| Message ID | 20210827211258.318618-2-marex@denx.de |
|---|---|
| State | New |
| Headers | show |
| Series | [v2,1/3] Input: ili210x - use resolution from ili251x firmware | expand |
On Fri, Aug 27, 2021 at 11:12:57PM +0200, Marek Vasut wrote: > The ili251x firmware protocol permits readout of firmware version, > protocol version, mcu version and current mode (application, boot > loader, forced update). These information are useful when updating > the firmware on the il251x, e.g. to avoid updating the same firmware > into the device multiple times. The locking is now necessary to avoid > races between interrupt handler and the sysfs readouts. > > Note that the protocol differs considerably between the ili2xxx devices, > this patch therefore implements this functionality only for ili251x that > I can test. > > Signed-off-by: Marek Vasut <marex@denx.de> > Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> > Cc: Joe Hung <joe_hung@ilitek.com> > Cc: Luca Hsu <luca_hsu@ilitek.com> > --- > V2: No change > > NOTE: Regarding checkpatch warnings, Consider renaming function(s) > 'ili251x_firmware_version_show' to 'firmware_version_show', > I considered it and decided against it, because grepping for > ili251x in debug symbols gives far more accurate results than > grepping for firmware_version. Yep, I completely agree here. I wish checkpatch did not complain about this. > --- > drivers/input/touchscreen/ili210x.c | 130 +++++++++++++++++++++++++++- > 1 file changed, 127 insertions(+), 3 deletions(-) > > diff --git a/drivers/input/touchscreen/ili210x.c b/drivers/input/touchscreen/ili210x.c > index c46553ecabe6..7790ad000dc1 100644 > --- a/drivers/input/touchscreen/ili210x.c > +++ b/drivers/input/touchscreen/ili210x.c > @@ -22,6 +22,12 @@ > /* Touchscreen commands */ > #define REG_TOUCHDATA 0x10 > #define REG_PANEL_INFO 0x20 > +#define REG_FIRMWARE_VERSION 0x40 > +#define REG_PROTOCOL_VERSION 0x42 > +#define REG_KERNEL_VERSION 0x61 > +#define REG_IC_MODE 0xc0 > +#define REG_IC_MODE_AP 0x5a > +#define REG_IC_MODE_BL 0x55 > #define REG_CALIBRATE 0xcc > > struct ili2xxx_chip { > @@ -43,6 +49,7 @@ struct ili210x { > struct input_dev *input; > struct gpio_desc *reset_gpio; > struct touchscreen_properties prop; > + struct mutex lock; > const struct ili2xxx_chip *chip; > bool stop; > }; > @@ -307,7 +314,9 @@ static irqreturn_t ili210x_irq(int irq, void *irq_data) > int error; > > do { > + mutex_lock(&priv->lock); > error = chip->get_touch_data(client, touchdata); > + mutex_unlock(&priv->lock); > if (error) { > dev_err(&client->dev, > "Unable to get touch data: %d\n", error); > @@ -351,6 +360,108 @@ static int ili251x_firmware_update_resolution(struct device *dev) > return 0; > } > > +static ssize_t ili251x_firmware_version_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + struct i2c_client *client = to_i2c_client(dev); > + struct ili210x *priv = i2c_get_clientdata(client); > + u8 fw[8]; > + int ret; > + > + /* Get firmware version */ > + mutex_lock(&priv->lock); > + ret = priv->chip->read_reg(client, REG_FIRMWARE_VERSION, > + &fw, sizeof(fw)); > + mutex_unlock(&priv->lock); Could we query firmware version and mode at probe time (and also later after firmware update attempt) so that we do not need to introduce locking against interrupt handler? > + > + if (ret) > + return ret; > + > + if (!ret) { > + ret = scnprintf(buf, PAGE_SIZE, > + "%02x%02x.%02x%02x.%02x%02x.%02x%02x\n", > + fw[0], fw[1], fw[2], fw[3], > + fw[4], fw[5], fw[6], fw[7]); > + } I think there is sysfs_emit() that is preferred now. Thanks. -- Dmitry
On 8/30/21 11:01 PM, Dmitry Torokhov wrote: [...] >> @@ -351,6 +360,108 @@ static int ili251x_firmware_update_resolution(struct device *dev) >> return 0; >> } >> >> +static ssize_t ili251x_firmware_version_show(struct device *dev, >> + struct device_attribute *attr, >> + char *buf) >> +{ >> + struct i2c_client *client = to_i2c_client(dev); >> + struct ili210x *priv = i2c_get_clientdata(client); >> + u8 fw[8]; >> + int ret; >> + >> + /* Get firmware version */ >> + mutex_lock(&priv->lock); >> + ret = priv->chip->read_reg(client, REG_FIRMWARE_VERSION, >> + &fw, sizeof(fw)); >> + mutex_unlock(&priv->lock); > > Could we query firmware version and mode at probe time (and also later > after firmware update attempt) so that we do not need to introduce > locking against interrupt handler? This is a threaded interrupt handler and I don't expect much lock contention here. The sysfs attribute readout would race with the interrupt handler and if it wasn't for the firmware update support, we could very well cache all those values. Except, the firmware update can change them all. Worse, if the interrupt were to fire during an update, it could break that update, and I want to prevent that from happening. [...]
