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[60.250.196.139]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-367d65ed459sm13264489a91.14.2026.05.12.00.40.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 May 2026 00:40:09 -0700 (PDT) From: Zi-Yu Chen To: Jacky Huang , Andi Shyti Cc: Rob Herring , Krzysztof Kozlowski , Conor Dooley , linux-arm-kernel@lists.infradead.org, linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Zi-Yu Chen Subject: [PATCH v3 2/3] i2c: ma35d1: Add Nuvoton MA35D1 I2C driver support Date: Tue, 12 May 2026 15:39:52 +0800 Message-Id: <20260512073953.564323-3-zychennvt@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260512073953.564323-1-zychennvt@gmail.com> References: <20260512073953.564323-1-zychennvt@gmail.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add I2C support for Nuvoton MA35D1 SoC. The controller supports standard, fast and fast-plus modes, and provides controller/target functionality. Signed-off-by: Zi-Yu Chen --- drivers/i2c/busses/Kconfig | 13 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-ma35d1.c | 792 ++++++++++++++++++++++++++++++++ 3 files changed, 806 insertions(+) create mode 100644 drivers/i2c/busses/i2c-ma35d1.c diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index ea3e7e92465d..401dcc9be46b 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -1601,4 +1601,17 @@ config I2C_VIRTIO This driver can also be built as a module. If so, the module will be called i2c-virtio. +config I2C_MA35D1 + tristate "Nuvoton MA35D1 I2C driver" + depends on ARCH_MA35 || COMPILE_TEST + select I2C_SLAVE + help + If you say yes to this option, support will be included for the + I2C controller in the Nuvoton MA35D1 SoC. This driver + supports the standard I2C bus protocols, including master and + slave modes. + + This driver can also be built as a module. If so, the module + will be called i2c-ma35d1. + endmenu diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 3755c54b3d82..ca75dae4955c 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -131,6 +131,7 @@ 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 +obj-$(CONFIG_I2C_MA35D1) += i2c-ma35d1.o # External I2C/SMBus adapter drivers obj-$(CONFIG_I2C_DIOLAN_U2C) += i2c-diolan-u2c.o diff --git a/drivers/i2c/busses/i2c-ma35d1.c b/drivers/i2c/busses/i2c-ma35d1.c new file mode 100644 index 000000000000..c643f406e000 --- /dev/null +++ b/drivers/i2c/busses/i2c-ma35d1.c @@ -0,0 +1,792 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2026 Nuvoton technology corporation. + * + * Author: Zi-Yu Chen + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* MA35D1 I2C registers offset */ +#define MA35_CTL0 0x00 +#define MA35_ADDR0 0x04 +#define MA35_DAT 0x08 +#define MA35_STATUS0 0x0c +#define MA35_CLKDIV 0x10 +#define MA35_TOCTL 0x14 +#define MA35_ADDR1 0x18 +#define MA35_ADDR2 0x1c +#define MA35_ADDR3 0x20 +#define MA35_ADDRMSK0 0x24 +#define MA35_ADDRMSK1 0x28 +#define MA35_ADDRMSK2 0x2c +#define MA35_ADDRMSK3 0x30 +#define MA35_WKCTL 0x3c +#define MA35_WKSTS 0x40 +#define MA35_CTL1 0x44 +#define MA35_STATUS1 0x48 +#define MA35_TMCTL 0x4c +#define MA35_BUSCTL 0x50 +#define MA35_BUSTCTL 0x54 +#define MA35_BUSSTS 0x58 +#define MA35_PKTSIZE 0x5c +#define MA35_PKTCRC 0x60 +#define MA35_BUSTOUT 0x64 +#define MA35_CLKTOUT 0x68 +#define MA35_AUTOCNT 0x78 + +/* MA35D1 I2C Status */ +/* Controller */ +#define MA35_M_START 0x08 /* Start */ +#define MA35_M_REPEAT_START 0x10 /* Controller Repeat Start */ +#define MA35_M_TRAN_ADDR_ACK 0x18 /* Controller Transmit Address ACK */ +#define MA35_M_TRAN_ADDR_NACK 0x20 /* Controller Transmit Address NACK */ +#define MA35_M_TRAN_DATA_ACK 0x28 /* Controller Transmit Data ACK */ +#define MA35_M_TRAN_DATA_NACK 0x30 /* Controller Transmit Data NACK */ +#define MA35_M_ARB_LOST 0x38 /* Controller Arbitration Lost */ +#define MA35_M_RECE_ADDR_ACK 0x40 /* Controller Receive Address ACK */ +#define MA35_M_RECE_ADDR_NACK 0x48 /* Controller Receive Address NACK */ +#define MA35_M_RECE_DATA_ACK 0x50 /* Controller Receive Data ACK */ +#define MA35_M_RECE_DATA_NACK 0x58 /* Controller Receive Data NACK */ +#define MA35_BUS_ERROR 0x00 /* Bus error */ + +/* Target */ +#define MA35_S_REPEAT_START_STOP 0xa0 /* Target Transmit Repeat Start or Stop */ +#define MA35_S_TRAN_ADDR_ACK 0xa8 /* Target Transmit Address ACK */ +#define MA35_S_TRAN_DATA_ACK 0xb8 /* Target Transmit Data ACK */ +#define MA35_S_TRAN_DATA_NACK 0xc0 /* Target Transmit Data NACK */ +#define MA35_S_TRAN_LAST_DATA_ACK 0xc8 /* Target Transmit Last Data ACK */ +#define MA35_S_RECE_ADDR_ACK 0x60 /* Target Receive Address ACK */ +#define MA35_S_RECE_ARB_LOST 0x68 /* Target Receive Arbitration Lost */ +#define MA35_S_RECE_DATA_ACK 0x80 /* Target Receive Data ACK */ +#define MA35_S_RECE_DATA_NACK 0x88 /* Target Receive Data NACK */ + +/* GC Mode */ +#define MA35_GC_ADDR_ACK 0x70 /* GC mode Address ACK */ +#define MA35_GC_ARB_LOST 0x78 /* GC mode Arbitration Lost */ +#define MA35_GC_DATA_ACK 0x90 /* GC mode Data ACK */ +#define MA35_GC_DATA_NACK 0x98 /* GC mode Data NACK */ + +/* Other */ +#define MA35_ADDR_TRAN_ARB_LOST 0xb0 /* Address Transmit Arbitration Lost */ +#define MA35_BUS_RELEASED 0xf8 /* Bus Released */ + +/* I2C_CTL constant definitions. */ +#define MA35_CTL_AA BIT(2) +#define MA35_CTL_SI BIT(3) +#define MA35_CTL_STO BIT(4) +#define MA35_CTL_STA BIT(5) +#define MA35_CTL_I2CEN BIT(6) +#define MA35_CTL_INTEN BIT(7) +#define MA35_CTL_SI_AA (MA35_CTL_SI | MA35_CTL_AA) +#define MA35_CTL_STO_SI (MA35_CTL_STO | MA35_CTL_SI) +#define MA35_CTL_STA_SI (MA35_CTL_STA | MA35_CTL_SI) +#define MA35_CTL_STA_SI_AA (MA35_CTL_STA | MA35_CTL_SI | MA35_CTL_AA) +#define MA35_CTL_STO_SI_AA (MA35_CTL_STO | MA35_CTL_SI | MA35_CTL_AA) + +/* Constants */ +#define MA35_CLKDIV_MSK GENMASK(15, 0) +#define MA35_I2C_ADDR_MASK (0x7f << 1) +#define I2C_PM_TIMEOUT_MS 5000 +#define STOP_TIMEOUT_MS 50 +#define MA35_I2C_GC_EN 1 +#define MA35_I2C_GC_DIS 0 + +struct ma35d1_i2c { + spinlock_t lock; /* Protects I2C register access and state */ + wait_queue_head_t wait; + struct i2c_msg *msg; + unsigned int msg_num; + unsigned int msg_idx; + unsigned int msg_ptr; + unsigned int irq; + unsigned int arblost; + void __iomem *regs; + struct clk *clk; + struct device *dev; + struct i2c_adapter adap; + struct i2c_client *target; + struct reset_control *rst; +}; + +static inline bool ma35d1_is_controller_status(unsigned int status) +{ + return status >= MA35_M_START && status <= MA35_M_RECE_DATA_NACK; +} + +/* + * ma35d1_i2c_write_CTL - Update the I2C control register + * @i2c: Pointer to the ma35d1 i2c instance + * @ctl: Control bits to set (e.g., MA35_CTL_STA, SI, AA) + * + * This helper reads CTL0, clears the sticky state-change bits (STA, STO, SI, AA), + * and then applies the new control bits provided by @ctl. + */ +static void ma35d1_i2c_write_CTL(struct ma35d1_i2c *i2c, unsigned int ctl) +{ + unsigned int val; + + val = readl(i2c->regs + MA35_CTL0); + val &= ~(MA35_CTL_STA_SI_AA | MA35_CTL_STO); + val |= ctl; + writel(val, i2c->regs + MA35_CTL0); +} + +static void ma35d1_i2c_set_addr(struct ma35d1_i2c *i2c) +{ + unsigned int rw = i2c->msg->flags & I2C_M_RD; + + writel(((i2c->msg->addr & 0x7f) << 1) | rw, i2c->regs + MA35_DAT); +} + +static void ma35d1_i2c_controller_complete(struct ma35d1_i2c *i2c, int ret) +{ + dev_dbg(i2c->dev, "controller_complete %d\n", ret); + + i2c->msg_ptr = 0; + i2c->msg = NULL; + i2c->msg_idx++; + i2c->msg_num = 0; + if (ret) + i2c->msg_idx = ret; + + wake_up(&i2c->wait); +} + +static void ma35d1_i2c_disable_irq(struct ma35d1_i2c *i2c) +{ + unsigned long tmp; + + tmp = readl(i2c->regs + MA35_CTL0); + writel(tmp & ~MA35_CTL_INTEN, i2c->regs + MA35_CTL0); +} + +static void ma35d1_i2c_enable_irq(struct ma35d1_i2c *i2c) +{ + unsigned long tmp; + + tmp = readl(i2c->regs + MA35_CTL0); + writel(tmp | MA35_CTL_INTEN, i2c->regs + MA35_CTL0); +} + +static void ma35d1_i2c_reset(struct ma35d1_i2c *i2c) +{ + unsigned int tmp; + + tmp = readl(i2c->regs + MA35_CLKDIV); + + reset_control_assert(i2c->rst); + usleep_range(10, 20); + reset_control_deassert(i2c->rst); + + writel(tmp, (i2c->regs + MA35_CLKDIV)); + ma35d1_i2c_write_CTL(i2c, MA35_CTL_I2CEN); + + if (i2c->target) + ma35d1_i2c_write_CTL(i2c, MA35_CTL_SI_AA); +} + +static void ma35d1_i2c_stop(struct ma35d1_i2c *i2c, int ret) +{ + unsigned int val; + int err; + + /* Ensure AA is cleared to prevent the controller + * from re-claiming the bus unnecessarily + */ + if (readl(i2c->regs + MA35_CTL0) & MA35_CTL_AA) { + val = readl(i2c->regs + MA35_CTL0); + val &= ~MA35_CTL_AA; + writel(val, (i2c->regs + MA35_CTL0)); + + err = readl_poll_timeout_atomic(i2c->regs + MA35_CTL0, val, + !(val & MA35_CTL_AA), 1, 1000); + if (err) + dev_warn(i2c->dev, + "AA bit could not be cleared in time\n"); + } + + ma35d1_i2c_write_CTL(i2c, MA35_CTL_STO_SI); + + err = readl_poll_timeout_atomic(i2c->regs + MA35_CTL0, val, + !(val & MA35_CTL_STO), 1, 1 * 1000); + if (err) + dev_warn(i2c->dev, "I2C Stop Timeout\n"); + + if (i2c->target) + ma35d1_i2c_write_CTL(i2c, MA35_CTL_SI_AA); + else + ma35d1_i2c_disable_irq(i2c); + + ma35d1_i2c_controller_complete(i2c, ret); +} + +/* Check if this is the last message in the set */ +static inline bool is_last_msg(struct ma35d1_i2c *i2c) +{ + return i2c->msg_idx >= (i2c->msg_num - 1); +} + +/* Check if this is the last byte in the current message */ +static inline bool is_last_byte(struct ma35d1_i2c *i2c) +{ + return i2c->msg_ptr == i2c->msg->len - 1; +} + +/* Check if reached the end of the current message */ +static inline bool is_msgend(struct ma35d1_i2c *i2c) +{ + return i2c->msg_ptr >= i2c->msg->len; +} + +/* + * i2c_ma35d1_irq_target_trx - I2C Target state machine handler + * @i2c: ma35d1 i2c instance + * @i2c_status: hardware status code from MA35_STATUS0 + */ +static void i2c_ma35d1_irq_target_trx(struct ma35d1_i2c *i2c, + unsigned long i2c_status) +{ + unsigned char byte; + + switch (i2c_status) { + case MA35_S_RECE_ADDR_ACK: + /* Own SLA+W has been receive; ACK has been return */ + i2c_slave_event(i2c->target, I2C_SLAVE_WRITE_REQUESTED, &byte); + break; + case MA35_S_TRAN_DATA_NACK: + /* Data byte or last data in I2CDAT has been transmitted. + * Not ACK has been received + */ + case MA35_S_RECE_DATA_NACK: + /* Previously addressed with own SLA address; + * NOT ACK has been returned + */ + break; + + case MA35_S_RECE_DATA_ACK: + /* Previously address with own SLA address Data has been received; + * ACK has been returned + */ + byte = readb(i2c->regs + MA35_DAT); + i2c_slave_event(i2c->target, I2C_SLAVE_WRITE_RECEIVED, &byte); + break; + + case MA35_S_TRAN_ADDR_ACK: + /* Own SLA+R has been receive; ACK has been return */ + i2c_slave_event(i2c->target, I2C_SLAVE_READ_REQUESTED, &byte); + + writel(byte, i2c->regs + MA35_DAT); + break; + + case MA35_S_TRAN_DATA_ACK: + i2c_slave_event(i2c->target, I2C_SLAVE_READ_PROCESSED, &byte); + writel(byte, i2c->regs + MA35_DAT); + break; + + case MA35_S_REPEAT_START_STOP: + /* A STOP or repeated START has been received + * while still addressed as Target/Receiver + */ + i2c_slave_event(i2c->target, I2C_SLAVE_STOP, &byte); + break; + + default: + dev_err(i2c->dev, "Status 0x%02lx is NOT processed\n", + i2c_status); + break; + } + ma35d1_i2c_write_CTL(i2c, MA35_CTL_SI_AA); +} + +/* + * i2c_ma35d1_irq_controller_trx - I2C Controller state machine handler + * @i2c: ma35d1 i2c instance + * @i2c_status: hardware status code from MA35_STATUS0 + */ +static void i2c_ma35d1_irq_controller_trx(struct ma35d1_i2c *i2c, + unsigned long i2c_status) +{ + unsigned char byte; + + switch (i2c_status) { + case MA35_M_START: + case MA35_M_REPEAT_START: + ma35d1_i2c_set_addr(i2c); + ma35d1_i2c_write_CTL(i2c, MA35_CTL_SI); + break; + + case MA35_M_TRAN_ADDR_ACK: + case MA35_M_TRAN_DATA_ACK: + /* SLA+W has been transmitted and ACK has been received */ + if (i2c_status == MA35_M_TRAN_ADDR_ACK) { + if (is_last_msg(i2c) && i2c->msg->len == 0) { + ma35d1_i2c_stop(i2c, 0); + return; + } + } + + if (!is_msgend(i2c)) { + byte = i2c->msg->buf[i2c->msg_ptr++]; + writel(byte, i2c->regs + MA35_DAT); + ma35d1_i2c_write_CTL(i2c, MA35_CTL_SI); + } else if (!is_last_msg(i2c)) { + dev_dbg(i2c->dev, "WRITE: Next Message\n"); + + i2c->msg_ptr = 0; + i2c->msg_idx++; + i2c->msg++; + + ma35d1_i2c_write_CTL(i2c, MA35_CTL_STA | MA35_CTL_SI); + } else { + ma35d1_i2c_stop(i2c, 0); + } + break; + + case MA35_M_TRAN_DATA_NACK: + ma35d1_i2c_stop(i2c, 0); + break; + + case MA35_M_TRAN_ADDR_NACK: + case MA35_M_RECE_ADDR_NACK: + /* Controller Transmit Address NACK */ + /* 0x20: SLA+W has been transmitted and NACK has been received */ + /* 0x48: SLA+R has been transmitted and NACK has been received */ + if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) { + dev_dbg(i2c->dev, "\n i2c: ack was not received\n"); + ma35d1_i2c_stop(i2c, -ENXIO); + } + break; + + case MA35_M_RECE_ADDR_ACK: + if (is_last_msg(i2c) && i2c->msg->len == 0) + ma35d1_i2c_stop(i2c, 0); + else if (is_last_msg(i2c) && (i2c->msg->len == 