This patch introduces basic I2C support for the SpacemiT K1 SoC,
utilizing interrupts for transfers.
The driver has been tested using i2c-tools on a Bananapi-F3 board,
and basic I2C read/write operations have been confirmed to work.
Signed-off-by: Troy Mitchell <TroyMitchell988@xxxxxxxxx>
---
drivers/i2c/busses/Kconfig | 18 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-k1.c | 694 ++++++++++++++++++++++++++++++++++++
3 files changed, 713 insertions(+)
create mode 100644 drivers/i2c/busses/i2c-k1.c
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 53f18b351f53..cfa5cda9c8d8 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -800,6 +800,24 @@ config I2C_KEMPLD
This driver can also be built as a module. If so, the module
will be called i2c-kempld.
+config I2C_K1
+ tristate "Spacemit K1 I2C adapter"
+ depends on ARCH_SPACEMIT || COMPILE_TEST
+ help
+ This option enables support for the I2C interface on the Spacemit K1
+ platform.
+
+ If you enable this configuration, the kernel will include support for
+ the I2C adapter specific to the Spacemit K1 platform. This driver ca
+ be used to manage I2C bus transactions, which are necessary for
+ interfacing with I2C peripherals such as sensors, EEPROMs, and other
+ devices.
+
+ This driver can also be compiled as a module. If you choose to build
+ it as a module, the resulting kernel module will be named `i2c-k1`.
+ Loading this module will enable the I2C functionality for the K1
+ platform dynamically, without requiring a rebuild of the kernel.
+
config I2C_LPC2K
tristate "I2C bus support for NXP LPC2K/LPC178x/18xx/43xx"
depends on OF && (ARCH_LPC18XX || COMPILE_TEST)
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index ecc07c50f2a0..682e10435a7f 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -78,6 +78,7 @@ obj-$(CONFIG_I2C_IOP3XX) += i2c-iop3xx.o
obj-$(CONFIG_I2C_JZ4780) += i2c-jz4780.o
obj-$(CONFIG_I2C_KEBA) += i2c-keba.o
obj-$(CONFIG_I2C_KEMPLD) += i2c-kempld.o
+obj-$(CONFIG_I2C_K1) += i2c-k1.o
obj-$(CONFIG_I2C_LPC2K) += i2c-lpc2k.o
obj-$(CONFIG_I2C_LS2X) += i2c-ls2x.o
obj-$(CONFIG_I2C_MESON) += i2c-meson.o
diff --git a/drivers/i2c/busses/i2c-k1.c b/drivers/i2c/busses/i2c-k1.c
new file mode 100644
index 000000000000..85053530d9b0
--- /dev/null
+++ b/drivers/i2c/busses/i2c-k1.c
@@ -0,0 +1,694 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2024 Troy Mitchell <troymitchell988@xxxxxxxxx>
+ */
+
+ #include <linux/clk.h>
+ #include <linux/i2c.h>
+ #include <linux/iopoll.h>
+ #include <linux/module.h>
+ #include <linux/of_address.h>
+ #include <linux/platform_device.h>
+
+/* spacemit i2c registers */
+#define ICR 0x0 /* Control Register */
+#define ISR 0x4 /* Status Register */
+#define ISAR 0x8 /* Slave Address Register */
+#define IDBR 0xc /* Data Buffer Register */
+#define ILCR 0x10 /* Load Count Register */
+#define IWCR 0x14 /* Wait Count Register */
+#define IRST_CYC 0x18 /* Bus reset cycle counter */
