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Wed, 19 Mar 2025 02:32:11 -0700 (PDT) Received: from [127.0.1.1] ([2602:f919:106::1b8]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-737115294b3sm11124315b3a.5.2025.03.19.02.32.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Mar 2025 02:32:10 -0700 (PDT) From: Troy Mitchell Date: Wed, 19 Mar 2025 17:29:00 +0800 Subject: [PATCH v8 2/2] i2c: spacemit: add support for SpacemiT K1 SoC Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250319-k1-i2c-master-v8-2-013e2df2b78d@gmail.com> References: <20250319-k1-i2c-master-v8-0-013e2df2b78d@gmail.com> In-Reply-To: <20250319-k1-i2c-master-v8-0-013e2df2b78d@gmail.com> To: Andi Shyti , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Yixun Lan , Troy Mitchell Cc: linux-riscv@lists.infradead.org, linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, spacemit@lists.linux.dev, Alex Elder X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1742376553; l=20934; i=troymitchell988@gmail.com; h=from:subject:message-id; bh=Aw5Q41DMxVInbZQtazTI8t8nnM69KV0jbw0/R6eJL6w=; b=XwQUgUwkFeWokQcQMCCP1Knbm4E06LuQUA3ZILzTZJ0X/xgdOSHU0es2V7/ifaeC9C4fg9fDU j4n7RQE0nv7CCXxV/B+6/I1VWD/Ybq1O7QCqPddvr4tn04BDbezjXid X-Developer-Key: i=troymitchell988@gmail.com; a=ed25519; pk=2spEMGBd/Wkpd36N1aD9KFWOk0aHrhVxZQt+jxLXVC0= 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. Reviewed-by: Alex Elder Link: https://lore.kernel.org/all/20250128-k1-maintainer-1-v1-1-e5dec4f379eb@gentoo.org [1] Signed-off-by: Troy Mitchell --- drivers/i2c/busses/Kconfig | 17 ++ drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-k1.c | 602 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 620 insertions(+) diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index fc438f4457713d5559d163840a7b11e8cdbb8f58..41dd05644c43a8630a6d53f70ec7fbf899d297b5 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -783,6 +783,23 @@ config I2C_JZ4780 If you don't know what to do here, say N. +config I2C_K1 + tristate "SpacemiT K1 I2C adapter" + depends on ARCH_SPACEMIT || COMPILE_TEST + depends on OF + 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 can + 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 built as a module. If so, the + module will be called `i2c-k1`. + config I2C_KEBA tristate "KEBA I2C controller support" depends on HAS_IOMEM diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 1c2a4510abe44a689dfe67d2d64cf0cf3434f510..c1252e2b779e2e47492d66179b442f2202ec0416 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -74,6 +74,7 @@ obj-$(CONFIG_I2C_IMX) += i2c-imx.o obj-$(CONFIG_I2C_IMX_LPI2C) += i2c-imx-lpi2c.o obj-$(CONFIG_I2C_IOP3XX) += i2c-iop3xx.o obj-$(CONFIG_I2C_JZ4780) += i2c-jz4780.o +obj-$(CONFIG_I2C_K1) += i2c-k1.o obj-$(CONFIG_I2C_KEBA) += i2c-keba.o obj-$(CONFIG_I2C_KEMPLD) += i2c-kempld.o obj-$(CONFIG_I2C_LPC2K) += i2c-lpc2k.o diff --git a/drivers/i2c/busses/i2c-k1.c b/drivers/i2c/busses/i2c-k1.c new file mode 100644 index 0000000000000000000000000000000000000000..0d8763b852db9829c6d5adc0ee99c1f3d8176290 --- /dev/null +++ b/drivers/i2c/busses/i2c-k1.c @@ -0,0 +1,602 