1)) + ma35d1_i2c_write_CTL(i2c, MA35_CTL_SI); + else + ma35d1_i2c_write_CTL(i2c, MA35_CTL_SI_AA); + break; + + case MA35_M_RECE_DATA_ACK: + case MA35_M_RECE_DATA_NACK: + /* DATA has been transmitted and ACK has been received */ + byte = readb(i2c->regs + MA35_DAT); + i2c->msg->buf[i2c->msg_ptr++] = byte; + + if (is_last_byte(i2c)) { + ma35d1_i2c_write_CTL(i2c, MA35_CTL_SI); + } else if (is_msgend(i2c)) { + if (is_last_msg(i2c)) { + dev_dbg(i2c->dev, "READ: Send Stop\n"); + + ma35d1_i2c_stop(i2c, 0); + } else { + dev_dbg(i2c->dev, "READ: Next Transfer\n"); + + i2c->msg_ptr = 0; + i2c->msg_idx++; + i2c->msg++; + + ma35d1_i2c_write_CTL(i2c, MA35_CTL_STA_SI); + } + } else { + ma35d1_i2c_write_CTL(i2c, MA35_CTL_SI_AA); + } + break; + + default: + dev_err(i2c->dev, "Status 0x%02lx is NOT processed\n", + i2c_status); + ma35d1_i2c_disable_irq(i2c); + ma35d1_i2c_stop(i2c, 0); + break; + } +} + +static irqreturn_t ma35d1_i2c_irq(int irqno, void *dev_id) +{ + struct ma35d1_i2c *i2c = dev_id; + unsigned long status, flags; + + status = readl(i2c->regs + MA35_STATUS0); + + spin_lock_irqsave(&i2c->lock, flags); + + if (status == MA35_M_ARB_LOST) { + dev_err(i2c->dev, "Arbitration lost\n"); + i2c->arblost = 1; + ma35d1_i2c_disable_irq(i2c); + ma35d1_i2c_stop(i2c, -EAGAIN); + goto out; + } + + else if (status == MA35_BUS_ERROR) { + dev_err(i2c->dev, "Bus error during transfer\n"); + ma35d1_i2c_disable_irq(i2c); + ma35d1_i2c_stop(i2c, 0); + goto out; + } + + if (ma35d1_is_controller_status(status)) + i2c_ma35d1_irq_controller_trx(i2c, status); + else + i2c_ma35d1_irq_target_trx(i2c, status); + +out: + spin_unlock_irqrestore(&i2c->lock, flags); + return IRQ_HANDLED; +} + +static int ma35d1_i2c_doxfer(struct ma35d1_i2c *i2c, struct i2c_msg *msgs, + int num) +{ + unsigned long timeout; + unsigned int val; + int ret, err; + + spin_lock_irq(&i2c->lock); + + ma35d1_i2c_enable_irq(i2c); + + i2c->msg = msgs; + i2c->msg_num = num; + i2c->msg_ptr = 0; + i2c->msg_idx = 0; + + ma35d1_i2c_write_CTL(i2c, MA35_CTL_SI | MA35_CTL_STA); + spin_unlock_irq(&i2c->lock); + + timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5); + ret = i2c->msg_idx; + + if (timeout == 0) + dev_dbg(i2c->dev, "timeout\n"); + else if (ret != num) + dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret); + + err = readl_poll_timeout(i2c->regs + MA35_CTL0, val, + !(val & MA35_CTL_STO), 100, + STOP_TIMEOUT_MS * 1000); + + if (err) { + dev_err(i2c->dev, "Bus stuck! Resetting controller...\n"); + ma35d1_i2c_reset(i2c); + } + + if (i2c->arblost) { + dev_dbg(i2c->dev, "arb lost, stop\n"); + i2c->arblost = 0; + } + + return ret; +} + +static int ma35d1_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, + int num) +{ + struct ma35d1_i2c *i2c = i2c_get_adapdata(adap); + int retry, ret; + + ret = pm_runtime_resume_and_get(i2c->dev); + if (ret) + return ret; + + for (retry = 0; retry < adap->retries; retry++) { + ret = ma35d1_i2c_doxfer(i2c, msgs, num); + + if (ret != -EAGAIN) + break; + + dev_dbg(i2c->dev, "Retrying transmission (%d)\n", retry); + fsleep(100); + } + + if (ret == -EAGAIN) + ret = -EREMOTEIO; + + pm_runtime_put_autosuspend(i2c->dev); + + return ret; +} + +static int ma35d1_reg_target(struct i2c_client *target) +{ + struct ma35d1_i2c *i2c = i2c_get_adapdata(target->adapter); + unsigned int val, slvaddr; + int ret; + + if (i2c->target) + return -EBUSY; + + if (target->flags & I2C_CLIENT_TEN) + return -EAFNOSUPPORT; + + ma35d1_i2c_enable_irq(i2c); + + ret = pm_runtime_resume_and_get(i2c->dev); + if (ret) { + dev_err(i2c->dev, "failed to resume i2c controller\n"); + return ret; + } + + i2c->target = target; + + val = readl(i2c->regs + MA35_CTL0); + val |= MA35_CTL_I2CEN; + writel(val, i2c->regs + MA35_CTL0); + slvaddr = target->addr << 1; + writel(slvaddr, i2c->regs + MA35_ADDR0); + + /* I2C enter SLV mode */ + ma35d1_i2c_write_CTL(i2c, MA35_CTL_SI_AA); + + return 0; +} + +static int ma35d1_unreg_target(struct i2c_client *target) +{ + struct ma35d1_i2c *i2c = i2c_get_adapdata(target->adapter); + unsigned int val; + int ret; + + /* Disable I2C */ + val = readl(i2c->regs + MA35_CTL0); + val &= ~MA35_CTL_I2CEN; + writel(val, i2c->regs + MA35_CTL0); + + /* Disable I2C interrupt */ + ma35d1_i2c_disable_irq(i2c); + + i2c->target = NULL; + + ret = pm_runtime_put_sync(i2c->dev); + if (ret) + dev_err(i2c->dev, "failed to suspend i2c controller"); + + return 0; +} + +/* Declare Our I2C Functionality */ +static u32 ma35d1_i2c_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_PROTOCOL_MANGLING | I2C_FUNC_SMBUS_EMUL; +} + +/* I2C Bus Registration Info */ +static const struct i2c_algorithm ma35d1_i2c_algorithm = { + .xfer = ma35d1_i2c_xfer, + .functionality = ma35d1_i2c_func, + .reg_target = ma35d1_reg_target, + .unreg_target = ma35d1_unreg_target, +}; + +static int ma35d1_i2c_probe(struct platform_device *pdev) +{ + struct ma35d1_i2c *i2c; + struct resource *res; + int ret, clkdiv; + unsigned int busfreq; + struct device *dev = &pdev->dev; + + i2c = devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL); + if (!i2c) + return -ENOMEM; + + spin_lock_init(&i2c->lock); + init_waitqueue_head(&i2c->wait); + + i2c->dev = dev; + + i2c->clk = devm_clk_get_prepared(dev, NULL); + if (IS_ERR(i2c->clk)) + return dev_err_probe(dev, PTR_ERR(i2c->clk), + "failed to get core clk\n"); + + i2c->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res); + if (IS_ERR(i2c->regs)) + return PTR_ERR(i2c->regs); + + i2c->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL); + if (IS_ERR(i2c->rst)) + return dev_err_probe(dev, PTR_ERR(i2c->rst), + "failed to get reset control\n"); + + /* Setup info block for the I2C core */ + strscpy(i2c->adap.name, "ma35d1-i2c", sizeof(i2c->adap.name)); + i2c->adap.owner = THIS_MODULE; + i2c->adap.algo = &ma35d1_i2c_algorithm; + i2c->adap.retries = 2; + i2c->adap.algo_data = i2c; + i2c->adap.dev.parent = &pdev->dev; + i2c->adap.dev.of_node = pdev->dev.of_node; + i2c_set_adapdata(&i2c->adap, i2c); + + /* Default to 100kHz if not specified in DT */ + busfreq = 100000; + device_property_read_u32(dev, "clock-frequency", &busfreq); + + /* Calculate divider based on the current peripheral clock rate */ + clkdiv = DIV_ROUND_CLOSEST(clk_get_rate(i2c->clk), busfreq * 4) - 1; + if (clkdiv < 0 || clkdiv > 0xffff) + return dev_err_probe(dev, -EINVAL, "invalid clkdiv value: %d\n", + clkdiv); + + i2c->irq = platform_get_irq(pdev, 0); + if (i2c->irq < 0) + return dev_err_probe(dev, i2c->irq, "failed to get