PREP(HISI_I2C_FIFO_TX_AE_THRESH, HISI_I2C_TX_F_AE_THRESH); + writel(reg, ctlr->iobase + HISI_I2C_FIFO_CTRL); +} + +static int hisi_i2c_probe(struct platform_device *pdev) +{ + struct hisi_i2c_controller *ctlr; + struct device *dev = &pdev->dev; + struct i2c_adapter *adapter; + u32 hw_version; + int ret; + + ctlr = devm_kzalloc(dev, sizeof(*ctlr), GFP_KERNEL); + if (!ctlr) + return -ENOMEM; + + ctlr->dev = dev; + ctlr->iobase = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(ctlr->iobase)) + return PTR_ERR(ctlr->iobase); + + ctlr->irq = platform_get_irq(pdev, 0); + if (ctlr->irq <= 0) + return -ENOENT; + + hisi_i2c_disable_int(ctlr, HISI_I2C_INT_ALL); + + ret = devm_request_irq(dev, ctlr->irq, hisi_i2c_irq, + 0, "hisi-i2c", ctlr); + if (ret) { + dev_err(dev, "failed to request irq handler, ret = %d.\n", ret); + return ret; + } + + ret = device_property_read_u64(dev, "clk_rate", &ctlr->clk_rate_khz); + if (ret) { + dev_err(dev, "failed to get clock frequency, ret = %d.\n", ret); + return ret; + } + ctlr->clk_rate_khz = DIV_ROUND_UP_ULL(ctlr->clk_rate_khz, 1000); + + hisi_i2c_configure_bus(ctlr); + + adapter = &ctlr->adapter; + snprintf(adapter->name, sizeof(adapter->name), + "HiSilicon I2C Controller %s", dev_name(dev)); + adapter->owner = THIS_MODULE; + adapter->algo = &hisi_i2c_algo; + adapter->dev.parent = dev; + i2c_set_adapdata(adapter, ctlr); + + ret = devm_i2c_add_adapter(dev, adapter); + if (ret) { + dev_err(dev, "failed to add i2c adapter, ret = %d.\n", ret); + return ret; + } + + hw_version = readl(ctlr->iobase + HISI_I2C_VERSION); + dev_info(ctlr->dev, "speed mode %s. hw version 0x%x.\n", + hisi_i2c_speed_string(ctlr->bus_freq_hz), hw_version); + + return 0; +} + +static const struct acpi_device_id hisi_i2c_acpi_ids[] = { + { "HISI03D1", 0 }, + { } +}; +MODULE_DEVICE_TABLE(acpi, hisi_i2c_acpi_ids); +MODULE_ALIAS("platform:hisi-i2c"); + +static struct platform_driver hisi_i2c_driver = { + .probe = hisi_i2c_probe, + .driver = { + .name = "hisi-i2c", + .acpi_match_table = hisi_i2c_acpi_ids, + }, +}; + +module_platform_driver(hisi_i2c_driver); + +MODULE_AUTHOR("Yicong Yang <yangyicong@hisilicon.com>"); +MODULE_DESCRIPTION("HiSilicon I2C Controller Driver"); +MODULE_LICENSE("GPL"); -- 2.8.1

-----Original Message----- From: Yicong Yang [mailto:yangyicong@hisilicon.com] Sent: Wednesday, March 10, 2021 2:22 AM To: wsa@kernel.org; linux-i2c@vger.kernel.org Cc: linuxarm@openeuler.org; Zengtao (B) <prime.zeng@hisilicon.com>; yangyicong <yangyicong@huawei.com> Subject: [Linuxarm] [PATCH v2 1/3] i2c: core: add managed function for adding i2c adapters

Some I2C controller drivers will only unregister the I2C adapter in their .remove() callback, which can be done by simply using a managed variant to add the I2C adapter.

So add the managed functions for adding the I2C adapter.

Sounds like a very useful wrapper. We are able to remove some "remove" callbacks afterwards. We have some similar wrappers like devm_hwrng_register which is always helpful.

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> --- drivers/i2c/i2c-core-base.c | 39 +++++++++++++++++++++++++++++++++++++++ include/linux/i2c.h | 1 + 2 files changed, 40 insertions(+)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 63ebf72..61486dc 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -1550,6 +1550,38 @@ int i2c_add_adapter(struct i2c_adapter *adapter) } EXPORT_SYMBOL(i2c_add_adapter);

+static void devm_i2c_del_adapter(struct device *dev, void *ptr); + +/** + * devm_i2c_add_adapter - device-managed variant of i2c_add_adapter() + * @dev: managing device for adding this I2C adapter + * @adapter: the adapter to add + * Context: can sleep + * + * Add adapter with dynamic bus number, same with i2c_add_adapter() + * but the adapter will be auto deleted on driver detach. + */ +int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter) +{ + struct i2c_adapter **ptr; + int ret; + + ptr = devres_alloc(devm_i2c_del_adapter, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return -ENOMEM; + + ret = i2c_add_adapter(adapter); + if (!ret) { + *ptr = adapter; + devres_add(dev, ptr); + } else { + devres_free(ptr); + } + + return ret; +} +EXPORT_SYMBOL(devm_i2c_add_adapter); + /** * i2c_add_numbered_adapter - declare i2c adapter, use static bus number * @adap: the adapter to register (with adap->nr initialized) @@ -1703,6 +1735,13 @@ void i2c_del_adapter(struct i2c_adapter *adap) } EXPORT_SYMBOL(i2c_del_adapter);

+static void devm_i2c_del_adapter(struct device *dev, void *ptr) +{ + struct i2c_adapter *adapter = *((struct i2c_adapter **)ptr); + + i2c_del_adapter(adapter); +} + static void i2c_parse_timing(struct device *dev, char *prop_name, u32 *cur_val_p, u32 def_val, bool use_def) { diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 5662265..10bd0b0 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -844,6 +844,7 @@ static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap) */ #if IS_ENABLED(CONFIG_I2C) int i2c_add_adapter(struct i2c_adapter *adap); +int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter); void i2c_del_adapter(struct i2c_adapter *adap); int i2c_add_numbered_adapter(struct i2c_adapter *adap);

-- 2.8.1

Thanks Barry