+#define IBMR 0x1c /* Bus monitor register */
+#define IWFIFO 0x20 /* Write FIFO Register */
+#define IWFIFO_WPTR 0x24 /* Write FIFO Write Pointer Register */
+#define IWFIFO_RPTR 0x28 /* Write FIFO Read Pointer Register */
+#define IRFIFO 0x2c /* Read FIFO Register */
+#define IRFIFO_WPTR 0x30 /* Read FIFO Write Pointer Register */
+#define IRFIFO_RPTR 0x34 /* Read FIFO Read Pointer Register */
+
+/* register ICR fields */
+#define CR_START BIT(0) /* start bit */
+#define CR_STOP BIT(1) /* stop bit */
+#define CR_ACKNAK BIT(2) /* send ACK(0) or NAK(1) */
+#define CR_TB BIT(3) /* transfer byte bit */
+#define CR_TXBEGIN BIT(4) /* transaction begin */
+#define CR_FIFOEN BIT(5) /* enable FIFO mode */
+#define CR_GPIOEN BIT(6) /* enable GPIO mode for SCL in HS */
+#define CR_DMAEN BIT(7) /* enable DMA for TX and RX FIFOs */
+#define CR_MODE_FAST BIT(8) /* bus mode (master operation) */
+#define CR_MODE_HIGH BIT(9) /* bus mode (master operation) */
+#define CR_UR BIT(10) /* unit reset */
+#define CR_RSTREQ BIT(11) /* i2c bus reset request */
+#define CR_MA BIT(12) /* master abort */
+#define CR_SCLE BIT(13) /* master clock enable */
+#define CR_IUE BIT(14) /* unit enable */
+#define CR_HS_STRETCH BIT(16) /* I2C hs stretch */
+#define CR_ALDIE BIT(18) /* enable arbitration interrupt */
+#define CR_DTEIE BIT(19) /* enable tx interrupts */
+#define CR_DRFIE BIT(20) /* enable rx interrupts */
+#define CR_GCD BIT(21) /* general call disable */
+#define CR_BEIE BIT(22) /* enable bus error ints */
+#define CR_SADIE BIT(23) /* slave address detected int enable */
+#define CR_SSDIE BIT(24) /* slave STOP detected int enable */
+#define CR_MSDIE BIT(25) /* master STOP detected int enable */
+#define CR_MSDE BIT(26) /* master STOP detected enable */
+#define CR_TXDONEIE BIT(27) /* transaction done int enable */
+#define CR_TXEIE BIT(28) /* transmit FIFO empty int enable */
+#define CR_RXHFIE BIT(29) /* receive FIFO half-full int enable */
+#define CR_RXFIE BIT(30) /* receive FIFO full int enable */
+#define CR_RXOVIE BIT(31) /* receive FIFO overrun int enable */
+
+/* register ISR fields */
+#define SR_RWM BIT(13) /* read/write mode */
+#define SR_ACKNAK BIT(14) /* ACK/NACK status */
+#define SR_UB BIT(15) /* unit busy */
+#define SR_IBB BIT(16) /* i2c bus busy */
+#define SR_EBB BIT(17) /* early bus busy */
+#define SR_ALD BIT(18) /* arbitration loss detected */
+#define SR_ITE BIT(19) /* tx buffer empty */
+#define SR_IRF BIT(20) /* rx buffer full */
+#define SR_GCAD BIT(21) /* general call address detected */
+#define SR_BED BIT(22) /* bus error no ACK/NAK */
+#define SR_SAD BIT(23) /* slave address detected */
+#define SR_SSD BIT(24) /* slave stop detected */
+#define SR_MSD BIT(26) /* master stop detected */
+#define SR_TXDONE BIT(27) /* transaction done */
+#define SR_TXE BIT(28) /* tx FIFO empty */
+#define SR_RXHF BIT(29) /* rx FIFO half-full */
+#define SR_RXF BIT(30) /* rx FIFO full */
