| Message ID | 20190514105358.18818-1-fancer.lancer@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | usb: cp210x: Add cp2108 GPIOs support | expand |
On Tue, May 14, 2019 at 01:53:57PM +0300, Serge Semin wrote: > Each chip from the cp210x series got GPIOs on board. This commit > provides the support for sixteen ones placed on the cp2108 four-ports > serial console controller. All of the GPIOs are equally distributed > to four USB interfaces in accordance with GPIOs alternative functions > attachment. > > cp2108 GPIOs can be either in open-drain or push-pull modes setup once > after reset was cleared. In this matter it doesn't differ from the rest > of cp210x devices supported by the driver. So with minor alterations the > standard output/intput GPIO interface is implemented for cp2108. > > Aside from traditional GPIO functions like setting/getting pins value, > each GPIO is also multiplexed with alternative functions: TX/RX LEDs, RS485 > TX-enable and Clocks source. These functions can't be activated on-fly. > Instead the chips firmware should be properly setup, so they would be > enabled in the ports-config structure at the controller logic startup. > Needless to say, that when the alternative functions are activated, > the GPIOs can't be used. Thus we need to check the GPIO pin config in the > request callback and deny the request if GPIO standard function is > disabled. Thanks for the patch. I'm a bit worried about the logic getting too convoluted when dealing with the cp2108 and cp2105 differences. Please see if you can do something about that. Other than that, just some minor comments and request for clarifications. > Signed-off-by: Serge Semin <fancer.lancer@gmail.com> > --- > drivers/usb/serial/Kconfig | 2 +- > drivers/usb/serial/cp210x.c | 158 ++++++++++++++++++++++++++++++++---- > 2 files changed, 143 insertions(+), 17 deletions(-) > > diff --git a/drivers/usb/serial/Kconfig b/drivers/usb/serial/Kconfig > index 7d031911d04e..20bd4c0632c7 100644 > --- a/drivers/usb/serial/Kconfig > +++ b/drivers/usb/serial/Kconfig > @@ -138,7 +138,7 @@ config USB_SERIAL_DIGI_ACCELEPORT > config USB_SERIAL_CP210X > tristate "USB CP210x family of UART Bridge Controllers" > help > - Say Y here if you want to use a CP2101/CP2102/CP2103 based USB > + Say Y here if you want to use a CP2101/2/3/4/5/8 based USB Please drop this since it's a separate change. If anything we should probably just change this to "CP210X" not have to worry about it getting outdated again. > to RS232 converters. > > To compile this driver as a module, choose M here: the > diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c > index 979bef9bfb6b..a97f04d9e99f 100644 > --- a/drivers/usb/serial/cp210x.c > +++ b/drivers/usb/serial/cp210x.c > @@ -505,6 +505,56 @@ struct cp210x_gpio_write { > u8 state; > } __packed; > > +/* CP2108 interfaces, gpio (per interface), port-blocks number, GPIO block. */ > +#define CP2108_IFACE_NUM 4 > +#define CP2108_GPIO_NUM 4 > +#define CP2108_PB_NUM 5 > +#define CP2108_GPIO_PB 1 Please try to give these more descriptive names; I'd prefer COUNT over NUM when used as a suffix. Perhaps slap an INDEX suffix on CP2108_GPIO_PB etc. > +/* > + * CP2108 default pins state. There are five PBs. Each one is with its specific > + * pins-set (see USB Express SDK sources or SDK-based smt application > + * https://github.com/fancer/smt-cp210x for details). > + */ > +struct cp2108_state { > + __le16 mode[CP2108_PB_NUM]; /* 0 - Open-Drain, 1 - Push-Pull */ > + __le16 low_power[CP2108_PB_NUM]; > + __le16 latch[CP2108_PB_NUM]; /* 0 - Logic Low, 1 - Logic High */ > +} __packed; Ok, so you use mode[CP2108_GPIO_PB] to get the pin modes below; what are the other "PB"s used for? Why is it a "port" block, if all 16 pins allocated to