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2024-2025 Troy Mitchell + */ + + #include + #include + #include + #include + #include + #include + +/* spacemit i2c registers */ +#define SPACEMIT_ICR 0x0 /* Control register */ +#define SPACEMIT_ISR 0x4 /* Status register */ +#define SPACEMIT_IDBR 0xc /* Data buffer register */ +#define SPACEMIT_IBMR 0x1c /* Bus monitor register */ + +/* SPACEMIT_ICR register fields */ +#define SPACEMIT_CR_START BIT(0) /* start bit */ +#define SPACEMIT_CR_STOP BIT(1) /* stop bit */ +#define SPACEMIT_CR_ACKNAK BIT(2) /* send ACK(0) or NAK(1) */ +#define SPACEMIT_CR_TB BIT(3) /* transfer byte bit */ +/* Bits 4-7 are reserved */ +#define SPACEMIT_CR_MODE_FAST BIT(8) /* bus mode (master operation) */ +/* Bit 9 is reserved */ +#define SPACEMIT_CR_UR BIT(10) /* unit reset */ +/* Bits 11-12 are reserved */ +#define SPACEMIT_CR_SCLE BIT(13) /* master clock enable */ +#define SPACEMIT_CR_IUE BIT(14) /* unit enable */ +/* Bits 15-17 are reserved */ +#define SPACEMIT_CR_ALDIE BIT(18) /* enable arbitration interrupt */ +#define SPACEMIT_CR_DTEIE BIT(19) /* enable TX interrupts */ +#define SPACEMIT_CR_DRFIE BIT(20) /* enable RX interrupts */ +#define SPACEMIT_CR_GCD BIT(21) /* general call disable */ +#define SPACEMIT_CR_BEIE BIT(22) /* enable bus error ints */ +/* Bits 23-24 are reserved */ +#define SPACEMIT_CR_MSDIE BIT(25) /* master STOP detected int enable */ +#define SPACEMIT_CR_MSDE BIT(26) /* master STOP detected enable */ +#define SPACEMIT_CR_TXDONEIE BIT(27) /* transaction done int enable */ +#define SPACEMIT_CR_TXEIE BIT(28) /* transmit FIFO empty int enable */ +#define SPACEMIT_CR_RXHFIE BIT(29) /* receive FIFO half-full int enable */ +#define SPACEMIT_CR_RXFIE BIT(30) /* receive FIFO full int enable */ +#define SPACEMIT_CR_RXOVIE BIT(31) /* receive FIFO overrun int enable */ + +#define SPACEMIT_I2C_INT_CTRL_MASK (SPACEMIT_CR_ALDIE | SPACEMIT_CR_DTEIE | \ + SPACEMIT_CR_DRFIE | SPACEMIT_CR_BEIE | \ + SPACEMIT_CR_TXDONEIE | SPACEMIT_CR_TXEIE | \ + SPACEMIT_CR_RXHFIE | SPACEMIT_CR_RXFIE | \ + SPACEMIT_CR_RXOVIE | SPACEMIT_CR_MSDIE) + +/* SPACEMIT_ISR register fields */ +/* Bits 0-13 are reserved */ +#define SPACEMIT_SR_ACKNAK BIT(14) /* ACK/NACK status */ +#define SPACEMIT_SR_UB BIT(15) /* unit busy */ +#define SPACEMIT_SR_IBB BIT(16) /* i2c bus busy */ +#define SPACEMIT_SR_EBB BIT(17) /* early bus busy */ +#define SPACEMIT_SR_ALD BIT(18) /* arbitration loss detected */ +#define SPACEMIT_SR_ITE BIT(19) /* TX buffer empty */ +#define SPACEMIT_SR_IRF BIT(20) /* RX buffer full */ +#define SPACEMIT_SR_GCAD BIT(21) /* general call address detected */ +#define SPACEMIT_SR_BED BIT(22) /* bus error no ACK/NAK */ +#define SPACEMIT_SR_SAD BIT(23) /* slave address detected */ +#define SPACEMIT_SR_SSD BIT(24) /* slave stop detected */ +/* Bit 25 is reserved */ +#define SPACEMIT_SR_MSD BIT(26) /* master stop detected */ +#define SPACEMIT_SR_TXDONE BIT(27) /* transaction done */ +#define SPACEMIT_SR_TXE BIT(28) /* TX FIFO empty */ +#define SPACEMIT_SR_RXHF BIT(29) /* RX FIFO half-full */ +#define SPACEMIT_SR_RXF BIT(30) /* RX FIFO full */ +#define