+#define SR_RXOV BIT(31) /* RX FIFO overrun */
+
+/* register ILCR fields */
+#define LCR_SLV 0x000001FF /* SLV: bit[8:0] */
+#define LCR_FLV 0x0003FE00 /* FLV: bit[17:9] */
+#define LCR_HLVH 0x07FC0000 /* HLVH: bit[26:18] */
+#define LCR_HLVL 0xF8000000 /* HLVL: bit[31:27] */
+
+/* register IWCR fields */
+#define WCR_COUNT 0x0000001F /* COUNT: bit[4:0] */
+#define WCR_COUNT1 0x000003E0 /* HS_COUNT1: bit[9:5] */
+#define WCR_COUNT2 0x00007C00 /* HS_COUNT2: bit[14:10] */
+
+/* register IBMR fields */
+#define BMR_SDA BIT(0) /* SDA line level */
+#define BMR_SCL BIT(1) /* SCL line level */
+
+/* register IWFIFO fields */
+#define WFIFO_DATA_MSK 0x000000FF /* data: bit[7:0] */
+#define WFIFO_CTRL_MSK 0x000003E0 /* control: bit[11:8] */
+#define WFIFO_CTRL_START BIT(8) /* start bit */
+#define WFIFO_CTRL_STOP BIT(9) /* stop bit */
+#define WFIFO_CTRL_ACKNAK BIT(10) /* send ACK(0) or NAK(1) */
+#define WFIFO_CTRL_TB BIT(11) /* transfer byte bit */
+
+/* status register init value */
+#define I2C_INT_STATUS_MASK 0xfffc0000 /* SR bits[31:18] */
+#define I2C_INT_CTRL_MASK (CR_ALDIE | CR_DTEIE | CR_DRFIE | \
+ CR_BEIE | CR_TXDONEIE | CR_TXEIE | \
+ CR_RXHFIE | CR_RXFIE | CR_RXOVIE | \
+ CR_MSDIE)
+
+/* i2c bus recover timeout: us */
+#define I2C_BUS_RECOVER_TIMEOUT (100000)
+
+#define I2C_FAST_MODE_FREQ (400000)
+
+enum spacemit_i2c_state {
+ STATE_IDLE,
+ STATE_START,
+ STATE_READ,
+ STATE_WRITE,
+};
+
+enum spacemit_i2c_dir {
+ DIR_WRITE,
+ DIR_READ
+};
+
+/* i2c-spacemit driver's main struct */
+struct spacemit_i2c_dev {
+ struct device *dev;
+ struct i2c_adapter adapt;
+
+ /* hardware resources */
+ void __iomem *base;
+ int irq;
+
+ struct i2c_msg *msgs;
+ int msg_num;
+ struct i2c_msg *cur_msg;
+
+ /* index of the current message being processed */
+ int msg_idx;
+ u8 *msg_buf;
+ /* the number of unprocessed bytes remaining in each message */
+ size_t unprocessed;
+
+ enum spacemit_i2c_state state;
+ enum spacemit_i2c_dir dir;
+ struct completion complete;
+ u32 status;
+ u32 err;
+};
+
+static int spacemit_i2c_handle_err(struct spacemit_i2c_dev *i2c);
+
+static inline u32 spacemit_i2c_read_reg(struct spacemit_i2c_dev *i2c, int reg)
+{
+ return readl(i2c->base + reg);
+}
+
+static inline void
+spacemit_i2c_write_reg(struct spacemit_i2c_dev *i2c, int reg, u32 val)
+{
+ writel(val, i2c->base + reg);
+}
+
+static void spacemit_i2c_enable(struct spacemit_i2c_dev *i2c)
+{
+ u32 val;
+
+ val = spacemit_i2c_read_reg(i2c, ICR);
+ spacemit_i2c_write_reg(i2c, ICR, val | CR_IUE);
+}
+
+static void spacemit_i2c_disable(struct spacemit_i2c_dev *i2c)
+{
+ u32 val;
+
+ val = spacemit_i2c_read_reg(i2c, ICR);
+ val &= ~CR_IUE;
+ spacemit_i2c_write_reg(i2c, ICR, val);
+}
+
+static void spacemit_i2c_reset(struct spacemit_i2c_dev *i2c)
+{
+ spacemit_i2c_write_reg(i2c, ICR, CR_UR);
+ udelay(5);
+ spacemit_i2c_write_reg(i2c, ICR, 0);
+}
+
+static void spacemit_i2c_bus_reset(struct spacemit_i2c_dev *i2c)
+{
+ u32 status;
+
