Hi Loic, here are my first comments. Probably not all of them yet, but there are some high level questions I wanted to discuss before diving in too deep. One more general thing, I think the driver has too much dev_err in it. Please keep only the important ones, and turn supplementary ones into dev_dbg. Interested users can then enable them. Thank you for your patience and now for my comments: On Tue, Mar 10, 2020 at 09:46:59AM +0100, Loic Poulain wrote: > This commit adds I2C bus support for the Camera Control Interface > (CCI) I2C controller found on the Qualcomm SoC processors. This I2C > controller supports two masters and they are registered to the core. > > CCI versions supported in the driver are msm8916, msm8996 and sdm845. > > This is a rework of the patch posted by Vinod: > https://patchwork.kernel.org/patch/10569961/ > > With additional fixes + most of the comments addressed. > > Signed-off-by: Todor Tomov > Signed-off-by: Vinod Koul > Signed-off-by: Loic Poulain > Tested-by: Robert Foss > Reviewed-by: Bjorn Andersson > --- > v2: Remove clock rates config from driver (done via assigned clock) > Added CCI timeout recovery from Ricardo's patch: > https://www.spinics.net/lists/linux-i2c/msg36973.html > v3: add sdm845 support > rework cci_init function > v4: fix checkpatch issue (double semi-colo > v5: address Bjorn's comment > Kconfig/Makefile order > probe/interrupt rework > v6: Fix exit path (disable_clocks) > > drivers/i2c/busses/Kconfig | 10 + > drivers/i2c/busses/Makefile | 1 + > drivers/i2c/busses/i2c-qcom-cci.c | 792 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 803 insertions(+) > create mode 100644 drivers/i2c/busses/i2c-qcom-cci.c > > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig > index 6a0aa76..d962671 100644 > --- a/drivers/i2c/busses/Kconfig > +++ b/drivers/i2c/busses/Kconfig > @@ -881,6 +881,16 @@ config I2C_PXA_SLAVE > is necessary for systems where the PXA may be a target on the > I2C bus. > > +config I2C_QCOM_CCI > + tristate "Qualcomm Camera Control Interface" > + depends on ARCH_QCOM || COMPILE_TEST > + help > + If you say yes to this option, support will be included for the > + built-in camera control interface on the Qualcomm SoCs. > + > + This driver can also be built as a module. If so, the module > + will be called i2c-qcom-cci. > + > config I2C_QCOM_GENI > tristate "Qualcomm Technologies Inc.'s GENI based I2C controller" > depends on ARCH_QCOM || COMPILE_TEST > diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile > index 3ab8aeb..d8b0788 100644 > --- a/drivers/i2c/busses/Makefile > +++ b/drivers/i2c/busses/Makefile > @@ -91,6 +91,7 @@ obj-$(CONFIG_I2C_PNX) += i2c-pnx.o > obj-$(CONFIG_I2C_PUV3) += i2c-puv3.o > 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-$(CONFIG_I2C_QUP) += i2c-qup.o > obj-$(CONFIG_I2C_RIIC) += i2c-riic.o > diff --git a/drivers/i2c/busses/i2c-qcom-cci.c b/drivers/i2c/busses/i2c-qcom-cci.c > new file mode 100644 > index 0000000..9378486 > --- /dev/null > +++ b/drivers/i2c/busses/i2c-qcom-cci.c > @@ -0,0 +1,792 @@ > +// SPDX-License-Identifier: GPL-2.0 > +// Copyright (c) 2012-2016, The Linux Foundation. All rights reserved. > +// Copyright (c) 2017-19 Linaro Limited. > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define CCI_HW_VERSION 0x0 > +#define CCI_RESET_CMD 0x004 > +#define CCI_RESET_CMD_MASK 0x0f73f3f7 > +#define CCI_RESET_CMD_M0_MASK 0x000003f1 > +#define CCI_RESET_CMD_M1_MASK 0x0003f001 > +#define CCI_QUEUE_START 0x008 > +#define CCI_HALT_REQ 0x034 > +#define CCI_HALT_REQ_I2C_M0_Q0Q1 BIT(0) > +#define CCI_HALT_REQ_I2C_M1_Q0Q1 BIT(1) > + > +#define CCI_I2C_Mm_SCL_CTL(m) (0x100 + 0x100 * (m)) > +#define CCI_I2C_Mm_SDA_CTL_0(m) (0x104 + 0x100 * (m)) > +#define CCI_I2C_Mm_SDA_CTL_1(m) (0x108 + 0x100 * (m)) > +#define CCI_I2C_Mm_SDA_CTL_2(m) (0x10c + 0x100 * (m)) > +#define CCI_I2C_Mm_MISC_CTL(m) (0x110 + 0x100 * (m)) > + > +#define CCI_I2C_Mm_READ_DATA(m) (0x118 + 0x100 * (m)) > +#define CCI_I2C_Mm_READ_BUF_LEVEL(m) (0x11c + 0x100 * (m)) > +#define CCI_I2C_Mm_Qn_EXEC_WORD_CNT(m, n) (0x300 + 0x200 * (m) + 0x100 * (n)) > +#define CCI_I2C_Mm_Qn_CUR_WORD_CNT(m, n) (0x304 + 0x200 * (m) + 0x100 * (n)) > +#define CCI_I2C_Mm_Qn_CUR_CMD(m, n) (0x308 + 0x200 * (m) + 0x100 * (n)) > +#define CCI_I2C_Mm_Qn_REPORT_STATUS(m, n) (0x30c + 0x200 * (m) + 0x100 * (n)) > +#define CCI_I2C_Mm_Qn_LOAD_DATA(m, n) (0x310 + 0x200 * (m) + 0x100 * (n)) > + > +#define CCI_IRQ_GLOBAL_CLEAR_CMD 0xc00 > +#define CCI_IRQ_MASK_0 0xc04 > +#define CCI_IRQ_MASK_0_I2C_M0_RD_DONE BIT(0) > +#define CCI_IRQ_MASK_0_I2C_M0_Q0_REPORT BIT(4) > +#define CCI_IRQ_MASK_0_I2C_M0_Q1_REPORT BIT(8) > +#define CCI_IRQ_MASK_0_I2C_M1_RD_DONE BIT(12) > +#define CCI_IRQ_MASK_0_I2C_M1_Q0_REPORT BIT(16) > +#define CCI_IRQ_MASK_0_I2C_M1_Q1_REPORT BIT(20) > +#define CCI_IRQ_MASK_0_RST_DONE_ACK BIT(24) > +#define CCI_IRQ_MASK_0_I2C_M0_Q0Q1_HALT_ACK BIT(25) > +#define CCI_IRQ_MASK_0_I2C_M1_Q0Q1_HALT_ACK BIT(26) > +#define CCI_IRQ_MASK_0_I2C_M0_ERROR 0x18000ee6 > +#define CCI_IRQ_MASK_0_I2C_M1_ERROR 0x60ee6000 > +#define CCI_IRQ_CLEAR_0 0xc08 > +#define CCI_IRQ_STATUS_0 0xc0c > +#define CCI_IRQ_STATUS_0_I2C_M0_RD_DONE BIT(0) > +#define CCI_IRQ_STATUS_0_I2C_M0_Q0_REPORT BIT(4) > +#define CCI_IRQ_STATUS_0_I2C_M0_Q1_REPORT BIT(8) > +#define CCI_IRQ_STATUS_0_I2C_M1_RD_DONE BIT(12) > +#define CCI_IRQ_STATUS_0_I2C_M1_Q0_REPORT BIT(16) > +#define CCI_IRQ_STATUS_0_I2C_M1_Q1_REPORT BIT(20) > +#define CCI_IRQ_STATUS_0_RST_DONE_ACK BIT(24) > +#define CCI_IRQ_STATUS_0_I2C_M0_Q0Q1_HALT_ACK BIT(25) > +#define CCI_IRQ_STATUS_0_I2C_M1_Q0Q1_HALT_ACK BIT(26) > +#define CCI_IRQ_STATUS_0_I2C_M0_ERROR 0x18000ee6 > +#define CCI_IRQ_STATUS_0_I2C_M1_ERROR 0x60ee6000 > + > +#define CCI_TIMEOUT (msecs_to_jiffies(100)) > +#define NUM_MASTERS 2 > +#define NUM_QUEUES 2 > + > +/* Max number of resources + 1 for a NULL terminator */ > +#define CCI_RES_MAX 6 > + > +#define CCI_I2C_SET_PARAM 1 > +#define CCI_I2C_REPORT 8 > +#define CCI_I2C_WRITE 9 > +#define CCI_I2C_READ 10 > + > +#define CCI_I2C_REPORT_IRQ_EN BIT(8) > + > +enum { > + I2C_MODE_STANDARD, > + I2C_MODE_FAST, > + I2C_MODE_FAST_PLUS, > +}; > + > +enum cci_i2c_queue_t { > + QUEUE_0, > + QUEUE_1 > +}; > + > +struct hw_params { > + u16 thigh; /* HIGH period of the SCL clock in clock ticks */ > + u16 tlow; /* LOW period of the SCL clock */ > + u16 tsu_sto; /* set-up time for STOP condition */ > + u16 tsu_sta; /* set-up time for a repeated START condition */ > + u16 thd_dat; /* data hold time */ > + u16 thd_sta; /* hold time (repeated) START condition */ > + u16 tbuf; /* bus free time between a STOP and START condition */ > + u8 scl_stretch_en; > + u16 trdhld; > + u16 tsp; /* pulse width of spikes suppressed by the input filter */ > +}; > + > +struct cci; > + > +struct cci_master { > + struct i2c_adapter adap; > + u16 master; > + u8 mode; > + int status; > + struct completion irq_complete; > + struct cci *cci; > +}; > + > +struct cci_data { > + unsigned int num_masters; > + struct i2c_adapter_quirks quirks; > + u16 queue_size[NUM_QUEUES]; > + unsigned long cci_clk_rate; > + struct hw_params params[3]; > +}; > + > +struct cci { > + struct device *dev; > + void __iomem *base; > + unsigned int irq; > + const struct cci_data *data; > + struct clk_bulk_data *clocks; > + int nclocks; > + struct cci_master master[NUM_MASTERS]; > +}; > + > +static irqreturn_t cci_isr(int irq, void *dev) > +{ > + struct cci *cci = dev; > + u32 val, reset = 0; > + int ret = IRQ_NONE; > + > + val = readl(cci->base + CCI_IRQ_STATUS_0); > + writel(val, cci->base + CCI_IRQ_CLEAR_0); > + writel(0x1, cci->base + CCI_IRQ_GLOBAL_CLEAR_CMD); > + > + if (val & CCI_IRQ_STATUS_0_RST_DONE_ACK) { > + complete(&cci->master[0].irq_complete); > + if (cci->master[1].master) > + complete(&cci->master[1].irq_complete); > + ret = IRQ_HANDLED; > + } > + > + if (val & CCI_IRQ_STATUS_0_I2C_M0_RD_DONE || > + val & CCI_IRQ_STATUS_0_I2C_M0_Q0_REPORT || > + val & CCI_IRQ_STATUS_0_I2C_M0_Q1_REPORT) { > + cci->master[0].status = 0; > + complete(&cci->master[0].irq_complete); > + ret = IRQ_HANDLED; > + } > + > + if (val & CCI_IRQ_STATUS_0_I2C_M1_RD_DONE || > + val & CCI_IRQ_STATUS_0_I2C_M1_Q0_REPORT || > + val & CCI_IRQ_STATUS_0_I2C_M1_Q1_REPORT) { > + cci->master[1].status = 0; > + complete(&cci->master[1].irq_complete); > + ret = IRQ_HANDLED; > + } > + > + if (unlikely(val & CCI_IRQ_STATUS_0_I2C_M0_Q0Q1_HALT_ACK)) { > + reset = CCI_RESET_CMD_M0_MASK; > + ret = IRQ_HANDLED; > + } > + > + if (unlikely(val & CCI_IRQ_STATUS_0_I2C_M1_Q0Q1_HALT_ACK)) { > + reset = CCI_RESET_CMD_M1_MASK; > + ret = IRQ_HANDLED; > + } > + > + if (unlikely(reset)) > + writel(reset, cci->base + CCI_RESET_CMD); > + > + if (unlikely(val & CCI_IRQ_STATUS_0_I2C_M0_ERROR)) { > + dev_err_ratelimited(cci->dev, "Master 0 error 0x%08x\n", val); Hmm, using dev_* in an irq handler... > + cci->master[0].status = -EIO; ... isn't it possible to decipher the error bits further and set 'status' according to Documentation/i2c/fault-codes.rst? > + writel(CCI_HALT_REQ_I2C_M0_Q0Q1, cci->base + CCI_HALT_REQ); > + ret = IRQ_HANDLED; > + } > + > + if (unlikely(val & CCI_IRQ_STATUS_0_I2C_M1_ERROR)) { > + dev_err_ratelimited(cci->dev, "Master 1 error 0x%08x\n", val); > + cci->master[1].status = -EIO; > + writel(CCI_HALT_REQ_I2C_M1_Q0Q1, cci->base + CCI_HALT_REQ); > + ret = IRQ_HANDLED; > + } > + > + return ret; > +} > + > +static int cci_halt(struct cci *cci, u8 master_num) > +{ > + struct cci_master *master; > + u32 val; > + > + if (master_num > 1) { Is this hardcoded '1' correct? The loop calling this function iterates up to 'cci->data->num_masters'. > + dev_err(cci->dev, "Unsupported master idx (%u)\n", master_num); > + return -EINVAL; > + } > + > + val = BIT(master_num); > + master = &cci->master[master_num]; > + > + reinit_completion(&master->irq_complete); > + writel(val, cci->base + CCI_HALT_REQ); > + > + if (!wait_for_completion_timeout(&master->irq_complete, CCI_TIMEOUT)) { > + dev_err(cci->dev, "CCI halt timeout\n"); Timeouts can happen on the bus. Please don't print if this is a bus timeout error. > + return -ETIMEDOUT; > + } > + > + return 0; > +} > + > +static int cci_reset(struct cci *cci) > +{ > + /* > + * we reset the whole controller, here and for implicity use > + * master[0].xxx for waiting on it. > + */ > + reinit_completion(&cci->master[0].irq_complete); > + writel(CCI_RESET_CMD_MASK, cci->base + CCI_RESET_CMD); > + > + if (!wait_for_completion_timeout(&cci->master[0].irq_complete, > + CCI_TIMEOUT)) { > + dev_err(cci->dev, "CCI reset timeout\n"); > + return -ETIMEDOUT; > + } > + > + return 0; > +} > + > +static int cci_init(struct cci *cci) > +{ > + u32 val = CCI_IRQ_MASK_0_I2C_M0_RD_DONE | > + CCI_IRQ_MASK_0_I2C_M0_Q0_REPORT | > + CCI_IRQ_MASK_0_I2C_M0_Q1_REPORT | > + CCI_IRQ_MASK_0_I2C_M1_RD_DONE | > + CCI_IRQ_MASK_0_I2C_M1_Q0_REPORT | > + CCI_IRQ_MASK_0_I2C_M1_Q1_REPORT | > + CCI_IRQ_MASK_0_RST_DONE_ACK | > + CCI_IRQ_MASK_0_I2C_M0_Q0Q1_HALT_ACK | > + CCI_IRQ_MASK_0_I2C_M1_Q0Q1_HALT_ACK | > + CCI_IRQ_MASK_0_I2C_M0_ERROR | > + CCI_IRQ_MASK_0_I2C_M1_ERROR; > + int i; > + > + writel(val, cci->base + CCI_IRQ_MASK_0); > + > + for (i = 0; i < cci->data->num_masters; i++) { > + int mode = cci->master[i].mode; > + const struct hw_params *hw; > + > + if (!cci->master[i].cci) > + continue; > + > + hw = &cci->data->params[mode]; > + > + val = hw->thigh << 16 | hw->tlow; > + writel(val, cci->base + CCI_I2C_Mm_SCL_CTL(i)); > + > + val = hw->tsu_sto << 16 | hw->tsu_sta; > + writel(val, cci->base + CCI_I2C_Mm_SDA_CTL_0(i)); > + > + val = hw->thd_dat << 16 | hw->thd_sta; > + writel(val, cci->base + CCI_I2C_Mm_SDA_CTL_1(i)); > + > + val = hw->tbuf; > + writel(val, cci->base + CCI_I2C_Mm_SDA_CTL_2(i)); > + > + val = hw->scl_stretch_en << 8 | hw->trdhld << 4 | hw->tsp; > + writel(val, cci->base + CCI_I2C_Mm_MISC_CTL(i)); > + } > + > + return 0; > +} > + > +static int cci_run_queue(struct cci *cci, u8 master, u8 queue) > +{ > + u32 val; > + int ret; > + > + val = readl(cci->base + CCI_I2C_Mm_Qn_CUR_WORD_CNT(master, queue)); > + writel(val, cci->base + CCI_I2C_Mm_Qn_EXEC_WORD_CNT(master, queue)); > + > + reinit_completion(&cci->master[master].irq_complete); > + val = BIT(master * 2 + queue); > + writel(val, cci->base + CCI_QUEUE_START); > + > + if (!wait_for_completion_timeout(&cci->master[master].irq_complete, > + CCI_TIMEOUT)) { > + dev_err(cci->dev, "master %d queue %d