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The existing Qualcomm I2C controller drivers, GENI and QUP, are master-only and cannot serve systems where the SoC must respond as an I2C target on the bus. Register the controller with the Linux I2C slave framework through i2c_algorithm.reg_slave and i2c_algorithm.unreg_slave. This allows standard slave backends, such as slave-24c02, to be attached at runtime through i2c_slave_register(). Handle IRQ events for RX FIFO service, clock stretching during read and write phases, STOP and repeated-start conditions, and error recovery through a software reset. Enable the required AHB and XO clocks and vote for interconnect bandwidth. Restore the hardware state across system suspend and resume using regular system-sleep PM callbacks. Signed-off-by: Viken Dadhaniya --- MAINTAINERS | 9 + drivers/i2c/busses/Kconfig | 15 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-qcom-target.c | 628 +++++++++++++++++++++++++++++++++++ 4 files changed, 653 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index 06760c45c582..07ade6c1dfdf 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -22670,6 +22670,15 @@ S: Maintained F: Documentation/devicetree/bindings/i2c/qcom,i2c-geni-qcom.yaml F: drivers/i2c/busses/i2c-qcom-geni.c +QUALCOMM I2C TARGET CONTROLLER DRIVER +M: Viken Dadhaniya +M: Mukesh Kumar Savaliya +L: linux-i2c@vger.kernel.org +L: linux-arm-msm@vger.kernel.org +S: Maintained +F: Documentation/devicetree/bindings/i2c/qcom,qdu1000-i2c-target.yaml +F: drivers/i2c/busses/i2c-qcom-target.c + QUALCOMM I2C CCI DRIVER M: Loic Poulain M: Robert Foss diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index d7b89508311f..2e18238e0ae6 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -1070,6 +1070,21 @@ config I2C_QCOM_GENI This driver can also be built as a module. If so, the module will be called i2c-qcom-geni. +config I2C_QCOM_TARGET + tristate "Qualcomm I2C target controller" + depends on ARCH_QCOM || COMPILE_TEST + depends on COMMON_CLK + depends on INTERCONNECT + select I2C_SLAVE + help + This driver supports I2C target mode on Qualcomm Technologies + SoCs. If you say yes to this option, support will be included + for the built-in I2C target controller on QDU1000 and other + compatible Qualcomm SoCs. + + This driver can also be built as a module. If so, the module + will be called i2c-qcom-target. + config I2C_QUP tristate "Qualcomm QUP based I2C controller" depends on ARCH_QCOM || COMPILE_TEST diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 3755c54b3d82..ab3070cdb144 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -101,6 +101,7 @@ obj-$(CONFIG_I2C_PXA) += i2c-pxa.o obj-$(CONFIG_I2C_PXA_PCI) += i2c-pxa-pci.o obj-$(CONFIG_I2C_QCOM_CCI) += i2c-qcom-cci.o obj-$(CONFIG_I2C_QCOM_GENI) += i2c-qcom-geni.o +obj-$(CONFIG_I2C_QCOM_TARGET) += i2c-qcom-target.o obj-$(CONFIG_I2C_QUP) += i2c-qup.o obj-$(CONFIG_I2C_RIIC) += i2c-riic.o obj-$(CONFIG_I2C_RK3X) += i2c-rk3x.o diff --git a/drivers/i2c/busses/i2c-qcom-target.c b/drivers/i2c/busses/i2c-qcom-target.c new file mode 100644 index 000000000000..5cf4bad1b601 --- /dev/null +++ b/drivers/i2c/busses/i2c-qcom-target.c @@ -0,0 +1,628 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* Register offsets */ +#define I2C_S_DEVICE_ADDR 0x00 +#define I2C_S_IRQ_STATUS 0x08 +#define I2C_S_IRQ_CLR 0x0C +#define I2C_S_IRQ_EN 0x10 +#define I2C_S_CONFIG 0x18 +#define I2C_S_CONTROL 0x1C +#define I2C_S_FIFOS_STATUS 0x20 +#define I2C_S_TX_FIFO 0x24 +#define I2C_S_RX_FIFO 0x28 +#define I2C_S_DEBUG_REG1 0x3C +#define I2C_S_DEBUG_REG2 0x40 +#define I2C_S_SW_RESET_REG 0x4C +#define I2C_S_CLK_LOW_TIMEOUT 0x50 +#define I2C_S_CLK_RELEASE_DELAY_CNT_VAL 0x54 +#define I2C_S_SDA_HOLD_CNT_VAL 0x58 + +/* I2C_S_CONFIG register fields */ +#define I2C_S_CORE_EN BIT(0) + +/* I2C_S_CONTROL register fields */ +#define CLEAR_RX_FIFO BIT(0) +#define CLEAR_TX_FIFO BIT(1) +#define NACK BIT(2) +#define ACK_RESUME BIT(3) + +/* I2C_S_SW_RESET_REG register fields */ +#define SW_RESET BIT(0) + +/* I2C_S_FIFOS_STATUS register fields */ +#define RX_FIFO_COUNT_MASK GENMASK(31, 16) + +/* Interconnect bandwidth vote in bytes per second */ +#define APPS_PROC_TO_I2C_TARGET_VOTE 1190000 + +/** + * enum qcom_i2c_target_irq - IRQ bit positions in I2C_S_IRQ_STATUS + * @STOP_DETECTED: I2C stop condition detected on the bus + * @RX_FIFO_FULL: receive FIFO has reached capacity + * @TX_FIFO_EMPTY: transmit FIFO is empty + * @RX_DATA_AVAIL: receive data is available in the RX FIFO + * @CLOCK_LOW_TIMEOUT: SCL held low longer than the configured timeout + * @STRCH_WR: clock stretching during a write (Rx) phase + * @STRCH_RD: clock stretching during a read (Tx) phase + * @GCA_DETECTED: general call address detected (not used) + * @ERR_CONDITION: unexpected start or stop bit detected (error) + * @RESTART_DETECTED: repeated start condition detected + */ +enum qcom_i2c_target_irq { + STOP_DETECTED, + RX_FIFO_FULL, + TX_FIFO_EMPTY, + RX_DATA_AVAIL, + CLOCK_LOW_TIMEOUT, + STRCH_WR, + STRCH_RD, + GCA_DETECTED, + ERR_CONDITION, + RESTART_DETECTED, +}; + +/* + * TX_FIFO_EMPTY is excluded: this driver fills the TX FIFO one byte at a + * time in response to STRCH_RD (clock-stretch during read phase), so + * TX_FIFO_EMPTY adds no value and would double the interrupt rate. + * GCA (general call address) is unsupported. + */ +#define QCOM_I2C_TARGET_ALL_IRQ (GENMASK(RESTART_DETECTED, STOP_DETECTED) \ + & ~(BIT(GCA_DETECTED) | BIT(TX_FIFO_EMPTY))) + +/* Bit indices for the status bitmask, used with set_bit/test_bit/clear_bit */ +enum qcom_i2c_target_status { + READ_IN_PROGRESS, + WRITE_IN_PROGRESS, +}; + +/** + * struct qcom_i2c_target - Qualcomm I2C target controller private data + * @dev: driver model device node + * @base: base address of HW registers + * @adap: I2C adapter (slave mode) + * @ahb_clk: AHB bus clock + * @xo_clk: XO reference clock + * @icc_path: interconnect bandwidth path + * @slave: currently registered slave backend client; written only + * under disable_irq() in reg_slave()/unreg_slave() so the + * ISR sees a stable pointer for its entire execution + * @status: bitmask of enum qcom_i2c_target_status flags; must be + * unsigned long for set_bit/test_bit/clear_bit; accessed + * only from the ISR and from reg_slave()/unreg_slave() + * under disable_irq(), so no additional lock is needed + * @irq: interrupt line number + */ +struct qcom_i2c_target { + struct device *dev; + void __iomem *base; + struct i2c_adapter adap; + struct clk *ahb_clk; + struct clk *xo_clk; + struct icc_path *icc_path; + struct i2c_client *slave; + unsigned long status; + int irq; +}; + +static void qcom_i2c_target_dump_regs(struct qcom_i2c_target *target) +{ + dev_dbg(target->dev, "I2C_S_DEVICE_ADDR: 0x%x\n", + readl_relaxed(target->base + I2C_S_DEVICE_ADDR)); + dev_dbg(target->dev, "I2C_S_IRQ_STATUS: 0x%x\n", + readl_relaxed(target->base + I2C_S_IRQ_STATUS)); + dev_dbg(target->dev, "I2C_S_CONFIG: 0x%x\n", + readl_relaxed(target->base + I2C_S_CONFIG)); + dev_dbg(target->dev, "I2C_S_IRQ_EN: 0x%x\n", + readl_relaxed(target->base + I2C_S_IRQ_EN)); + dev_dbg(target->dev, "I2C_S_FIFOS_STATUS: 0x%x\n", + readl_relaxed(target->base + I2C_S_FIFOS_STATUS)); + dev_dbg(target->dev, "I2C_S_DEBUG_REG1: 0x%x\n", + readl_relaxed(target->base + I2C_S_DEBUG_REG1)); + dev_dbg(target->dev, "I2C_S_DEBUG_REG2: 0x%x\n", + readl_relaxed(target->base + I2C_S_DEBUG_REG2)); + dev_dbg(target->dev, "I2C_S_CLK_LOW_TIMEOUT: 0x%x\n", + readl_relaxed(target->base + I2C_S_CLK_LOW_TIMEOUT)); + dev_dbg(target->dev, "I2C_S_CLK_RELEASE_DELAY_CNT_VAL: 0x%x\n", + readl_relaxed(target->base + I2C_S_CLK_RELEASE_DELAY_CNT_VAL)); + dev_dbg(target->dev, "I2C_S_SDA_HOLD_CNT_VAL: 0x%x\n", + readl_relaxed(target->base + I2C_S_SDA_HOLD_CNT_VAL)); +} + +static void qcom_i2c_target_hw_init(struct qcom_i2c_target *target) +{ + dev_dbg(target->dev, "HW init: resetting FIFOs, enabling IRQs\n"); + writel(CLEAR_TX_FIFO | CLEAR_RX_FIFO, target->base + I2C_S_CONTROL); + writel(QCOM_I2C_TARGET_ALL_IRQ, target->base + I2C_S_IRQ_EN); +} + +static void qcom_i2c_target_write_requested(struct qcom_i2c_target *target) +{ + u8 val = 0; + + if (!test_and_set_bit(WRITE_IN_PROGRESS, &target->status)) { + dev_dbg(target->dev, "Write phase started\n"); + i2c_slave_event(target->slave, I2C_SLAVE_WRITE_REQUESTED, &val); + } +} + +static int qcom_i2c_target_drain_rx_fifo(struct qcom_i2c_target *target) +{ + unsigned int rx_count; + int ret = 0; + u8 val; + + while (!ret) { + rx_count = FIELD_GET(RX_FIFO_COUNT_MASK, + readl_relaxed(target->base + I2C_S_FIFOS_STATUS)); + if (!rx_count) + break; + + while (rx_count--) { + val = (u8)readl_relaxed(target->base + I2C_S_RX_FIFO); + dev_dbg(target->dev, "Data from RX FIFO: 0x%x\n", val); + ret = i2c_slave_event(target->slave, I2C_SLAVE_WRITE_RECEIVED, &val); + if (ret) + break; + } + } + + return ret; +} + +static void qcom_i2c_target_hw_reset(struct qcom_i2c_target *target) +{ + /* Clear error bits before SW_RESET; the reset may not be instantaneous */ + writel(BIT(ERR_CONDITION) | BIT(CLOCK_LOW_TIMEOUT), + target->base + I2C_S_IRQ_CLR); + writel(SW_RESET, target->base + I2C_S_SW_RESET_REG); + + /* + * I2C_S_SW_RESET_REG is write-only so completion cannot be polled. + * This helper is called from the hard IRQ handler, so the reset delay + * must not sleep. Use a short busy wait before