On Tue, Aug 31, 2021 at 01:02:57AM +0200, Marek Vasut wrote: > On 8/30/21 11:01 PM, Dmitry Torokhov wrote: > > [...] > > > > @@ -351,6 +360,108 @@ static int ili251x_firmware_update_resolution(struct device *dev) > > > return 0; > > > } > > > +static ssize_t ili251x_firmware_version_show(struct device *dev, > > > + struct device_attribute *attr, > > > + char *buf) > > > +{ > > > + struct i2c_client *client = to_i2c_client(dev); > > > + struct ili210x *priv = i2c_get_clientdata(client); > > > + u8 fw[8]; > > > + int ret; > > > + > > > + /* Get firmware version */ > > > + mutex_lock(&priv->lock); > > > + ret = priv->chip->read_reg(client, REG_FIRMWARE_VERSION, > > > + &fw, sizeof(fw)); > > > + mutex_unlock(&priv->lock); > > > > Could we query firmware version and mode at probe time (and also later > > after firmware update attempt) so that we do not need to introduce > > locking against interrupt handler? > > This is a threaded interrupt handler and I don't expect much lock contention > here. > > The sysfs attribute readout would race with the interrupt handler and if it > wasn't for the firmware update support, we could very well cache all those > values. Except, the firmware update can change them all. Worse, if the > interrupt were to fire during an update, it could break that update, and I > want to prevent that from happening. Usually we simply disable interrupts from the device when updating firmware. Thanks. -- Dmitry
On 8/31/21 1:20 AM, Dmitry Torokhov wrote: > On Tue, Aug 31, 2021 at 01:02:57AM +0200, Marek Vasut wrote: >> On 8/30/21 11:01 PM, Dmitry Torokhov wrote: >> >> [...] >> >>>> @@ -351,6 +360,108 @@ static int ili251x_firmware_update_resolution(struct device *dev) >>>> return 0; >>>> } >>>> +static ssize_t ili251x_firmware_version_show(struct device *dev, >>>> + struct device_attribute *attr, >>>> + char *buf) >>>> +{ >>>> + struct i2c_client *client = to_i2c_client(dev); >>>> + struct ili210x *priv = i2c_get_clientdata(client); >>>> + u8 fw[8]; >>>> + int ret; >>>> + >>>> + /* Get firmware version */ >>>> + mutex_lock(&priv->lock); >>>> + ret = priv->chip->read_reg(client, REG_FIRMWARE_VERSION, >>>> + &fw, sizeof(fw)); >>>> + mutex_unlock(&priv->lock); >>> >>> Could we query firmware version and mode at probe time (and also later >>> after firmware update attempt) so that we do not need to introduce >>> locking against interrupt handler? >> >> This is a threaded interrupt handler and I don't expect much lock contention >> here. >> >> The sysfs attribute readout would race with the interrupt handler and if it >> wasn't for the firmware update support, we could very well cache all those >> values. Except, the firmware update can change them all. Worse, if the >> interrupt were to fire during an update, it could break that update, and I >> want to prevent that from happening. > > Usually we simply disable interrupts from the device when updating > firmware. I don't think this touch controller has any "disable interrupts" bit. So the only option here would be some disable_irq() on the IRQ line itself ?