timeout\n", > + master, queue); > + cci_reset(cci); > + cci_init(cci); > + return -ETIMEDOUT; > + } > + > + ret = cci->master[master].status; > + if (ret < 0) > + dev_err(cci->dev, "master %d queue %d error %d\n", > + master, queue, ret); > + > + return ret; > +} > + > +static int cci_validate_queue(struct cci *cci, u8 master, u8 queue) > +{ > + u32 val; > + > + val = readl(cci->base + CCI_I2C_Mm_Qn_CUR_WORD_CNT(master, queue)); > + if (val == cci->data->queue_size[queue]) > + return -EINVAL; > + > + if (!val) > + return 0; > + > + val = CCI_I2C_REPORT | CCI_I2C_REPORT_IRQ_EN; > + writel(val, cci->base + CCI_I2C_Mm_Qn_LOAD_DATA(master, queue)); > + > + return cci_run_queue(cci, master, queue); > +} > + > +static int cci_i2c_read(struct cci *cci, u16 master, > + u16 addr, u8 *buf, u16 len) > +{ > + u32 val, words_read, words_exp; > + u8 queue = QUEUE_1; > + int i, index = 0, ret; > + bool first = true; > + > + /* > + * Call validate queue to make sure queue is empty before starting. > + * This is to avoid overflow / underflow of queue. > + */ > + ret = cci_validate_queue(cci, master, queue); > + if (ret < 0) > + return ret; > + > + val = CCI_I2C_SET_PARAM | (addr & 0x7f) << 4; > + writel(val, cci->base + CCI_I2C_Mm_Qn_LOAD_DATA(master, queue)); > + > + val = CCI_I2C_READ | len << 4; > + writel(val, cci->base + CCI_I2C_Mm_Qn_LOAD_DATA(master, queue)); > + > + ret = cci_run_queue(cci, master, queue); > + if (ret < 0) > + return ret; > + > + words_read = readl(cci->base + CCI_I2C_Mm_READ_BUF_LEVEL(master)); > + words_exp = len / 4 + 1; > + if (words_read != words_exp) { > + dev_err(cci->dev, "words read = %d, words expected = %d\n", > + words_read, words_exp); > + return -EIO; > + } > + > + do { > + val = readl(cci->base + CCI_I2C_Mm_READ_DATA(master)); > + > + for (i = 0; i < 4 && index < len; i++) { > + if (first) { > + /* The LS byte of this register represents the > + * first byte read from the slave during a read > + * access. > + */ > + first = false; > + continue; > + } > + buf[index++] = (val >> (i * 8)) & 0xff; > + } > + } while (--words_read); > + > + return 0; > +} > + > +static int cci_i2c_write(struct cci *cci, u16 master, > + u16 addr, u8 *buf, u16 len) > +{ > + u8 queue = QUEUE_0; > + u8 load[12] = { 0 }; > + int i = 0, j, ret; > + u32 val; > + > + /* > + * Call validate queue to make sure queue is empty before starting. > + * This is to avoid overflow / underflow of queue. > + */ > + ret = cci_validate_queue(cci, master, queue); > + if (ret < 0) > + return ret; > + > + val = CCI_I2C_SET_PARAM | (addr & 0x7f) << 4; > + writel(val, cci->base + CCI_I2C_Mm_Qn_LOAD_DATA(master, queue)); > + > + load[i++] = CCI_I2C_WRITE | len << 4; > + > + for (j = 0; j < len; j++) > + load[i++] = buf[j]; > + > + for (j = 0; j < i; j += 4) { > + val = load[j]; > + val |= load[j + 1] << 8; > + val |= load[j + 2] << 16; > + val |= load[j + 3] << 24; > + writel(val, cci->base + CCI_I2C_Mm_Qn_LOAD_DATA(master, queue)); > + } > + > + val = CCI_I2C_REPORT | CCI_I2C_REPORT_IRQ_EN; > + writel(val, cci->base + CCI_I2C_Mm_Qn_LOAD_DATA(master, queue)); > + > + return cci_run_queue(cci, master, queue); > +} > + > +static