SPACEMIT_SR_RXOV BIT(31) /* RX FIFO overrun */ + +#define SPACEMIT_I2C_INT_STATUS_MASK (SPACEMIT_SR_RXOV | SPACEMIT_SR_RXF | SPACEMIT_SR_RXHF | \ + SPACEMIT_SR_TXE | SPACEMIT_SR_TXDONE | SPACEMIT_SR_MSD | \ + SPACEMIT_SR_SSD | SPACEMIT_SR_SAD | SPACEMIT_SR_BED | \ + SPACEMIT_SR_GCAD | SPACEMIT_SR_IRF | SPACEMIT_SR_ITE | \ + SPACEMIT_SR_ALD) + +/* SPACEMIT_IBMR register fields */ +#define SPACEMIT_BMR_SDA BIT(0) /* SDA line level */ +#define SPACEMIT_BMR_SCL BIT(1) /* SCL line level */ + +/* i2c bus recover timeout: us */ +#define SPACEMIT_I2C_BUS_BUSY_TIMEOUT 100000 + +#define SPACEMIT_I2C_MAX_STANDARD_MODE_FREQ 100000 /* Hz */ +#define SPACEMIT_I2C_MAX_FAST_MODE_FREQ 400000 /* Hz */ + +#define SPACEMIT_SR_ERR (SPACEMIT_SR_BED | SPACEMIT_SR_RXOV | SPACEMIT_SR_ALD) + +enum spacemit_i2c_state { + SPACEMIT_STATE_IDLE, + SPACEMIT_STATE_START, + SPACEMIT_STATE_READ, + SPACEMIT_STATE_WRITE, +}; + +/* i2c-spacemit driver's main struct */ +struct spacemit_i2c_dev { + struct device *dev; + struct i2c_adapter adapt; + + /* hardware resources */ + void __iomem *base; + int irq; + u32 clock_freq; + + struct i2c_msg *msgs; + u32 msg_num; + + /* index of the current message being processed */ + u32 msg_idx; + u8 *msg_buf; + /* the number of unprocessed bytes remaining in the current message */ + u32 unprocessed; + + enum spacemit_i2c_state state; + bool read; + struct completion complete; + u32 status; +}; + +static void spacemit_i2c_enable(struct spacemit_i2c_dev *i2c) +{ + u32 val; + + val = readl(i2c->base + SPACEMIT_ICR); + val |= SPACEMIT_CR_IUE; + writel(val, i2c->base + SPACEMIT_ICR); +} + +static void spacemit_i2c_disable(struct spacemit_i2c_dev *i2c) +{ + u32 val; + + val = readl(i2c->base + SPACEMIT_ICR); + val &= ~SPACEMIT_CR_IUE; + writel(val, i2c->base + SPACEMIT_ICR); +} + +static void spacemit_i2c_reset(struct spacemit_i2c_dev *i2c) +{ + writel(SPACEMIT_CR_UR, i2c->base + SPACEMIT_ICR); + udelay(5); + writel(0, i2c->base + SPACEMIT_ICR); +} + +static int spacemit_i2c_handle_err(struct spacemit_i2c_dev *i2c) +{ + dev_dbg(i2c->dev, "i2c error status: 0x%08x\n", i2c->status); + + if (i2c->status & (SPACEMIT_SR_BED | SPACEMIT_SR_ALD)) { + spacemit_i2c_reset(i2c); + return -EAGAIN; + } + + return i2c->status & SPACEMIT_SR_ACKNAK ? -ENXIO : -EIO; +} + +static void spacemit_i2c_conditionally_reset_bus(struct spacemit_i2c_dev *i2c) +{ + u32 status; + + /* if bus is locked, reset unit. 0: locked */ + status = readl(i2c->base + SPACEMIT_IBMR); + if ((status & SPACEMIT_BMR_SDA) && (status & SPACEMIT_BMR_SCL)) + return; + + spacemit_i2c_reset(i2c); + usleep_range(10, 20); + + /* check scl status again */ + status = readl(i2c->base + SPACEMIT_IBMR); + if (!(status & SPACEMIT_BMR_SCL)) + dev_warn_ratelimited(i2c->dev, "unit reset failed\n"); +} + +static int spacemit_i2c_wait_bus_idle(struct spacemit_i2c_dev *i2c) +{ + int ret; + u32 val; + + val = readl(i2c->base + SPACEMIT_ISR); + if (!(val & (SPACEMIT_SR_UB | SPACEMIT_SR_IBB))) + return 0; + + ret = readl_poll_timeout(i2c->base + SPACEMIT_ISR, + val, !