+ /* if bus is locked, reset unit. 0: locked */
+ status = spacemit_i2c_read_reg(i2c, IBMR);
+
+ if ((status & BMR_SDA) && (status & BMR_SCL))
+ return;
+
+ spacemit_i2c_reset(i2c);
+ usleep_range(10, 20);
+
+ /* check scl status again */
+ status = spacemit_i2c_read_reg(i2c, IBMR);
+
+ if (!(status & BMR_SCL))
+ dev_alert(i2c->dev, "unit reset failed\n");
+}
+
+static int spacemit_i2c_recover_bus_busy(struct spacemit_i2c_dev *i2c)
+{
+ int ret = 0;
+ u32 val;
+
+ val = spacemit_i2c_read_reg(i2c, ISR);
+
+ if (likely(!(val & (SR_UB | SR_IBB))))
+ return 0;
+
+ ret = readl_poll_timeout(i2c->base + ISR,
+ val,
+ !(val & (SR_UB | SR_IBB)),
+ 1500,
+ I2C_BUS_RECOVER_TIMEOUT);
+
+ if (unlikely(ret)) {
+ spacemit_i2c_reset(i2c);
+ ret = -EAGAIN;
+ }
+
+ return ret;
+}
+
+static void spacemit_i2c_check_bus_release(struct spacemit_i2c_dev *i2c)
+{
+ /* in case bus is not released after transfer completes */
+ if (unlikely(spacemit_i2c_read_reg(i2c, ISR) & SR_EBB)) {
+ spacemit_i2c_bus_reset(i2c);
+ usleep_range(90, 150);
+ }
+}
+
+static void spacemit_i2c_init(struct spacemit_i2c_dev *i2c)
+{
+ u32 val = 0;
+
+ /*
+ * Unmask interrupt bits for all xfer mode:
+ * bus error, arbitration loss detected.
+ * For transaction complete signal, we use master stop
+ * interrupt, so we don't need to unmask CR_TXDONEIE.
+ */
+ val |= CR_BEIE | CR_ALDIE;
+
+ /*
+ * Unmask interrupt bits for interrupt xfer mode:
+ * DBR rx full.
+ * For tx empty interrupt CR_DTEIE, we only
+ * need to enable when trigger byte transfer to start
+ * data sending.
+ */
+ val |= CR_DRFIE;
+
+ /* set speed bits: default fast mode */
+ val |= CR_MODE_FAST;
+
+ /* disable response to general call */
+ val |= CR_GCD;
+
+ /* enable SCL clock output */
+ val |= CR_SCLE;
+
+ /* enable master stop detected */
+ val |= CR_MSDE | CR_MSDIE;
+
+ spacemit_i2c_write_reg(i2c, ICR, val);
+}
+
+static inline void
+spacemit_i2c_clear_int_status(struct spacemit_i2c_dev *i2c, u32 mask)
+{
+ spacemit_i2c_write_reg(i2c, ISR, mask & I2C_INT_STATUS_MASK);
+}
+
+static void spacemit_i2c_start(struct spacemit_i2c_dev *i2c)
+{
+ u32 slave_addr_rw, val;
+
+ i2c->dir = i2c->cur_msg->flags & I2C_M_RD;
+ i2c->state = STATE_START;
+
+ if (i2c->cur_msg->flags & I2C_M_RD)
+ slave_addr_rw = ((i2c->cur_msg->addr & 0x7f) << 1) | 1;
+ else
+ slave_addr_rw = (i2c->cur_msg->addr & 0x7f) << 1;
+
+ spacemit_i2c_write_reg(i2c, IDBR, slave_addr_rw);
+
+ val = spacemit_i2c_read_reg(i2c, ICR);
+
+ /* send start pulse */
+ val &= ~CR_STOP;
+ val |= CR_START | CR_TB | CR_DTEIE;
+ spacemit_i2c_write_reg(i2c, ICR, val);
+}
+
+static void spacemit_i2c_stop(struct spacemit_i2c_dev *i2c)
+{
+ u32 val;
+
+ val = spacemit_i2c_read_reg(i2c, ICR);
+
+ val |= CR_STOP | CR_ALDIE | CR_TB;
+
+ if (i2c->dir == DIR_READ)
+ val |= CR_ACKNAK;
+
+ spacemit_i2c_write_reg(i2c, ICR, val);
+}
+
+static int spacemit_i2c_xfer_msg(struct spacemit_i2c_dev *i2c)
+{
+ unsigned long time_left;
+
+ if (unlikely(i2c->err))