reconfiguring the + * controller. + */ + udelay(20); + qcom_i2c_target_hw_init(target); + writel(target->slave->addr, target->base + I2C_S_DEVICE_ADDR); + writel(I2C_S_CORE_EN, target->base + I2C_S_CONFIG); +} + +static irqreturn_t qcom_i2c_target_handle_error(struct qcom_i2c_target *target, + u32 irq_stat) +{ + u8 val = 0; + + if (irq_stat & BIT(ERR_CONDITION)) + dev_err(target->dev, "Error condition: unexpected Start/Stop bits\n"); + else + dev_err(target->dev, "Clock low timeout\n"); + qcom_i2c_target_dump_regs(target); + qcom_i2c_target_hw_reset(target); + i2c_slave_event(target->slave, I2C_SLAVE_STOP, &val); + target->status = 0; + + return IRQ_HANDLED; +} + +static irqreturn_t qcom_i2c_target_handle_stop(struct qcom_i2c_target *target, + u32 irq_stat) +{ + u8 val = 0; + + dev_dbg(target->dev, "Stop bit detected\n"); + /* + * Short-write corner case: WRITE_IN_PROGRESS was never set because + * no RX_DATA_AVAIL or STRCH_WR fired before STOP. Do not call + * qcom_i2c_target_write_requested() here — STOP ends the transaction + * so setting WRITE_IN_PROGRESS now would leave a stale bit after + * target->status is cleared below. + */ + if (!test_bit(WRITE_IN_PROGRESS, &target->status)) { + unsigned int rx_count; + + rx_count = FIELD_GET(RX_FIFO_COUNT_MASK, + readl_relaxed(target->base + I2C_S_FIFOS_STATUS)); + if (rx_count) + i2c_slave_event(target->slave, I2C_SLAVE_WRITE_REQUESTED, + &val); + } + + qcom_i2c_target_drain_rx_fifo(target); + i2c_slave_event(target->slave, I2C_SLAVE_STOP, &val); + target->status = 0; + writel(CLEAR_RX_FIFO, target->base + I2C_S_CONTROL); + /* + * STOP terminates the transaction, so any other Rx or clock + * stretch bits latched in this same status read have already + * been serviced by the drain above or are now stale. Ack the + * whole word rather than just STOP_DETECTED; clearing only STOP + * would leave those bits set and immediately re-enter the + * handler, which for a co-asserted STRCH_RD would push a stale + * byte into the TX FIFO. + */ + writel(irq_stat, target->base + I2C_S_IRQ_CLR); + + return IRQ_HANDLED; +} + +static void qcom_i2c_target_handle_rx_data(struct qcom_i2c_target *target, + u32 rx_irq_bits) +{ + int ret; + + dev_dbg(target->dev, "Rx data event (rx_irq_bits=0x%x)\n", rx_irq_bits); + qcom_i2c_target_write_requested(target); + ret = qcom_i2c_target_drain_rx_fifo(target); + if (ret) + dev_dbg(target->dev, "Backend requested NACK\n"); + + writel(ret ? NACK | CLEAR_RX_FIFO : ACK_RESUME, + target->base + I2C_S_CONTROL); + writel(rx_irq_bits, target->base + I2C_S_IRQ_CLR); +} + +static void qcom_i2c_target_handle_strch_rd(struct qcom_i2c_target *target) +{ + enum i2c_slave_event event = I2C_SLAVE_READ_PROCESSED; + u8 val = 0; + + dev_dbg(target->dev, "Clock stretching during read (Tx) phase\n"); + if (!test_and_set_bit(READ_IN_PROGRESS, &target->status)) { + /* Repeated-start: master switched direction from write to read */ + clear_bit(WRITE_IN_PROGRESS, &target->status); + event = I2C_SLAVE_READ_REQUESTED; + } + + i2c_slave_event(target->slave, event, &val); + dev_dbg(target->dev, "Data to TX FIFO: 