On Tue, Aug 31, 2021 at 01:33:10AM +0200, Marek Vasut wrote: > On 8/31/21 1:20 AM, Dmitry Torokhov wrote: > > On Tue, Aug 31, 2021 at 01:02:57AM +0200, Marek Vasut wrote: > > > On 8/30/21 11:01 PM, Dmitry Torokhov wrote: > > > > > > [...] > > > > > > > > @@ -351,6 +360,108 @@ static int ili251x_firmware_update_resolution(struct device *dev) > > > > > return 0; > > > > > } > > > > > +static ssize_t ili251x_firmware_version_show(struct device *dev, > > > > > + struct device_attribute *attr, > > > > > + char *buf) > > > > > +{ > > > > > + struct i2c_client *client = to_i2c_client(dev); > > > > > + struct ili210x *priv = i2c_get_clientdata(client); > > > > > + u8 fw[8]; > > > > > + int ret; > > > > > + > > > > > + /* Get firmware version */ > > > > > + mutex_lock(&priv->lock); > > > > > + ret = priv->chip->read_reg(client, REG_FIRMWARE_VERSION, > > > > > + &fw, sizeof(fw)); > > > > > + mutex_unlock(&priv->lock); > > > > > > > > Could we query firmware version and mode at probe time (and also later > > > > after firmware update attempt) so that we do not need to introduce > > > > locking against interrupt handler? > > > > > > This is a threaded interrupt handler and I don't expect much lock contention > > > here. > > > > > > The sysfs attribute readout would race with the interrupt handler and if it > > > wasn't for the firmware update support, we could very well cache all those > > > values. Except, the firmware update can change them all. Worse, if the > > > interrupt were to fire during an update, it could break that update, and I > > > want to prevent that from happening. > > > > Usually we simply disable interrupts from the device when updating > > firmware. > > I don't think this touch controller has any "disable interrupts" bit. > So the only option here would be some disable_irq() on the IRQ line itself ? Yes I believe so. -- Dmitry
diff --git a/drivers/input/touchscreen/ili210x.c b/drivers/input/touchscreen/ili210x.c index c46553ecabe6..7790ad000dc1 100644 --- a/drivers/input/touchscreen/ili210x.c +++ b/drivers/input/touchscreen/ili210x.c @@ -22,6 +22,12 @@ /* Touchscreen commands */ #define REG_TOUCHDATA 0x10 #define REG_PANEL_INFO 0x20 +#define REG_FIRMWARE_VERSION 0x40 +#define REG_PROTOCOL_VERSION 0x42 +#define REG_KERNEL_VERSION 0x61 +#define REG_IC_MODE 0xc0 +#define REG_IC_MODE_AP 0x5a +#define REG_IC_MODE_BL 0x55 #define REG_CALIBRATE 0xcc struct ili2xxx_chip { @@ -43,6 +49,7 @@ struct ili210x { struct input_dev *input; struct gpio_desc *reset_gpio; struct touchscreen_properties prop; + struct mutex lock; const struct ili2xxx_chip *chip; bool stop; }; @@ -307,7 +314,9 @@ static irqreturn_t ili210x_irq(int irq, void *irq_data) int error; do { + mutex_lock(&priv->lock); error = chip->get_touch_data(client, touchdata); + mutex_unlock(&priv->lock); if (error) { dev_err(&client->dev, "Unable to get touch data: %d\n", error); @@ -351,6 +360,108 @@ static int ili251x_firmware_update_resolution(struct device *dev) return 0; } +static ssize_t ili251x_firmware_version_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct i2c_client *client = to_i2c_client(dev); + struct ili210x *priv = i2c_get_clientdata(client); + u8 fw[8]; + int ret; + + /* Get firmware version */ + mutex_lock(&priv->lock); + ret = priv->chip->read_reg(client, REG_FIRMWARE_VERSION, + &fw, sizeof(fw)); + mutex_unlock(&priv->lock); + + if (ret) + return ret; + + if (!ret) { + ret = scnprintf(buf, PAGE_SIZE, + "%02x%02x.%02x%02x.%02x%02x.%02x%02x\n", + fw[0], fw[1], fw[2], fw[3], + fw[4], fw[5], fw[6], fw[7]); + } + + return ret; +} +static DEVICE_ATTR(firmware_version, 0444, ili251x_firmware_version_show, NULL); + +static ssize_t ili251x_kernel_version_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct i2c_client *client = to_i2c_client(dev); + struct ili210x *priv = i2c_get_clientdata(client); + u8 kv[5]; + int ret; + + /* Get kernel version */ + mutex_lock(&priv->lock); + ret = priv->chip->read_reg(client, REG_KERNEL_VERSION, + &kv, sizeof(kv)); + mutex_unlock(&priv->lock); + + if (ret) + return ret; + + return scnprintf(buf, PAGE_SIZE, "%02x.