four different ports are accessible through one block? Please try to make the comment self-contained (even if you leave some details out). And perhaps we shouldn't refer to proprietary code in here, and in any case the link may go away. > +/* > + * CP210X_VENDOR_SPECIFIC, CP210X_GET_PORTCONFIG call reads these 73 bytes. > + * Reset/Suspend latches describe default states after reset/suspend of the > + * pins. The rest are responsible for alternate functions settings of the > + * chip pins (see USB Express SDK sources or SDK-based smt application > + * https://github.com/fancer/smt-cp210x for details). > + */ > +struct cp2108_config { > + struct cp2108_state reset_latch; > + struct cp2108_state suspend_latch; > + u8 ip_delay[CP2108_IFACE_NUM]; > + u8 enhanced_fxn[CP2108_IFACE_NUM]; > + u8 enhanced_fxn_dev; > + u8 ext_clock_freq[CP2108_IFACE_NUM]; > +} __packed; > + > +/* CP2108 port alternate functions fields */ > +#define CP2108_GPIO_TXLED_MODE BIT(0) > +#define CP2108_GPIO_RXLED_MODE BIT(1) > +#define CP2108_GPIO_RS485_MODE BIT(2) > +#define CP2108_GPIO_RS485_LOGIC BIT(3) > +#define CP2108_GPIO_CLOCK_MODE BIT(4) > +#define CP2108_DYNAMIC_SUSPEND BIT(5) No GPIO infix? > + > +/* > + * CP210X_VENDOR_SPECIFIC, CP210X_WRITE_LATCH call writes these 0x4 bytes > + * to CP2108 controller. > + */ > +struct cp2108_gpio_write { > + __le16 mask; > + __le16 state; > +} __packed; No need for __packed (yes, I know there are other unnecessary __packed in this file). > /* > * Helper to get interface number when we only have struct usb_serial. > */ > @@ -1366,10 +1416,15 @@ static int cp210x_gpio_get(struct gpio_chip *gc, unsigned int gpio) > struct usb_serial *serial = gpiochip_get_data(gc); > struct cp210x_serial_private *priv = usb_get_serial_data(serial); > u8 req_type = REQTYPE_DEVICE_TO_HOST; > - int result; > - u8 buf; > - > - if (priv->partnum == CP210X_PARTNUM_CP2105) > + union { > + u8 single; > + __le16 dual; > + } buf; I wonder if this would become more readable if you just use u16, initialise to zero, read one byte unless cp2108, and then unconditionally do le16_to_cpus() before applying the mask. I want to keep the number of conditionals down, but if the logic is getting to hard to follow because cp2105 and cp2108 doing things differently we may need to add dedicated cp2108 (and maybe cp2105) get/set callbacks instead. > + int result, bufsize = sizeof(buf.single); One declaration per line please, especially when initialising. > + > + if (priv->partnum == CP210X_PARTNUM_CP2108) > + bufsize = sizeof(buf.dual); > + else if (priv->partnum == CP210X_PARTNUM_CP2105) > req_type = REQTYPE_INTERFACE_TO_HOST; > > result = usb_autopm_get_interface(serial->interface); > @@ -1377,39 +1432,51 @@ static int cp210x_gpio_get(struct gpio_chip *gc, unsigned int gpio) > return result; > > result = cp210x_read_vendor_block(serial, req_type, > - CP210X_READ_LATCH, &buf, sizeof(buf)); > + CP210X_READ_LATCH, &buf, bufsize); > usb_autopm_put_interface(serial->interface); > if (result < 0) > return result; > > - return !!(buf & BIT(gpio)); > + if (priv->partnum == CP210X_PARTNUM_CP2108) > + result = !!(le16_to_cpu(buf.dual) & BIT(gpio)); > + else > + result = !!(buf.single & BIT(gpio)); > + > + return result; > } > > static void cp210x_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value) > { > struct usb_serial *serial = gpiochip_get_data(gc); > struct cp210x_serial_private *priv = usb_get_serial_data(serial); > - struct cp210x_gpio_write buf; > int result; > > - if (value == 1) > - buf.state = BIT(gpio); > - else > - buf.state = 0; > - > - buf.mask = BIT(gpio); > - > result = usb_autopm_get_interface(serial->interface); > if (result) > goto out; > > - if (priv->partnum == CP210X_PARTNUM_CP2105) { > + if (priv->partnum == CP210X_PARTNUM_CP2108) { > + struct cp2108_gpio_write buf; > + > + buf.state = ((value == 1) ? cpu_to_le16(BIT(gpio)) : 0); > + buf.mask = cpu_to_le16(BIT(gpio)); > + > + result = cp210x_write_vendor_block(serial, > + REQTYPE_HOST_TO_DEVICE, > + CP210X_WRITE_LATCH, &buf, > + sizeof(buf)); > + } else if (priv->partnum == CP210X_PARTNUM_CP2105) { > + struct cp210x_gpio_write buf; > + > + buf.state = ((value == 1) ? BIT(gpio) : 0); > + buf.mask = BIT(gpio); > + > result = cp210x_write_vendor_block(serial, > REQTYPE_HOST_TO_INTERFACE, > CP210X_WRITE_LATCH, &buf, > sizeof(buf)); > } else { > - u16 wIndex = buf.state << 8 | buf.mask; > + u16 wIndex = ((value == 1) ? BIT(gpio) : 0) << 8 | BIT(gpio); This is way I try to avoid the ternary operator; too easy to write overly compact code. Please untangle again. > result = usb_control_msg(serial->dev, > usb_sndctrlpipe(serial->dev, 0), > @@ -1489,6 +1556,62 @@ static int cp210x_gpio_set_config(struct gpio_chip *gc, unsigned int gpio, > return -ENOTSUPP; > } > > +/* > + * CP2108 got 16 GPIOs, each of which can be configured either as input, or > + * as open-drain with weak pulling up to VIO or as push-pull with strong > + * pulling up to VIO. Similar to the rest of devices the open-drain mode > + * with latch set high is treated as input mode. All GPIOs are equally > + * distributed between four interfaces. Thanks to the mask-state based > + * write-latch control message we don't need to worry about possible races. > + */ > +static int cp2108_gpioconf_init(struct usb_serial *serial) > +{ > + struct cp210x_serial_private *priv = usb_get_serial_data(serial); > + struct cp2108_config config; > + u16 mode, latch; > + u8 intf_num; > + int result; > + > + result = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST, > + CP210X_GET_PORTCONFIG, &config, > + sizeof(config)); > + if (result < 0) > + return result; > + > + /* > + * There are four interfaces with four GPIOs for each port. Here we > + * parse the device config data to comply with the driver interface. > + * Note that the mode can be changed only after reset, which cause > + * the driver reloading anyway. So we can safely read the config just > + * once at attach procedure. > + */ > + intf_num = cp210x_interface_num(serial); > + mode = le16_to_cpu(config.reset_latch.mode[CP2108_GPIO_PB]); > + latch = le16_to_cpu(config.reset_latch.latch[CP2108_GPIO_PB]); > + > + priv->gpio_altfunc = config.enhanced_fxn[intf_num]; Missing sanity check on intf_num. > + priv->gpio_pushpull = (mode >> (intf_num*CP2108_GPIO_NUM)) & 0x0f; > + priv->gpio_input = (latch >> (intf_num*CP2108_GPIO_NUM)) & 0x0f; Missing spaces around multiplication operators. > + > + /* > + * Move the GPIO clock alternative function bit value to the fourth bit > + * as the corresponding GPIO pin reside. It shall make the generic > + * cp210x GPIO request method being suitable for cp2108 as well. > + */ This isn't entirely clear, please try to rephrase. Which functions are available on which pins? Do the function defines need to be renamed to reflect the pin numbers as for CP2104? > + priv->gpio_altfunc &= ~BIT(3); > + if (priv->gpio_altfunc & CP2108_GPIO_CLOCK_MODE) > + priv->gpio_altfunc |= BIT(3); > + > + /* > + * Open-drain mode in combination with a high latch value is used > + * to emulate the GPIO input pin. > + */ > + priv->gpio_input &= ~priv->gpio_pushpull; Input mode should only be set when the reset latch value is 1 (see cp2104). > + priv->gc.ngpio = CP2108_GPIO_NUM; Probably better to just use 4 directly instead of this define in this function (e.g. your mask above implicitly depends on it anyway). > + return 0; > +} Johan