+ return -1;
+
+ for (i2c->msg_idx = 0; i2c->msg_idx < i2c->msg_num; i2c->msg_idx++) {
+ i2c->cur_msg = i2c->msgs + i2c->msg_idx;
+ i2c->msg_buf = i2c->cur_msg->buf;
+ i2c->err = 0;
+ i2c->status = 0;
+ i2c->unprocessed = i2c->cur_msg->len;
+
+ reinit_completion(&i2c->complete);
+
+ spacemit_i2c_start(i2c);
+
+ time_left = wait_for_completion_timeout(&i2c->complete,
+ i2c->adapt.timeout);
+
+ if (unlikely(time_left == 0)) {
+ dev_alert(i2c->dev, "msg completion timeout\n");
+ spacemit_i2c_bus_reset(i2c);
+ spacemit_i2c_reset(i2c);
+ return -ETIMEDOUT;
+ }
+
+ if (unlikely(i2c->err))
+ return spacemit_i2c_handle_err(i2c);
+ }
+
+ return 0;
+}
+
+static int spacemit_i2c_is_last_msg(struct spacemit_i2c_dev *i2c)
+{
+ if (i2c->dir == DIR_READ) {
+ if (i2c->unprocessed == 1 && i2c->msg_idx == i2c->msg_num - 1)
+ return 1;
+ return 0;
+ } else if (i2c->dir == DIR_WRITE) {
+ if (!i2c->unprocessed && i2c->msg_idx == i2c->msg_num - 1)
+ return 1;
+ return 0;
+ }
+ return 0;
+}
+
+static void spacemit_i2c_handle_write(struct spacemit_i2c_dev *i2c)
+{
+ /* if transfer completes, ISR will handle it */
+ if (i2c->status & SR_MSD)
+ return;
+
+ if (i2c->unprocessed) {
+ spacemit_i2c_write_reg(i2c, IDBR, *i2c->msg_buf++);
+ i2c->unprocessed--;
+ return;
+ }
+
+ /* STATE_IDLE avoids trigger next byte */
+ i2c->state = STATE_IDLE;
+ complete(&i2c->complete);
+}
+
+static void spacemit_i2c_handle_read(struct spacemit_i2c_dev *i2c)
+{
+ if (i2c->unprocessed) {
+ *i2c->msg_buf++ = spacemit_i2c_read_reg(i2c, IDBR);
+ i2c->unprocessed--;
+ }
+
+ /* if transfer completes, ISR will handle it */
+ if (i2c->status & (SR_MSD | SR_ACKNAK))
+ return;
+
+ /* it has to append stop bit in icr that read last byte */
+ if (i2c->unprocessed)
+ return;
+
+ /* STATE_IDLE avoids trigger next byte */
+ i2c->state = STATE_IDLE;
+ complete(&i2c->complete);
+}
+
+static void spacemit_i2c_handle_start(struct spacemit_i2c_dev *i2c)
+{
+ if (i2c->dir == DIR_READ) {
+ i2c->state = STATE_READ;
+ return;
+ }
+
+ if (i2c->dir == DIR_WRITE) {
+ i2c->state = STATE_WRITE;
+ spacemit_i2c_handle_write(i2c);
+ }
+}
+
+static int spacemit_i2c_handle_err(struct spacemit_i2c_dev *i2c)
+{
+ if (!i2c->err)
+ return 0;
+
+ dev_dbg(i2c->dev, "i2c error status: 0x%08x\n", i2c->status);
+
+ if (i2c->err & (SR_BED | SR_ALD))
+ spacemit_i2c_reset(i2c);
+
+ if (i2c->err & (SR_RXOV | SR_ALD))
+ return -EAGAIN;
+
+ return (i2c->status & SR_ACKNAK) ? -ENXIO : -EIO;
+}
+
+static void spacemit_i2c_err_check(struct spacemit_i2c_dev *i2c)
+{
+ u32 val;
+ /*
+ * send transaction complete signal:
+ * error happens, detect master stop
+ */
+ if (likely(i2c->err || (i2c->status & SR_MSD))) {
+ /*
+ * Here the transaction is already done, we don't need any
+ * other interrupt signals from now, in case any interrupt
+ * happens before spacemit_i2c_xfer to disable irq and i2c unit,
+ * we mask all the interrupt signals and clear the interrupt
+ * status.