%02x.%02x.%02x.%02x\n", + kv[0], kv[1], kv[2], kv[3], kv[4]); +} +static DEVICE_ATTR(kernel_version, 0444, ili251x_kernel_version_show, NULL); + +static ssize_t ili251x_protocol_version_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct i2c_client *client = to_i2c_client(dev); + struct ili210x *priv = i2c_get_clientdata(client); + u8 pv[2]; + int ret; + + /* Get protocol version */ + mutex_lock(&priv->lock); + ret = priv->chip->read_reg(client, REG_PROTOCOL_VERSION, + &pv, sizeof(pv)); + mutex_unlock(&priv->lock); + + if (ret) + return ret; + + return scnprintf(buf, PAGE_SIZE, "%02x.%02x\n", pv[0], pv[1]); +} +static DEVICE_ATTR(protocol_version, 0444, ili251x_protocol_version_show, NULL); + +static ssize_t ili251x_mode_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct i2c_client *client = to_i2c_client(dev); + struct ili210x *priv = i2c_get_clientdata(client); + char *mode = "AP"; + u8 md[2]; + int ret; + + /* Get mode */ + mutex_lock(&priv->lock); + ret = priv->chip->read_reg(client, REG_IC_MODE, &md, sizeof(md)); + mutex_unlock(&priv->lock); + + if (ret) + return ret; + + if (md[0] == REG_IC_MODE_AP) /* Application Mode */ + mode = "AP"; + else if (md[0] == REG_IC_MODE_BL) /* BootLoader Mode */ + mode = "BL"; + else /* Unknown Mode */ + mode = "??"; + + return scnprintf(buf, PAGE_SIZE, "%02x.%02x:%s\n", md[0], md[1], mode); +} +static DEVICE_ATTR(mode, 0444, ili251x_mode_show, NULL); + static ssize_t ili210x_calibrate(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) @@ -379,22 +490,34 @@ static DEVICE_ATTR(calibrate, S_IWUSR, NULL, ili210x_calibrate); static struct attribute *ili210x_attributes[] = { &dev_attr_calibrate.attr, + &dev_attr_firmware_version.attr, + &dev_attr_kernel_version.attr, + &dev_attr_protocol_version.attr, + &dev_attr_mode.attr, NULL, }; -static umode_t ili210x_calibrate_visible(struct kobject *kobj, +static umode_t ili210x_attributes_visible(struct kobject *kobj, struct attribute *attr, int index) { struct device *dev = kobj_to_dev(kobj); struct i2c_client *client = to_i2c_client(dev); struct ili210x *priv = i2c_get_clientdata(client); - return priv->chip->has_calibrate_reg ? attr->mode : 0; + /* Calibrate is present on all ILI2xxx which have calibrate register */ + if (attr == &dev_attr_calibrate.attr) + return priv->chip->has_calibrate_reg ? attr->mode : 0; + + /* Firmware/Kernel/Protocol/BootMode is implememted only for ILI251x */ + if (priv->chip != &ili251x_chip) + return 0; + + return attr->mode; } static const struct attribute_group ili210x_attr_group = { .attrs = ili210x_attributes, - .is_visible = ili210x_calibrate_visible, + .is_visible = ili210x_attributes_visible, }; static void ili210x_power_down(void *data) @@ -465,6 +588,7 @@ static int ili210x_i2c_probe(struct i2c_client *client, priv->input = input; priv->reset_gpio = reset_gpio; priv->chip = chip; + mutex_init(&priv->lock); i2c_set_clientdata(client, priv); /* Setup input device */
The ili251x firmware protocol permits readout of firmware version, protocol version, mcu version and current mode (application, boot loader, forced update). These information are useful when updating the firmware on the il251x, e.g. to avoid updating the same firmware into the device multiple times. The locking is now necessary to avoid races between interrupt handler and the sysfs readouts. Note that the protocol differs considerably between the ili2xxx devices, this patch therefore implements this functionality only for ili251x that I can test. Signed-off-by: Marek Vasut <marex@denx.de> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Joe Hung <joe_hung@ilitek.com> Cc: Luca Hsu <luca_hsu@ilitek.com> --- V2: No change NOTE: Regarding checkpatch warnings, Consider renaming function(s) 'ili251x_firmware_version_show' to 'firmware_version_show', I considered it and decided against it, because grepping for ili251x in debug symbols gives far more accurate results than grepping for firmware_version. --- drivers/input/touchscreen/ili210x.c | 130 +++++++++++++++++++++++++++- 1 file changed, 127 insertions(+), 3 deletions(-)