irq\n"); + + platform_set_drvdata(pdev, i2c); + + pm_runtime_set_autosuspend_delay(dev, I2C_PM_TIMEOUT_MS); + pm_runtime_use_autosuspend(dev); + devm_pm_runtime_enable(dev); + + ret = pm_runtime_resume_and_get(dev); + if (ret) + return dev_err_probe(dev, ret, "failed to resume device\n"); + + writel(FIELD_PREP(MA35_CLKDIV_MSK, clkdiv), i2c->regs + MA35_CLKDIV); + + ret = devm_request_irq(dev, i2c->irq, ma35d1_i2c_irq, IRQF_SHARED, + dev_name(dev), i2c); + if (ret) { + dev_err_probe(dev, ret, "cannot claim IRQ %d\n", i2c->irq); + goto rpm_put; + } + + ret = devm_i2c_add_adapter(dev, &i2c->adap); + if (ret) { + dev_err_probe(dev, ret, "failed to add bus to i2c core\n"); + goto rpm_put; + } + + pm_runtime_put_autosuspend(dev); + + return 0; + +rpm_put: + pm_runtime_put_noidle(dev); + return ret; +} + +static int ma35d1_i2c_suspend(struct device *dev) +{ + struct ma35d1_i2c *i2c = dev_get_drvdata(dev); + unsigned int val; + + spin_lock_irq(&i2c->lock); + + /* Prepare for wake-up from I2C events if target mode is active */ + if (i2c->target) { + val = readl(i2c->regs + MA35_CTL0); + val |= (MA35_CTL_SI | MA35_CTL_AA); + writel(val, i2c->regs + MA35_CTL0); + ma35d1_i2c_enable_irq(i2c); + } + + spin_unlock_irq(&i2c->lock); + + /* Setup wake-up control */ + writel(0x1, i2c->regs + MA35_WKCTL); + + /* Clear pending wake-up flags */ + val = readl(i2c->regs + MA35_WKSTS); + writel(val, i2c->regs + MA35_WKSTS); + + enable_irq_wake(i2c->irq); + + return 0; +} + +static int ma35d1_i2c_resume(struct device *dev) +{ + struct ma35d1_i2c *i2c = dev_get_drvdata(dev); + unsigned int val; + + /* Disable wake-up */ + writel(0x0, i2c->regs + MA35_WKCTL); + + /* Clear pending wake-up flags */ + val = readl(i2c->regs + MA35_WKSTS); + writel(val, i2c->regs + MA35_WKSTS); + + disable_irq_wake(i2c->irq); + + return 0; +} + +static int ma35d1_i2c_runtime_suspend(struct device *dev) +{ + struct ma35d1_i2c *i2c = dev_get_drvdata(dev); + unsigned int val; + + /* Disable I2C controller */ + val = readl(i2c->regs + MA35_CTL0); + val &= ~MA35_CTL_I2CEN; + writel(val, i2c->regs + MA35_CTL0); + + clk_disable(i2c->clk); + + return 0; +} + +static int ma35d1_i2c_runtime_resume(struct device *dev) +{ + struct ma35d1_i2c *i2c = dev_get_drvdata(dev); + unsigned int val; + int ret; + + ret = clk_enable(i2c->clk); + if (ret) { + dev_err(dev, "failed to enable clock in resume\n"); + return ret; + } + + /* Enable I2C controller */ + val = readl(i2c->regs + MA35_CTL0); + val |= MA35_CTL_I2CEN; + writel(val, i2c->regs + MA35_CTL0); + + return 0; +} + +static const struct dev_pm_ops ma35d1_i2c_pmops = { + SYSTEM_SLEEP_PM_OPS(ma35d1_i2c_suspend, ma35d1_i2c_resume) + RUNTIME_PM_OPS(ma35d1_i2c_runtime_suspend, + ma35d1_i2c_runtime_resume, NULL) +}; + +static const struct of_device_id ma35d1_i2c_of_match[] = { + { .compatible = "nuvoton,ma35d1-i2c" }, + {}, +}; +MODULE_DEVICE_TABLE(of, ma35d1_i2c_of_match); + +static struct platform_driver ma35d1_i2c_driver = { + .probe = ma35d1_i2c_probe, + .driver = { + .name = "ma35d1-i2c", + .of_match_table = ma35d1_i2c_of_match, + .pm = pm_ptr(&ma35d1_i2c_pmops), + }, +}; +module_platform_driver(ma35d1_i2c_driver); + +MODULE_AUTHOR("Zi-Yu Chen "); +MODULE_DESCRIPTION("MA35D1 I2C Bus Driver"); +MODULE_LICENSE("GPL"); -- 2.34.1