int cci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) > +{ > + struct cci_master *cci_master = i2c_get_adapdata(adap); > + struct cci *cci = cci_master->cci; > + int i, ret; > + > + ret = pm_runtime_get_sync(cci->dev); > + if (ret < 0) > + goto err; > + > + for (i = 0; i < num; i++) { > + if (msgs[i].flags & I2C_M_RD) > + ret = cci_i2c_read(cci, cci_master->master, > + msgs[i].addr, msgs[i].buf, > + msgs[i].len); > + else > + ret = cci_i2c_write(cci, cci_master->master, > + msgs[i].addr, msgs[i].buf, > + msgs[i].len); > + > + if (ret < 0) > + break; > + } > + > + if (!ret) > + ret = num; > + > +err: > + pm_runtime_mark_last_busy(cci->dev); > + pm_runtime_put_autosuspend(cci->dev); > + > + return ret; > +} > + > +static u32 cci_func(struct i2c_adapter *adap) > +{ > + return I2C_FUNC_I2C; > +} Even with the quirks, I think this HW is able to support I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA via the I2C core SMBus emulation code. > + > +static const struct i2c_algorithm cci_algo = { > + .master_xfer = cci_xfer, > + .functionality = cci_func, > +}; > + > +static int cci_enable_clocks(struct cci *cci) > +{ > + return clk_bulk_prepare_enable(cci->nclocks, cci->clocks); > +} > + > +static void cci_disable_clocks(struct cci *cci) > +{ > + clk_bulk_disable_unprepare(cci->nclocks, cci->clocks); > +} > + > +static int __maybe_unused cci_suspend_runtime(struct device *dev) > +{ > + struct cci *cci = dev_get_drvdata(dev); > + > + dev_dbg(dev, "Supend invoked\n"); This and the next dev_dbg should go, the PM cores should have printouts for that. > + cci_disable_clocks(cci); > + return 0; > +} > + > +static int __maybe_unused cci_resume_runtime(struct device *dev) > +{ > + struct cci *cci = dev_get_drvdata(dev); > + int ret; > + > + dev_dbg(dev, "Resume invoked\n"); > + ret = cci_enable_clocks(cci); > + if (ret) > + return ret; > + > + cci_init(cci); > + return 0; > +} > + > +static int __maybe_unused cci_suspend(struct device *dev) > +{ > + if (!pm_runtime_suspended(dev)) > + return cci_suspend_runtime(dev); > + > + return 0; > +} > + > +static int __maybe_unused cci_resume(struct device *dev) > +{ > + cci_resume_runtime(dev); > + pm_runtime_mark_last_busy(dev); > + pm_request_autosuspend(dev); > + > + return 0; > +} > + > +static const struct dev_pm_ops qcom_cci_pm = { > + SET_SYSTEM_SLEEP_PM_OPS(cci_suspend, cci_resume) > + SET_RUNTIME_PM_OPS(cci_suspend_runtime, cci_resume_runtime, NULL) > +}; > + > +static int cci_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + unsigned long cci_clk_rate = 0; > + struct device_node *child; > + struct resource *r; > + struct cci *cci; > + int ret, i; > + u32 val; > + > + cci = devm_kzalloc(dev, sizeof(*cci), GFP_KERNEL); > + if (!cci) > + return -ENOMEM; > + > + cci->dev = dev; > + platform_set_drvdata(pdev, cci); > + cci->data = device_get_match_data(dev); > + if (!cci->data) { > + dev_err(dev, "Driver data is null, abort\n"); > + return -EIO; Minor nit: I think this happens only during development, so I'd think returning something like -ENOENT is distinguishable enough to