(val & (SPACEMIT_SR_UB | SPACEMIT_SR_IBB)), + 1500, SPACEMIT_I2C_BUS_BUSY_TIMEOUT); + if (ret) + spacemit_i2c_reset(i2c); + + return ret; +} + +static void spacemit_i2c_check_bus_release(struct spacemit_i2c_dev *i2c) +{ + /* in case bus is not released after transfer completes */ + if (readl(i2c->base + SPACEMIT_ISR) & SPACEMIT_SR_EBB) { + spacemit_i2c_conditionally_reset_bus(i2c); + usleep_range(90, 150); + } +} + +static void spacemit_i2c_init(struct spacemit_i2c_dev *i2c) +{ + u32 val; + + /* + * 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 SPACEMIT_CR_TXDONEIE. + */ + val = SPACEMIT_CR_BEIE | SPACEMIT_CR_ALDIE; + + /* + * Unmask interrupt bits for interrupt xfer mode: + * When IDBR receives a byte, an interrupt is triggered. + * + * For the tx empty interrupt, it will be enabled in the + * i2c_start function. + * Otherwise, it will cause an erroneous empty interrupt before i2c_start. + */ + val |= SPACEMIT_CR_DRFIE; + + if (i2c->clock_freq == SPACEMIT_I2C_MAX_FAST_MODE_FREQ) + val |= SPACEMIT_CR_MODE_FAST; + + /* disable response to general call */ + val |= SPACEMIT_CR_GCD; + + /* enable SCL clock output */ + val |= SPACEMIT_CR_SCLE; + + /* enable master stop detected */ + val |= SPACEMIT_CR_MSDE | SPACEMIT_CR_MSDIE; + + writel(val, i2c->base + SPACEMIT_ICR); +} + +static inline void +spacemit_i2c_clear_int_status(struct spacemit_i2c_dev *i2c, u32 mask) +{ + writel(mask & SPACEMIT_I2C_INT_STATUS_MASK, i2c->base + SPACEMIT_ISR); +} + +static void spacemit_i2c_start(struct spacemit_i2c_dev *i2c) +{ + u32 target_addr_rw, val; + struct i2c_msg *cur_msg = i2c->msgs + i2c->msg_idx; + + i2c->read = !!(cur_msg->flags & I2C_M_RD); + + i2c->state = SPACEMIT_STATE_START; + + target_addr_rw = (cur_msg->addr & 0x7f) << 1; + if (cur_msg->flags & I2C_M_RD) + target_addr_rw |= 1; + + writel(target_addr_rw, i2c->base + SPACEMIT_IDBR); + + /* send start pulse */ + val = readl(i2c->base + SPACEMIT_ICR); + val &= ~SPACEMIT_CR_STOP; + val |= SPACEMIT_CR_START | SPACEMIT_CR_TB | SPACEMIT_CR_DTEIE; + writel(val, i2c->base + SPACEMIT_ICR); +} + +static void spacemit_i2c_stop(struct spacemit_i2c_dev *i2c) +{ + u32 val; + + val = readl(i2c->base + SPACEMIT_ICR); + val |= SPACEMIT_CR_STOP | SPACEMIT_CR_ALDIE | SPACEMIT_CR_TB; + + if (i2c->read) + val |= SPACEMIT_CR_ACKNAK; + + writel(val, i2c->base + SPACEMIT_ICR); +} + +static int spacemit_i2c_xfer_msg(struct spacemit_i2c_dev *i2c) +{ + unsigned long time_left; + struct i2c_msg *msg; + + for (i2c->msg_idx = 0; i2c->msg_idx < i2c->msg_num; i2c->msg_idx++) { + msg = &i2c->msgs[i2c->msg_idx]; + i2c->msg_buf = msg->buf; + i2c->unprocessed = msg->len; + i2c->status = 0; + + reinit_completion(&i2c->complete); + + spacemit_i2c_start(i2c); + + time_left = wait_for_completion_timeout(&i2c->complete, + i2c->adapt.timeout); + if (!time_left) { + dev_err(i2c->dev, "msg completion timeout\n"); + spacemit_i2c_conditionally_reset_bus(i2c); + spacemit_i2c_reset(i2c); + return -ETIMEDOUT; + } + + if (i2c->status & SPACEMIT_SR_ERR) + return spacemit_i2c_handle_err(i2c); + } + + return 0; +} + +static bool spacemit_i2c_is_last_msg(struct spacemit_i2c_dev *i2c) +{ + if (i2c->msg_idx != i2c->msg_num - 1) + return false; + + if (i2c->read) + return i2c->unprocessed == 1; + + return !i2c->unprocessed; +} + +static void spacemit_i2c_handle_write(struct spacemit_i2c_dev *i2c) +{ + /* if transfer completes, SPACEMIT_ISR will handle it */ + if (i2c->status & SPACEMIT_SR_MSD) + return; + + if (i2c->unprocessed) { + writel(*i2c->msg_buf++, i2c->base + SPACEMIT_IDBR); + i2c->unprocessed--; + return; + } + + /* SPACEMIT_STATE_IDLE avoids trigger next byte */ + i2c->state = SPACEMIT_STATE_IDLE; + complete(&i2c->complete); +} + +static void spacemit_i2c_handle_read(struct spacemit_i2c_dev *i2c) +{ + if (i2c->unprocessed) { + *i2c->msg_buf++ = readl(i2c->base + SPACEMIT_IDBR); + i2c->unprocessed--; + } + + /* if transfer completes, SPACEMIT_ISR will handle it */ + if (i2c->status & (SPACEMIT_SR_MSD | SPACEMIT_SR_ACKNAK)) + return; + + /* it has to append stop bit in icr that read last byte */ + if (i2c->unprocessed) + return; + + /* SPACEMIT_STATE_IDLE avoids trigger next byte */ + i2c->state = SPACEMIT_STATE_IDLE; + complete(&i2c->complete); +} + +static void spacemit_i2c_handle_start(struct spacemit_i2c_dev *i2c) +{ + i2c->state = i2c->read ? SPACEMIT_STATE_READ : SPACEMIT_STATE_WRITE; + if (i2c->state == SPACEMIT_STATE_WRITE) + spacemit_i2c_handle_write(i2c); +} + +static void spacemit_i2c_err_check(struct spacemit_i2c_dev *i2c) +{ + u32 val; + + /* + * Send transaction complete signal: + * error happens, detect master stop + */ + if (!(i2c->status & (SPACEMIT_SR_ERR | SPACEMIT_SR_MSD))) + return; + + /* + * 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 = readl(i2c->base + SPACEMIT_ICR); + val &= ~SPACEMIT_I2C_INT_CTRL_MASK; + writel(val, i2c->base + SPACEMIT_ICR); + + spacemit_i2c_clear_int_status(i2c, SPACEMIT_I2C_INT_STATUS_MASK); + + i2c->state = SPACEMIT_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 = readl(i2c->base + SPACEMIT_ISR); + if (!status) + return IRQ_HANDLED; + + i2c->status = status; + + spacemit_i2c_clear_int_status(i2c, status); + + if (i2c->status & SPACEMIT_SR_ERR) + goto err_out; + + val = readl(i2c->base + SPACEMIT_ICR); + val &= ~(SPACEMIT_CR_TB | SPACEMIT_CR_ACKNAK | SPACEMIT_CR_STOP | SPACEMIT_CR_START); + writel(val, i2c->base + SPACEMIT_ICR); + + switch (i2c->state) { + case SPACEMIT_STATE_START: + spacemit_i2c_handle_start(i2c); + break; + case SPACEMIT_STATE_READ: + spacemit_i2c_handle_read(i2c); + break; + case SPACEMIT_STATE_WRITE: + spacemit_i2c_handle_write(i2c); + break; + default: + break; + } + + if (i2c->state != SPACEMIT_STATE_IDLE) { + if (spacemit_i2c_is_last_msg(i2c)) { + /* trigger next byte with stop */ + spacemit_i2c_stop(i2c); + } else { + /* trigger next byte */ + val |= SPACEMIT_CR_ALDIE | SPACEMIT_CR_TB; + writel(val, i2c->base + SPACEMIT_ICR); + } + } + +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; + + for (; idx < i2c->msg_num; idx++) + cnt += (i2c->msgs + idx)->len + 1; + + /* + * Multiply by 9 because each byte in I2C transmission requires + * 9 clock cycles: 8 bits of data plus 1 ACK/NACK bit. + */ + timeout = cnt * 9 * USEC_PER_SEC / i2c->clock_freq; + + i2c->adapt.timeout = usecs_to_jiffies(timeout + USEC_PER_SEC / 10) / i2c->msg_num; +} + +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; + + spacemit_i2c_calc_timeout(i2c); + + spacemit_i2c_init(i2c); + + spacemit_i2c_enable(i2c); + + ret = spacemit_i2c_wait_bus_idle(i2c); + if (!ret) + spacemit_i2c_xfer_msg(i2c); + else if (ret < 0) + dev_dbg(i2c->dev, "i2c transfer error: %d\n", ret); + else + spacemit_i2c_check_bus_release(i2c); + + spacemit_i2c_disable(i2c); + + if (ret == -ETIMEDOUT || ret == -EAGAIN) + dev_err(i2c->dev, "i2c transfer failed, ret %d err 0x%lx\n", + ret, i2c->status & SPACEMIT_SR_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 clk *clk; + struct device *dev = &pdev->dev; + struct device_node *of_node = pdev->dev.of_node; + struct spacemit_i2c_dev *i2c; + int ret; + + i2c = devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL); + if (!i2c) + return -ENOMEM; + + of_property_read_u32(of_node, "clock-frequency", &i2c->clock_freq); + if (ret && ret != -EINVAL) + dev_warn(dev, "failed to read clock-frequency property: %d\n", ret); + + /* For now, this driver doesn't support high-speed. */ + if (!i2c->clock_freq || i2c->clock_freq > SPACEMIT_I2C_MAX_FAST_MODE_FREQ) { + dev_warn(dev, "unsupported clock frequency %u; using %u\n", + i2c->clock_freq, SPACEMIT_I2C_MAX_FAST_MODE_FREQ); + i2c->clock_freq = SPACEMIT_I2C_MAX_FAST_MODE_FREQ; + } else if (i2c->clock_freq < SPACEMIT_I2C_MAX_STANDARD_MODE_FREQ) { + dev_warn(dev, "unsupported clock frequency %u; using %u\n", + i2c->clock_freq, SPACEMIT_I2C_MAX_STANDARD_MODE_FREQ); + i2c->clock_freq = SPACEMIT_I2C_MAX_STANDARD_MODE_FREQ; + } + + i2c->dev = &pdev->dev; + + i2c->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(i2c->base)) + return dev_err_probe(dev, PTR_ERR(i2c->base), "failed to do ioremap"); + + i2c->irq = platform_get_irq(pdev, 0); + if (i2c->irq < 0) + return dev_err_probe(dev, i2c->irq, "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(dev, ret, "failed to request irq"); + + clk = devm_clk_get_enabled(dev, "func"); + if (IS_ERR(clk)) + return dev_err_probe(dev, PTR_ERR(clk), "failed to enable func clock"); + + clk = devm_clk_get_enabled(dev, "bus"); + if (IS_ERR(clk)) + return dev_err_probe(dev, PTR_ERR(clk), "failed to enable bus clock"); + + spacemit_i2c_reset(i2c); + + 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; + + strscpy(i2c->adapt.name, "spacemit-i2c-adapter", sizeof(i2c->adapt.name)); + + init_completion(&i2c->complete); + + platform_set_drvdata(pdev, i2c); + + ret = i2c_add_numbered_adapter(&i2c->adapt); + if (ret) + return dev_err_probe(&pdev->dev, ret, "failed to add i2c adapter"); + + 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_of_match[] = { + { .compatible = "spacemit,k1-i2c", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, spacemit_i2c_of_match); + +static struct platform_driver spacemit_i2c_driver = { + .probe = spacemit_i2c_probe, + .remove = spacemit_i2c_remove, + .driver = { + .name = "i2c-k1", + .of_match_table = spacemit_i2c_of_match, + }, +}; +module_platform_driver(spacemit_i2c_driver); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("I2C bus driver for SpacemiT K1 SoC");