Hello Johan On Mon, Jun 03, 2019 at 02:52:05PM +0200, Johan Hovold wrote: > On Tue, May 14, 2019 at 01:53:57PM +0300, Serge Semin wrote: > > Each chip from the cp210x series got GPIOs on board. This commit > > provides the support for sixteen ones placed on the cp2108 four-ports > > serial console controller. All of the GPIOs are equally distributed > > to four USB interfaces in accordance with GPIOs alternative functions > > attachment. > > > > cp2108 GPIOs can be either in open-drain or push-pull modes setup once > > after reset was cleared. In this matter it doesn't differ from the rest > > of cp210x devices supported by the driver. So with minor alterations the > > standard output/intput GPIO interface is implemented for cp2108. > > > > Aside from traditional GPIO functions like setting/getting pins value, > > each GPIO is also multiplexed with alternative functions: TX/RX LEDs, RS485 > > TX-enable and Clocks source. These functions can't be activated on-fly. > > Instead the chips firmware should be properly setup, so they would be > > enabled in the ports-config structure at the controller logic startup. > > Needless to say, that when the alternative functions are activated, > > the GPIOs can't be used. Thus we need to check the GPIO pin config in the > > request callback and deny the request if GPIO standard function is > > disabled. > > Thanks for the patch. > > I'm a bit worried about the logic getting too convoluted when dealing > with the cp2108 and cp2105 differences. Please see if you can do > something about that. > > Other than that, just some minor comments and request for > clarifications. > > > Signed-off-by: Serge Semin <fancer.lancer@gmail.com> > > --- > > drivers/usb/serial/Kconfig | 2 +- > > drivers/usb/serial/cp210x.c | 158 ++++++++++++++++++++++++++++++++---- > > 2 files changed, 143 insertions(+), 17 deletions(-) > > > > diff --git a/drivers/usb/serial/Kconfig b/drivers/usb/serial/Kconfig > > index 7d031911d04e..20bd4c0632c7 100644 > > --- a/drivers/usb/serial/Kconfig > > +++ b/drivers/usb/serial/Kconfig > > @@ -138,7 +138,7 @@ config USB_SERIAL_DIGI_ACCELEPORT > > config USB_SERIAL_CP210X > > tristate "USB CP210x family of UART Bridge Controllers" > > help > > - Say Y here if you want to use a CP2101/CP2102/CP2103 based USB > > + Say Y here if you want to use a CP2101/2/3/4/5/8 based USB > > Please drop this since it's a separate change. If anything we should > probably just change this to "CP210X" not have to worry about it getting > outdated again. > Ok. Moved to a separate patch. > > to RS232 converters. > > > > To compile this driver as a module, choose M here: the > > diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c > > index 979bef9bfb6b..a97f04d9e99f 100644 > > --- a/drivers/usb/serial/cp210x.c > > +++ b/drivers/usb/serial/cp210x.c > > @@ -505,6 +505,56 @@ struct cp210x_gpio_write { > > u8 state; > > } __packed; > > > > +/* CP2108 interfaces, gpio (per interface), port-blocks number, GPIO block. */ > > +#define CP2108_IFACE_NUM 4 > > +#define CP2108_GPIO_NUM 4 > > +#define CP2108_PB_NUM 5 > > +#define CP2108_GPIO_PB 1 > > Please try to give these more descriptive names; I'd prefer COUNT over > NUM when used as a suffix. > > Perhaps slap an INDEX suffix on CP2108_GPIO_PB etc. > Ok. Added CNT and IDX suffixes. > > +/* > > + * CP2108 default pins state. There are five PBs. Each one is with its specific > > + * pins-set (see USB Express SDK sources or SDK-based smt application > > + * https://github.com/fancer/smt-cp210x for details). > > + */ > > +struct cp2108_state { > > + __le16 mode[CP2108_PB_NUM]; /* 0 - Open-Drain, 1 - Push-Pull */ > > + __le16 low_power[CP2108_PB_NUM]; > > + __le16 latch[CP2108_PB_NUM]; /* 0 - Logic Low, 1 - Logic High */ > > +} __packed; > > Ok, so you use mode[CP2108_GPIO_PB] to get the pin modes below; > what are the other "PB"s used for? Why is it a "port" block, if