0x%x\n", val); + writel(val, target->base + I2C_S_TX_FIFO); + writel(ACK_RESUME, target->base + I2C_S_CONTROL); + writel(BIT(STRCH_RD), target->base + I2C_S_IRQ_CLR); +} + +static irqreturn_t qcom_i2c_target_irq(int irq, void *dev) +{ + struct qcom_i2c_target *target = dev; + u32 irq_stat, rx_bits; + + /* + * Dispatch priority (highest first): + * ERR_CONDITION / CLOCK_LOW_TIMEOUT — hardware error, triggers SW reset + * STOP_DETECTED — end of transaction, clears all state + * RESTART_DETECTED — repeated start, resets state before + * any data phase in the same snapshot + * STRCH_RD — read-phase data supply + * RX_FIFO_FULL / RX_DATA_AVAIL / + * STRCH_WR — write-phase Rx, coalesced into one drain + */ + irq_stat = readl_relaxed(target->base + I2C_S_IRQ_STATUS); + if (!irq_stat) + return IRQ_NONE; + + dev_dbg(target->dev, "IRQ status: 0x%x\n", irq_stat); + + /* + * Load target->slave once. Both reg_slave() and unreg_slave() disable + * the IRQ before writing the pointer, so it cannot change while this + * handler runs. Sub-handlers may dereference target->slave directly. + * + * The core is enabled only in reg_slave() and disabled in unreg_slave(), + * so no bus activity is expected here. Clear and discard any stale IRQ. + */ + if (!READ_ONCE(target->slave)) { + writel(irq_stat, target->base + I2C_S_IRQ_CLR); + return IRQ_HANDLED; + } + + if (irq_stat & (BIT(ERR_CONDITION) | BIT(CLOCK_LOW_TIMEOUT))) + return qcom_i2c_target_handle_error(target, irq_stat); + + if (irq_stat & BIT(STOP_DETECTED)) + return qcom_i2c_target_handle_stop(target, irq_stat); + + if (irq_stat & BIT(RESTART_DETECTED)) { + dev_dbg(target->dev, "Repeated start bit detected\n"); + target->status = 0; + /* + * Keep clock stretch asserted when STRCH_RD is co-asserted so + * qcom_i2c_target_handle_strch_rd() can fill TX FIFO first. + */ + if (!(irq_stat & BIT(STRCH_RD))) + writel(ACK_RESUME, target->base + I2C_S_CONTROL); + writel(BIT(RESTART_DETECTED), target->base + I2C_S_IRQ_CLR); + } + + if (irq_stat & BIT(STRCH_RD)) + qcom_i2c_target_handle_strch_rd(target); + + /* + * Coalesce all write-phase Rx bits into a single drain+ACK. When the + * RX FIFO fills at threshold, RX_FIFO_FULL, RX_DATA_AVAIL and STRCH_WR + * can all assert in the same irq_stat snapshot. Pass the combined mask + * so ACK_RESUME is written exactly once and all bits are cleared together. + */ + rx_bits = irq_stat & (BIT(RX_FIFO_FULL) | BIT(RX_DATA_AVAIL) | + BIT(STRCH_WR)); + if (rx_bits) + qcom_i2c_target_handle_rx_data(target, rx_bits); + + return IRQ_HANDLED; +} + +static int qcom_i2c_target_reg_slave(struct i2c_client *slave) +{ + struct qcom_i2c_target *target = i2c_get_adapdata(slave->adapter); + + if (target->slave) + return -EBUSY; + + if (slave->flags & I2C_CLIENT_TEN) + return -EAFNOSUPPORT; + + disable_irq(target->irq); + WRITE_ONCE(target->slave, slave); + writel(slave->addr, target->base + I2C_S_DEVICE_ADDR); + writel(I2C_S_CORE_EN, target->base + I2C_S_CONFIG); + enable_irq(target->irq); + + return 0; +} + +static int qcom_i2c_target_unreg_slave(struct i2c_client *slave) +{ + struct qcom_i2c_target *target = i2c_get_adapdata(slave->adapter); + + if (!target->slave) + return -EINVAL; + + disable_irq(target->irq); + writel(0, target->base + I2C_S_CONFIG); + WRITE_ONCE(target->slave, NULL); + target->status = 0; + writel(0, target->base + I2C_S_DEVICE_ADDR); + enable_irq(target->irq); + + return 0; +} + +static int qcom_i2c_target_icc_init(struct qcom_i2c_target *target) +{ + int ret; + + target->icc_path = devm_of_icc_get(target->dev, NULL); + if (IS_ERR(target->icc_path)) + return dev_err_probe(target->dev, PTR_ERR(target->icc_path), + "failed to get ICC path\n"); + + /* + * The controller only needs interconnect bandwidth while it is + * powered. The vote is placed here and across resume with + * icc_set_bw(), and dropped with icc_set_bw(path, 0, 0) on suspend + * and remove, so the vote and unvote are always symmetric. + */ + ret = icc_set_bw(target->icc_path, APPS_PROC_TO_I2C_TARGET_VOTE, + APPS_PROC_TO_I2C_TARGET_VOTE); + if (ret) + return dev_err_probe(target->dev, ret, "icc_set_bw failed\n"); + + return 0; +} + +static u32 qcom_i2c_target_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_SLAVE; +} + +static const struct i2c_algorithm qcom_i2c_target_algo = { + .reg_target = qcom_i2c_target_reg_slave, + .unreg_target = qcom_i2c_target_unreg_slave, + .functionality = qcom_i2c_target_func, +}; + +static int qcom_i2c_target_adap_init(struct qcom_i2c_target *target) +{ + target->adap.algo = &qcom_i2c_target_algo; + target->adap.dev.parent = target->dev; + target->adap.dev.of_node = target->dev->of_node; + strscpy(target->adap.name, "qcom-i2c-target", + sizeof(target->adap.name)); + i2c_set_adapdata(&target->adap, target); + + return i2c_add_adapter(&target->adap); +} + +static int qcom_i2c_target_probe(struct platform_device *pdev) +{ + struct qcom_i2c_target *target; + struct device *dev = &pdev->dev; + int ret; + + target = devm_kzalloc(dev, sizeof(*target), GFP_KERNEL); + if (!target) + return -ENOMEM; + + target->dev = dev; + + target->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(target->base)) + return dev_err_probe(dev, PTR_ERR(target->base), + "failed to map registers\n"); + + target->xo_clk = devm_clk_get(dev, "xo"); + if (IS_ERR(target->xo_clk)) + return dev_err_probe(dev, PTR_ERR(target->xo_clk), + "failed to get XO clock\n"); + + target->ahb_clk = devm_clk_get(dev, "ahb"); + if (IS_ERR(target->ahb_clk)) + return dev_err_probe(dev, PTR_ERR(target->ahb_clk), + "failed to get AHB clock\n"); + + ret = clk_prepare_enable(target->xo_clk); + if (ret) + return dev_err_probe(dev, ret, "failed to enable XO clock\n"); + + ret = clk_prepare_enable(target->ahb_clk); + if (ret) { + dev_err_probe(dev, ret, "failed to enable AHB clock\n"); + goto err_disable_xo; + } + + target->irq = platform_get_irq(pdev, 0); + if (target->irq < 0) { + ret = target->irq; + goto err_disable_ahb; + } + + ret = qcom_i2c_target_icc_init(target); + if (ret) + goto err_disable_ahb; + + ret = devm_request_irq(dev, target->irq, qcom_i2c_target_irq, 0, + dev_name(dev), target); + if (ret) { + dev_err_probe(dev, ret, "request_irq failed for IRQ %d\n", + target->irq); + goto