Hi Jacopo, Excuse for late reply, we were busy in past weeks for major milestone. Please kindly check the revised V7 which has been uploaded. https://patchwork.linuxtv.org/patch/48589/ Responded to your comments as below. Cc in Tomasz for unintentionally missed. Regards, Andy -----Original Message----- From: jacopo mondi [mailto:jacopo@xxxxxxxxxx] Sent: Tuesday, March 20, 2018 6:28 PM To: Yeh, Andy <andy.yeh@xxxxxxxxx> Cc: linux-media@xxxxxxxxxxxxxxx; sakari.ailus@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; Chiang, AlanX <alanx.chiang@xxxxxxxxx> Subject: Re: RESEND[PATCH v6 2/2] media: dw9807: Add dw9807 vcm driver Hi Andy, a few comments on you patch below... On Sat, Mar 17, 2018 at 01:05:26AM +0800, Andy Yeh wrote: > From: Alan Chiang <alanx.chiang@xxxxxxxxx> > > DW9807 is a 10 bit DAC from Dongwoon, designed for linear control of > voice coil motor. > > This driver creates a V4L2 subdevice and provides control to set the > desired focus. > > Signed-off-by: Andy Yeh <andy.yeh@xxxxxxxxx> > --- > since v1: > - changed author. > since v2: > - addressed outstanding comments. > - enabled sequential write to update 2 registers in a single transaction. > since v3: > - addressed comments for v3. > - Remove redundant codes and declare some variables as constant variable. > - separate DT binding to another patch sicne v4: > - sent patchset included DT binding with cover page > > MAINTAINERS | 7 + > drivers/media/i2c/Kconfig | 10 ++ > drivers/media/i2c/Makefile | 1 + > drivers/media/i2c/dw9807.c | 320 > +++++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 338 insertions(+) > create mode 100644 drivers/media/i2c/dw9807.c > > diff --git a/MAINTAINERS b/MAINTAINERS index 845fc25..a339bb5 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -4385,6 +4385,13 @@ T: git git://linuxtv.org/media_tree.git > S: Maintained > F: drivers/media/i2c/dw9714.c > > +DONGWOON DW9807 LENS VOICE COIL DRIVER > +M: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> > +L: linux-media@xxxxxxxxxxxxxxx > +T: git git://linuxtv.org/media_tree.git > +S: Maintained > +F: drivers/media/i2c/dw9807.c > + > DOUBLETALK DRIVER > M: "James R. Van Zandt" <jrv@xxxxxxxxxxxxxxx> > L: blinux-list@xxxxxxxxxx > diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig > index cb5d7ff..fd01842 100644 > --- a/drivers/media/i2c/Kconfig > +++ b/drivers/media/i2c/Kconfig > @@ -325,6 +325,16 @@ config VIDEO_DW9714 > capability. This is designed for linear control of > voice coil motors, controlled via I2C serial interface. > > +config VIDEO_DW9807 > + tristate "DW9807 lens voice coil support" > + depends on I2C && VIDEO_V4L2 && MEDIA_CONTROLLER > + depends on VIDEO_V4L2_SUBDEV_API > + ---help--- > + This is a driver for the DW9807 camera lens voice coil. > + DW9807 is a 10 bit DAC with 100mA output current sink > + capability. This is designed for linear control of > + voice coil motors, controlled via I2C serial interface. > + > config VIDEO_SAA7110 > tristate "Philips SAA7110 video decoder" > depends on VIDEO_V4L2 && I2C > diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile > index 548a9ef..1b62639 100644 > --- a/drivers/media/i2c/Makefile > +++ b/drivers/media/i2c/Makefile > @@ -23,6 +23,7 @@ obj-$(CONFIG_VIDEO_SAA7185) += saa7185.o > obj-$(CONFIG_VIDEO_SAA6752HS) += saa6752hs.o > obj-$(CONFIG_VIDEO_AD5820) += ad5820.o > obj-$(CONFIG_VIDEO_DW9714) += dw9714.o > +obj-$(CONFIG_VIDEO_DW9807) += dw9807.o > obj-$(CONFIG_VIDEO_ADV7170) += adv7170.o > obj-$(CONFIG_VIDEO_ADV7175) += adv7175.o > obj-$(CONFIG_VIDEO_ADV7180) += adv7180.o diff --git > a/drivers/media/i2c/dw9807.c b/drivers/media/i2c/dw9807.c new file > mode 100644 index 0000000..95626e9 > --- /dev/null > +++ b/drivers/media/i2c/dw9807.c > @@ -0,0 +1,320 @@ > +// Copyright (C) 2018 Intel Corporation // SPDX-License-Identifier: > +GPL-2.0 > + > Nit: my understanding is that the SPDX identifier goes first Done > +#include <linux/acpi.h> > +#include <linux/delay.h> > +#include <linux/i2c.h> > +#include <linux/module.h> > +#include <linux/pm_runtime.h> > +#include <media/v4l2-ctrls.h> > +#include <media/v4l2-device.h> > + > +#define DW9807_NAME "dw9807" > +#define DW9807_MAX_FOCUS_POS 1023 > +/* > + * This sets the minimum granularity for the focus positions. > + * A value of 1 gives maximum accuracy for a desired focus position > Please end comments with a full stop, here and in the rest of the driver. Done > + */ > +#define DW9807_FOCUS_STEPS 1 > +/* > + * This acts as the minimum granularity of lens movement. > + * Keep this value power of 2, so the control steps can be > + * uniformly adjusted for gradual lens movement, with desired > + * number of control steps. > + */ > +#define DW9807_CTRL_STEPS 16 > +#define DW9807_CTRL_DELAY_US 1000 > + > +#define DW9807_CTL_ADDR 0x02 > +/* > + * DW9807 separates two registers to control the VCM position. > + * One for MSB value, another is LSB value. > + */ > +#define DW9807_MSB_ADDR 0x03 > +#define DW9807_LSB_ADDR 0x04 > +#define DW9807_STATUS_ADDR 0x05 > +#define DW9807_MODE_ADDR 0x06 > +#define DW9807_RESONANCE_ADDR 0x07 > + > +#define MAX_RETRY 10 > + > +struct dw9807_device { > + struct v4l2_ctrl_handler ctrls_vcm; > + struct v4l2_subdev sd; > + u16 current_val; > +}; > + > +static inline struct dw9807_device *sd_to_dw9807_vcm(struct > +v4l2_subdev *subdev) { > + return container_of(subdev, struct dw9807_device, sd); } > + > +static int dw9807_i2c_check(struct i2c_client *client) { > + const char status_addr = DW9807_STATUS_ADDR; > + char status_result = 0x1; > Do you need to intialize this? This is not necessary, remove it. Done. > + int ret; > + > + ret = i2c_master_send(client, (const char *)&status_addr, sizeof(status_addr)); > + if (ret != sizeof(status_addr)) { > I think ret is either < 0 or the buffer length byte count. > i2c_master_send() calls i2c_transfer_buffer_flags that uses i2c_transfer(). > i2c_transfer returns either an error code, or the number of i2c messages transfered. > i2c_master_send(client, buf, count): > return i2c_transfer_buffer_flags(client, buf, count, 0): > ret = i2c_transfer(adapter, buf, count); > return (ret == 1) ? count : ret; Only check the error code currently. Done. > + dev_err(&client->dev, "I2C write STATUS address fail ret = %d\n", > + ret); > + return -EIO; > please consider returning ret to propagate the i2c error Done > + } > + > + ret = i2c_master_recv(client, (char *)&status_result, sizeof(status_result)); > + if (ret != sizeof(status_result)) { > + dev_err(&client->dev, "I2C read STATUS value fail ret=%d\n", > + ret); > + return -EIO; > + } > same here Done > + > + return status_result; > +} > + > +static int dw9807_set_dac(struct i2c_client *client, u16 data) { > + const char tx_data[3] = { > + DW9807_MSB_ADDR, ((data >> 8) & 0x03), (data & 0xFF) }; > lowercase for hex (0xff). > Also, this is not a general rule, but, could you consider closing the brace on next line? Done > + int ret, retry = 0; > + > + /* > + * According to the datasheet, need to check the bus status before we > + * write VCM position. This ensure that we really write the value > + * into the register > + */ > + while (dw9807_i2c_check(client) != 0) { > Up to you, but with this check, you are ignoring i2c errors Check the i2c error as well. Done. > + if (MAX_RETRY == ++retry) { > + dev_err(&client->dev, "Cannot do the write operation because VCM is busy\n"); > + return -EIO; > + } > + usleep_range(DW9807_CTRL_DELAY_US, DW9807_CTRL_DELAY_US + 10); > + } > + > + /* Write VCM position to registers */ > + ret = i2c_master_send(client, tx_data, sizeof(tx_data)); > + if (ret != sizeof(tx_data)) { > + dev_err(&client->dev, "I2C write MSB fail\n"); > Same as above. Check for < 0 and please printout the error code in the error message (and consider propagating to the caller). Check the i2c error as well. Done. > + return -EIO; > + } > + > + return 0; > +} > + > +static int dw9807_set_ctrl(struct v4l2_ctrl *ctrl) { > + struct dw9807_device *dev_vcm = container_of(ctrl->handler, struct > +dw9807_device, ctrls_vcm); > This seems clearly longer than 80 cols. Have you run checkpatch on this? truncate this line. Done. > + > + if (ctrl->id == V4L2_CID_FOCUS_ABSOLUTE) { > + struct i2c_client *client = v4l2_get_subdevdata(&dev_vcm->sd); > + > + dev_vcm->current_val = ctrl->val; > + return dw9807_set_dac(client, ctrl->val); > + } > + > + return -EINVAL; > +} > + > +static const struct v4l2_ctrl_ops dw9807_vcm_ctrl_ops = { > + .s_ctrl = dw9807_set_ctrl, > +}; > + > +static int dw9807_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh > +*fh) { > + int rval; > + > + rval = pm_runtime_get_sync(sd->dev); > + if (rval < 0) { > + pm_runtime_put_noidle(sd->dev); > If you fail to get pm context, no need to put it back (I presume) According to Sakari Ailus's comment on LinuxTV. (pm_runtime_get() must be followed by pm_runtime_put() whether the former succeeds or not.) So it is no need to modify. > + return rval; > + } > + > + return 0; > +} > + > +static int dw9807_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh > +*fh) { > + pm_runtime_put(sd->dev); > + > + return 0; > +} > + > +static const struct v4l2_subdev_internal_ops dw9807_int_ops = { > + .open = dw9807_open, > + .close = dw9807_close, > +}; > + > +static const struct v4l2_subdev_ops dw9807_ops = { }; > + > +static void dw9807_subdev_cleanup(struct dw9807_device *dw9807_dev) { > + v4l2_async_unregister_subdev(&dw9807_dev->sd); > + v4l2_ctrl_handler_free(&dw9807_dev->ctrls_vcm); > + media_entity_cleanup(&dw9807_dev->sd.entity); > +} > + > +static int dw9807_init_controls(struct dw9807_device *dev_vcm) { > + struct v4l2_ctrl_handler *hdl = &dev_vcm->ctrls_vcm; > + const struct v4l2_ctrl_ops *ops = &dw9807_vcm_ctrl_ops; > + struct i2c_client *client = v4l2_get_subdevdata(&dev_vcm->sd); > + > + v4l2_ctrl_handler_init(hdl, 1); > + > + v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FOCUS_ABSOLUTE, > + 0, DW9807_MAX_FOCUS_POS, DW9807_FOCUS_STEPS, 0); > + > + dev_vcm->sd.ctrl_handler = hdl; > + if (hdl->error) { > + dev_err(&client->dev, "%s fail error: 0x%x\n", > + __func__, hdl->error); > + return hdl->error; > + } > + > + return 0; > +} > + > +static int dw9807_probe(struct i2c_client *client) { > + struct dw9807_device *dw9807_dev; > + int rval; > + > + dw9807_dev = devm_kzalloc(&client->dev, sizeof(*dw9807_dev), > + GFP_KERNEL); > + if (dw9807_dev == NULL) > if (!dw9807) or checkpatch complains Done > + return -ENOMEM; > + > + v4l2_i2c_subdev_init(&dw9807_dev->sd, client, &dw9807_ops); > + dw9807_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE; > + dw9807_dev->sd.internal_ops = &dw9807_int_ops; > + > + rval = dw9807_init_controls(dw9807_dev); > + if (rval) > + goto err_cleanup; > + > + rval = media_entity_pads_init(&dw9807_dev->sd.entity, 0, NULL); > + if (rval < 0) > + goto err_cleanup; > + > + dw9807_dev->sd.entity.function = MEDIA_ENT_F_LENS; > + > + rval = v4l2_async_register_subdev(&dw9807_dev->sd); > + if (rval < 0) > + goto err_cleanup; > + > + pm_runtime_set_active(&client->dev); > + pm_runtime_enable(&client->dev); > + pm_runtime_idle(&client->dev); > + > + return 