+ */
+ val = spacemit_i2c_read_reg(i2c, ICR);
+ val &= ~I2C_INT_CTRL_MASK;
+ spacemit_i2c_write_reg(i2c, ICR, val);
+
+ spacemit_i2c_clear_int_status(i2c, I2C_INT_STATUS_MASK);
+
+ i2c->state = STATE_IDLE;
+ complete(&i2c->complete);
+ }
+}
+
+static irqreturn_t spacemit_i2c_irq_handler(int irq, void *devid)
+{
+ struct spacemit_i2c_dev *i2c = devid;
+ u32 status, val;
+
+ status = spacemit_i2c_read_reg(i2c, ISR);
+
+ if (!status)
+ return IRQ_HANDLED;
+
+ i2c->status = status;
+
+ i2c->err = status & (SR_BED | SR_RXOV | SR_ALD);
+
+ spacemit_i2c_clear_int_status(i2c, status);
+
+ if (unlikely(i2c->err))
+ goto err_out;
+
+ val = spacemit_i2c_read_reg(i2c, ICR);
+
+ val &= ~(CR_TB | CR_ACKNAK | CR_STOP | CR_START);
+ spacemit_i2c_write_reg(i2c, ICR, val);
+
+ switch (i2c->state) {
+ case STATE_START:
+ spacemit_i2c_handle_start(i2c);
+ break;
+ case STATE_READ:
+ spacemit_i2c_handle_read(i2c);
+ break;
+ case STATE_WRITE:
+ spacemit_i2c_handle_write(i2c);
+ break;
+ default:
+ break;
+ }
+
+ if (i2c->state != STATE_IDLE) {
+ if (spacemit_i2c_is_last_msg(i2c)) {
+ /* trigger next byte with stop */
+ spacemit_i2c_stop(i2c);
+ } else {
+ /* trigger next byte */
+ val |= CR_ALDIE | CR_TB;
+ spacemit_i2c_write_reg(i2c, ICR, val);
+ }
+ }
+
+err_out:
+ spacemit_i2c_err_check(i2c);
+ return IRQ_HANDLED;
+}
+
+static void spacemit_i2c_calc_timeout(struct spacemit_i2c_dev *i2c)
+{
+ unsigned long timeout;
+ int idx = 0, cnt = 0, freq;
+
+ while (idx < i2c->msg_num) {
+ cnt += (i2c->msgs + idx)->len + 1;
+
+ idx++;
+ }
+
+ freq = I2C_FAST_MODE_FREQ;
+
+ timeout = cnt * 9 * USEC_PER_SEC / freq;
+
+ i2c->adapt.timeout = usecs_to_jiffies(timeout + USEC_PER_SEC / 2) / i2c->msg_num;
+}
+
+static inline int spacemit_i2c_xfer_core(struct spacemit_i2c_dev *i2c)
+{
+ int ret = 0;
+
+ spacemit_i2c_reset(i2c);
+
+ spacemit_i2c_calc_timeout(i2c);
+
+ spacemit_i2c_init(i2c);
+
+ spacemit_i2c_enable(i2c);
+ enable_irq(i2c->irq);
+
+ /* i2c wait for bus busy */
+ ret = spacemit_i2c_recover_bus_busy(i2c);
+
+ if (unlikely(ret))
+ return ret;
+
+ ret = spacemit_i2c_xfer_msg(i2c);
+
+ if (unlikely(ret < 0)) {
+ dev_dbg(i2c->dev, "i2c transfer error\n");
+ /* timeout error should not be overridden, and the transfer
+ * error will be confirmed by err handle function latter,
+ * the reset should be invalid argument error.