err_disable_icc; + } + + qcom_i2c_target_hw_init(target); + + platform_set_drvdata(pdev, target); + + ret = qcom_i2c_target_adap_init(target); + if (ret) { + dev_err_probe(dev, ret, "i2c_add_adapter failed\n"); + goto err_free_irq; + } + + return 0; + +err_free_irq: + devm_free_irq(dev, target->irq, target); +err_disable_icc: + icc_set_bw(target->icc_path, 0, 0); +err_disable_ahb: + clk_disable_unprepare(target->ahb_clk); +err_disable_xo: + clk_disable_unprepare(target->xo_clk); + + return ret; +} + +static void qcom_i2c_target_remove(struct platform_device *pdev) +{ + struct qcom_i2c_target *target = platform_get_drvdata(pdev); + + writel(0, target->base + I2C_S_CONFIG); + i2c_del_adapter(&target->adap); + devm_free_irq(&pdev->dev, target->irq, target); + icc_set_bw(target->icc_path, 0, 0); + clk_disable_unprepare(target->xo_clk); + clk_disable_unprepare(target->ahb_clk); +} + +static int qcom_i2c_target_suspend(struct device *dev) +{ + struct qcom_i2c_target *target = dev_get_drvdata(dev); + int ret; + + disable_irq(target->irq); + writel(0, target->base + I2C_S_IRQ_EN); + writel(0, target->base + I2C_S_CONFIG); + + ret = icc_set_bw(target->icc_path, 0, 0); + if (ret) + dev_err(dev, "icc_set_bw failed on suspend: %d\n", ret); + + clk_disable_unprepare(target->xo_clk); + clk_disable_unprepare(target->ahb_clk); + + return 0; +} + +static int qcom_i2c_target_resume(struct device *dev) +{ + struct qcom_i2c_target *target = dev_get_drvdata(dev); + int ret; + + ret = clk_prepare_enable(target->ahb_clk); + if (ret) { + dev_err(dev, "failed to enable AHB clock\n"); + enable_irq(target->irq); + return ret; + } + + ret = clk_prepare_enable(target->xo_clk); + if (ret) { + dev_err(dev, "failed to enable XO clock\n"); + goto err_disable_ahb; + } + + ret = icc_set_bw(target->icc_path, APPS_PROC_TO_I2C_TARGET_VOTE, + APPS_PROC_TO_I2C_TARGET_VOTE); + if (ret) { + dev_err(dev, "icc_set_bw failed\n"); + goto err_disable_xo; + } + + qcom_i2c_target_hw_init(target); + target->status = 0; + if (target->slave) { + writel(target->slave->addr, target->base + I2C_S_DEVICE_ADDR); + writel(I2C_S_CORE_EN, target->base + I2C_S_CONFIG); + } + + enable_irq(target->irq); + + return 0; + +err_disable_xo: + clk_disable_unprepare(target->xo_clk); +err_disable_ahb: + clk_disable_unprepare(target->ahb_clk); + enable_irq(target->irq); + + return ret; +} + +static const struct dev_pm_ops qcom_i2c_target_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(qcom_i2c_target_suspend, + qcom_i2c_target_resume) +}; + +static const struct of_device_id qcom_i2c_target_dt_match[] = { + { .compatible = "qcom,qdu1000-i2c-target" }, + {} +}; +MODULE_DEVICE_TABLE(of, qcom_i2c_target_dt_match); + +static struct platform_driver qcom_i2c_target_driver = { + .driver = { + .name = "qcom-i2c-target", + .pm = &qcom_i2c_target_pm_ops, + .of_match_table = qcom_i2c_target_dt_match, + }, + .probe = qcom_i2c_target_probe, + .remove = qcom_i2c_target_remove, +}; +module_platform_driver(qcom_i2c_target_driver); + +MODULE_DESCRIPTION("Qualcomm I2C target controller driver"); +MODULE_AUTHOR("Viken Dadhaniya "); +MODULE_LICENSE("GPL"); -- 2.34.1