0; > + > +err_cleanup: > + dw9807_subdev_cleanup(dw9807_dev); > empty line before return maybe? Add a line. Done. > + return rval; > +} > + > +static int dw9807_remove(struct i2c_client *client) { > + struct v4l2_subdev *sd = i2c_get_clientdata(client); > + struct dw9807_device *dw9807_dev = sd_to_dw9807_vcm(sd); > + > + pm_runtime_disable(&client->dev); > + pm_runtime_set_suspended(&client->dev); > + > + dw9807_subdev_cleanup(dw9807_dev); > + > + return 0; > +} > + > +/* > + * This function sets the vcm position, so it consumes least current > + * The lens position is gradually moved in units of > +DW9807_CTRL_STEPS, > + * to make the movements smoothly. > + */ > +static int __maybe_unused dw9807_vcm_suspend(struct device *dev) { > + struct i2c_client *client = to_i2c_client(dev); > + struct v4l2_subdev *sd = i2c_get_clientdata(client); > + struct dw9807_device *dw9807_dev = sd_to_dw9807_vcm(sd); > + const char tx_data[2] = { DW9807_CTL_ADDR, 0x01 }; > + int ret, val; > + > + for (val = dw9807_dev->current_val & ~(DW9807_CTRL_STEPS - 1); > + val >= 0; val -= DW9807_CTRL_STEPS) { > + ret = dw9807_set_dac(client, val); > + if (ret) > + dev_err_once(dev, "%s I2C failure: %d", __func__, ret); > + usleep_range(DW9807_CTRL_DELAY_US, DW9807_CTRL_DELAY_US + 10); > + } > + > + /* Power down */ > + ret = i2c_master_send(client, tx_data, sizeof(tx_data)); > + > + if (ret != sizeof(tx_data)) { > + dev_err(&client->dev, "I2C write CTL fail\n"); > + return -EIO; > + } > + > + return 0; > +} > + > +/* > + * This function sets the vcm position to the value set by the user > + * through v4l2_ctrl_ops s_ctrl handler > + * The lens position is gradually moved in units of > +DW9807_CTRL_STEPS, > + * to make the movements smoothly. > + */ > +static int __maybe_unused dw9807_vcm_resume(struct device *dev) { > + struct i2c_client *client = to_i2c_client(dev); > + struct v4l2_subdev *sd = i2c_get_clientdata(client); > + struct dw9807_device *dw9807_dev = sd_to_dw9807_vcm(sd); > + const char tx_data[2] = { DW9807_CTL_ADDR, 0x00 }; > + int ret, val; > + > + /* Power on */ > + ret = i2c_master_send(client, tx_data, sizeof(tx_data)); > + if (ret != sizeof(tx_data)) { > + dev_err(&client->dev, "I2C write CTL fail\n"); > + return -EIO; > + } > + > + for (val = dw9807_dev->current_val % DW9807_CTRL_STEPS; > + val < dw9807_dev->current_val + DW9807_CTRL_STEPS - 1; > + val += DW9807_CTRL_STEPS) { > + ret = dw9807_set_dac(client, val); > + if (ret) > + dev_err_ratelimited(dev, "%s I2C failure: %d", > + __func__, ret); > + usleep_range(DW9807_CTRL_DELAY_US, DW9807_CTRL_DELAY_US + 10); > + } > + > + return 0; > +} > + > +static const struct of_device_id dw9807_of_table[] = { > + { .compatible = "dongwoon,dw9807" }, > + { { 0 } } > { } is enough. According to Sakari Ailus's comment on LinuxTV. { } is GCC specific while { { 0 } } isn't. And if I remove it, compile error will occur. > +}; > +MODULE_DEVICE_TABLE(of, dw9807_of_table); > + > +static const struct dev_pm_ops dw9807_pm_ops = { > + SET_SYSTEM_SLEEP_PM_OPS(dw9807_vcm_suspend, dw9807_vcm_resume) > + SET_RUNTIME_PM_OPS(dw9807_vcm_suspend, dw9807_vcm_resume, NULL) }; > + > +static struct i2c_driver dw9807_i2c_driver = { > + .driver = { > + .name = DW9807_NAME, > That DW9807_NAME define is used only here. Done > Thanks > j > + .pm = &dw9807_pm_ops, > + .of_match_table = dw9807_of_table, > + }, > + .probe_new = dw9807_probe, > + .remove = dw9807_remove, > +}; > + > +module_i2c_driver(dw9807_i2c_driver); > + > +MODULE_AUTHOR("Chiang, Alan <alanx.chiang@xxxxxxxxx>"); > +MODULE_DESCRIPTION("DW9807 VCM driver"); MODULE_LICENSE("GPL v2"); > -- > 2.7.4 > ��.n��������+%������w��{.n����z�{��ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