+ */
+ if (ret != -ETIMEDOUT)
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
+static int
+spacemit_i2c_xfer(struct i2c_adapter *adapt, struct i2c_msg msgs[], int num)
+{
+ struct spacemit_i2c_dev *i2c = i2c_get_adapdata(adapt);
+ int ret;
+
+ i2c->msgs = msgs;
+ i2c->msg_num = num;
+
+ ret = spacemit_i2c_xfer_core(i2c);
+
+ if (likely(!ret))
+ spacemit_i2c_check_bus_release(i2c);
+
+ disable_irq(i2c->irq);
+
+ spacemit_i2c_disable(i2c);
+
+ if (unlikely((ret == -ETIMEDOUT || ret == -EAGAIN)))
+ dev_alert(i2c->dev, "i2c transfer failed, ret %d err 0x%x\n",
+ ret, i2c->err);
+
+ return ret < 0 ? ret : num;
+}
+
+static u32 spacemit_i2c_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+}
+
+static const struct i2c_algorithm spacemit_i2c_algo = {
+ .xfer = spacemit_i2c_xfer,
+ .functionality = spacemit_i2c_func,
+};
+
+static int spacemit_i2c_probe(struct platform_device *pdev)
+{
+ struct spacemit_i2c_dev *i2c;
+ struct device_node *of_node = pdev->dev.of_node;
+ struct clk *clk;
+ int ret = 0;
+
+ i2c = devm_kzalloc(&pdev->dev,
+ sizeof(struct spacemit_i2c_dev),
+ GFP_KERNEL);
+ if (!i2c)
+ return -ENOMEM;
+
+ i2c->dev = &pdev->dev;
+
+ i2c->base = devm_platform_ioremap_resource(pdev, 0);
+ if (!i2c->base) {
+ ret = PTR_ERR(i2c->base);
+ return dev_err_probe(&pdev->dev, ret, "failed to do ioremap");
+ }
+
+ i2c->irq = platform_get_irq(pdev, 0);
+ if (i2c->irq < 0) {
+ ret = i2c->irq;
+ return dev_err_probe(&pdev->dev, ret, "failed to get irq resource");
+ }
+
+ ret = devm_request_irq(i2c->dev, i2c->irq,
+ spacemit_i2c_irq_handler,
+ IRQF_NO_SUSPEND | IRQF_ONESHOT,
+ dev_name(i2c->dev), i2c);
+
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret, "failed to request irq");
+
+ disable_irq(i2c->irq);
+
+ clk = devm_clk_get_enabled(&pdev->dev, NULL);
+ if (IS_ERR(clk)) {
+ ret = PTR_ERR(clk);
+ return dev_err_probe(&pdev->dev, ret, "failed to enable clock");
+ }
+
+ i2c_set_adapdata(&i2c->adapt, i2c);
+ i2c->adapt.owner = THIS_MODULE;
+ i2c->adapt.algo = &spacemit_i2c_algo;
+ i2c->adapt.dev.parent = i2c->dev;
+ i2c->adapt.nr = pdev->id;
+
+ i2c->adapt.dev.of_node = of_node;
+ i2c->adapt.algo_data = i2c;
+
+ strscpy(i2c->adapt.name, "spacemit-i2c-adapter", sizeof(i2c->adapt.name));
+
+ init_completion(&i2c->complete);
+
+ ret = i2c_add_numbered_adapter(&i2c->adapt);
+
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret, "failed to add i2c adapter");
+
+ platform_set_drvdata(pdev, i2c);
+
+ return 0;
+}
+
+static void spacemit_i2c_remove(struct platform_device *pdev)
+{
+ struct spacemit_i2c_dev *i2c = platform_get_drvdata(pdev);
+
+ i2c_del_adapter(&i2c->adapt);
+}
+
+static const struct of_device_id spacemit_i2c_dt_match[] = {
+ { .compatible = "spacemit,k1-i2c", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, spacemit_i2c_dt_match);
+
+static struct platform_driver spacemit_i2c_driver = {
+ .probe = spacemit_i2c_probe,
+ .remove_new = spacemit_i2c_remove,
+ .driver = {
+ .name = "i2c-k1",
+ .of_match_table = spacemit_i2c_dt_match,
+ },
+};
+module_platform_driver(spacemit_i2c_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("I2C bus driver for SpacemiT K1 SoC");
--
2.34.1