drop the error message. > + } > + > + for_each_available_child_of_node(dev->of_node, child) { > + u32 idx; > + > + ret = of_property_read_u32(child, "reg", &idx); > + if (ret) { > + dev_err(dev, "%pOF invalid 'reg' property", child); > + continue; > + } > + > + if (idx >= cci->data->num_masters) { > + dev_err(dev, "%pOF invalid 'reg' value: %u (max is %u)", > + child, idx, cci->data->num_masters - 1); > + continue; > + } > + > + cci->master[idx].adap.quirks = &cci->data->quirks; > + cci->master[idx].adap.algo = &cci_algo; > + cci->master[idx].adap.dev.parent = dev; > + cci->master[idx].adap.dev.of_node = child; > + cci->master[idx].master = idx; > + cci->master[idx].cci = cci; > + > + i2c_set_adapdata(&cci->master[idx].adap, &cci->master[idx]); > + snprintf(cci->master[idx].adap.name, > + sizeof(cci->master[idx].adap.name), > + "Qualcomm Camera Control Interface: %d", idx); With I2C_NAME_SIZE being 20, I don't think this will work. Did you verify? > + > + cci->master[idx].mode = I2C_MODE_STANDARD; > + ret = of_property_read_u32(child, "clock-frequency", &val); > + if (!ret) { > + if (val == 400000) > + cci->master[idx].mode = I2C_MODE_FAST; > + else if (val == 1000000) > + cci->master[idx].mode = I2C_MODE_FAST_PLUS; > + } > + > + init_completion(&cci->master[idx].irq_complete); > + } > + > + /* Memory */ > + > + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + cci->base = devm_ioremap_resource(dev, r); > + if (IS_ERR(cci->base)) > + return PTR_ERR(cci->base); > + > + /* Clocks */ > + > + ret = devm_clk_bulk_get_all(dev, &cci->clocks); > + if (ret < 1) { > + dev_err(dev, "failed to get clocks %d\n", ret); > + return ret; > + } > + cci->nclocks = ret; > + > + /* Retrieve CCI clock rate */ > + for (i = 0; i < cci->nclocks; i++) { > + if (!strcmp(cci->clocks[i].id, "cci")) { > + cci_clk_rate = clk_get_rate(cci->clocks[i].clk); > + break; > + } > + } > + > + if (cci_clk_rate != cci->data->cci_clk_rate) { > + /* cci clock set by the bootloader or via assigned clock rate > + * in DT. > + */ > + dev_warn(dev, "Found %lu cci clk rate while %lu was expected\n", > + cci_clk_rate, cci->data->cci_clk_rate); > + } > + > + ret = cci_enable_clocks(cci); > + if (ret < 0) > + return ret; > + > + /* Interrupt */ > + > + ret = platform_get_irq(pdev, 0); > + if (ret < 0) { > + dev_err(dev, "missing IRQ: %d\n", ret); > + goto disable_clocks; > + } > + cci->irq = ret; > + > + ret = devm_request_irq(dev, cci->irq, cci_isr, 0, dev_name(dev), cci); > + if (ret < 0) { > + dev_err(dev, "request_irq failed, ret: %d\n", ret); > + goto disable_clocks; > + } > + > + val = readl(cci->base + CCI_HW_VERSION); > + dev_dbg(dev, "CCI HW version = 0x%08x", val); > + > + ret = cci_reset(cci); > + if (ret < 0) > + goto error; > + > + ret = cci_init(cci); > + if (ret < 0) > + goto error; > + > + for (i = 0; i < cci->data->num_masters; i++) { > + if (!cci->master[i].cci) > + continue; > + > + ret = i2c_add_adapter(&cci->master[i].adap); > + if (ret < 0) > + goto error_i2c; > + } > + > + pm_runtime_set_autosuspend_delay(dev, MSEC_PER_SEC); > + pm_runtime_use_autosuspend(dev); > + pm_runtime_set_active(dev); > + pm_runtime_enable(dev); > + > + return 0; > + > +error_i2c: > + for (; i >= 0; i--) { > + if (cci->master[i].cci) > + i2c_del_adapter(&cci->master[i].adap); > + } > +error: > + disable_irq(cci->irq); > +disable_clocks: > + cci_disable_clocks(cci); > + > + return ret; > +} > + > +static int cci_remove(struct platform_device *pdev) > +{ > + struct cci *cci = platform_get_drvdata(pdev); > + int i; > + > + for (i = 0; i < cci->data->num_masters; i++) { > + if (cci->master[i].cci) > + i2c_del_adapter(&cci->master[i].adap); > + cci_halt(cci, i); > + } > + > + disable_irq(cci->irq); > + pm_runtime_disable(&pdev->dev); > + pm_runtime_set_suspended(&pdev->dev); > + > + return 0; > +} > + > +static const struct cci_data cci_v1_data = { > + .num_masters = 1, > + .queue_size = { 64, 16 }, > + .quirks = { > + .max_write_len = 10, > + .max_read_len = 12, > + }, > + .cci_clk_rate = 19200000, > + .params[I2C_MODE_STANDARD] = { > + .thigh = 78, > + .tlow = 114, > + .tsu_sto = 28, > + .tsu_sta = 28, > + .thd_dat = 10, > + .thd_sta = 77, > + .tbuf = 118, > + .scl_stretch_en = 0, > + .trdhld = 6, > + .tsp = 1 > + }, > + .params[I2C_MODE_FAST] = { > + .thigh = 20, > + .tlow = 28, > + .tsu_sto = 21, > + .tsu_sta = 21, > + .thd_dat = 13, > + .thd_sta = 18, > + .tbuf = 32, > + .scl_stretch_en = 0, > + .trdhld = 6, > + .tsp = 3 > + }, > +}; > + > +static const struct cci_data cci_v2_data = { > + .num_masters = 2, > + .queue_size = { 64, 16 }, > + .quirks = { > + .max_write_len = 11, > + .max_read_len = 12, > + }, > + .cci_clk_rate = 37500000, > + .params[I2C_MODE_STANDARD] = { > + .thigh = 201, > + .tlow = 174, > + .tsu_sto = 204, > + .tsu_sta = 231, > + .thd_dat = 22, > + .thd_sta = 162, > + .tbuf = 227, > + .scl_stretch_en = 0, > + .trdhld = 6, > + .tsp = 3 > + }, > + .params[I2C_MODE_FAST] = { > + .thigh = 38, > + .tlow = 56, > + .tsu_sto = 40, > + .tsu_sta = 40, > + .thd_dat = 22, > + .thd_sta = 35, > + .tbuf = 62, > + .scl_stretch_en = 0, > + .trdhld = 6, > + .tsp = 3 > + }, > + .params[I2C_MODE_FAST_PLUS] = { > + .thigh = 16, > + .tlow = 22, > + .tsu_sto = 17, > + .tsu_sta = 18, > + .thd_dat = 16, > + .thd_sta = 15, > + .tbuf = 24, > + .scl_stretch_en = 0, > + .trdhld = 3, > + .tsp = 3 > + }, > +}; These params, can't they be calculated to allow for other frequencies than 100kHz, 400kHz,...? > + > +static const struct of_device_id cci_dt_match[] = { > + { .compatible = "qcom,msm8916-cci", .data = &cci_v1_data}, > + { .compatible = "qcom,msm8996-cci", .data = &cci_v2_data}, > + { .compatible = "qcom,sdm845-cci", .data = &cci_v2_data}, > + {} > +}; > +MODULE_DEVICE_TABLE(of, cci_dt_match); > + > +static struct platform_driver qcom_cci_driver = { > + .probe = cci_probe, > + .remove = cci_remove, > + .driver = { > + .name = "i2c-qcom-cci", > + .of_match_table = cci_dt_match, > + .pm = &qcom_cci_pm, > + }, > +}; > + > +module_platform_driver(qcom_cci_driver); > + > +MODULE_DESCRIPTION("Qualcomm Camera Control Interface driver"); > +MODULE_AUTHOR("Todor Tomov "); > +MODULE_AUTHOR("Loic Poulain "); > +MODULE_LICENSE("GPL v2"); > -- > 2.7.4 >