all 16 > pins allocated to four different ports are accessible through one block? > > Please try to make the comment self-contained (even if you leave some > details out). And perhaps we shouldn't refer to proprietary code in > here, and in any case the link may go away. > Ok added a bit more detailed information regarding the port blocks. But I'd prefer to keep the link. First of all I can't provide the complete description of the fields here because it would take too much space and in fact is pointless since only a single port block with GPIOs is utilized. So the link and the SDK info are a good reference to find some details (especially due to lacking such an info in the chip datasheet). Secondly even though the code is distributed under the Silicon Labs specific license it is open-source. Finally the link may go away only if I removed the application from my github account, which I don't intend to. > > +/* > > + * CP210X_VENDOR_SPECIFIC, CP210X_GET_PORTCONFIG call reads these 73 bytes. > > + * Reset/Suspend latches describe default states after reset/suspend of the > > + * pins. The rest are responsible for alternate functions settings of the > > + * chip pins (see USB Express SDK sources or SDK-based smt application > > + * https://github.com/fancer/smt-cp210x for details). > > + */ > > +struct cp2108_config { > > + struct cp2108_state reset_latch; > > + struct cp2108_state suspend_latch; > > + u8 ip_delay[CP2108_IFACE_NUM]; > > + u8 enhanced_fxn[CP2108_IFACE_NUM]; > > + u8 enhanced_fxn_dev; > > + u8 ext_clock_freq[CP2108_IFACE_NUM]; > > +} __packed; > > + > > +/* CP2108 port alternate functions fields */ > > +#define CP2108_GPIO_TXLED_MODE BIT(0) > > +#define CP2108_GPIO_RXLED_MODE BIT(1) > > +#define CP2108_GPIO_RS485_MODE BIT(2) > > +#define CP2108_GPIO_RS485_LOGIC BIT(3) > > +#define CP2108_GPIO_CLOCK_MODE BIT(4) > > +#define CP2108_DYNAMIC_SUSPEND BIT(5) > > No GPIO infix? > No, because this refers to all pins state when the chip being suspended (whether the suspend_latch state is pushed to the pins at the suspend USB state), while the rest of the macros are defined for the GPIOs alternative functions. I'll add the MODE suffix though. > > + > > +/* > > + * CP210X_VENDOR_SPECIFIC, CP210X_WRITE_LATCH call writes these 0x4 bytes > > + * to CP2108 controller. > > + */ > > +struct cp2108_gpio_write { > > + __le16 mask; > > + __le16 state; > > +} __packed; > > No need for __packed (yes, I know there are other unnecessary __packed > in this file). > Ok. > > /* > > * Helper to get interface number when we only have struct usb_serial. > > */ > > @@ -1366,10 +1416,15 @@ static int cp210x_gpio_get(struct gpio_chip *gc, unsigned int gpio) > > struct usb_serial *serial = gpiochip_get_data(gc); > > struct cp210x_serial_private *priv = usb_get_serial_data(serial); > > u8 req_type = REQTYPE_DEVICE_TO_HOST; > > - int result; > > - u8 buf; > > - > > - if (priv->partnum == CP210X_PARTNUM_CP2105) > > + union { > > + u8 single; > > + __le16 dual; > > + } buf; > > I wonder if this would become more readable if you just use u16, > initialise to zero, read one byte unless cp2108, and then > unconditionally do le16_to_cpus() before applying the mask. > > I want to keep the number of conditionals down, but if the logic is > getting to hard to follow because cp2105 and cp2108 doing things > differently we may need to add dedicated cp2108 (and maybe cp2105) > get/set callbacks instead. > Ok. Replaced the union with u16 buffer. > > + int result, bufsize = sizeof(buf.single); > > One declaration per line please, especially when initialising. > Done. Though I can't remember this being requirement in the kernel coding style. Could you give me a link to the corresponding statement? > > + > > + if (priv->partnum == CP210X_PARTNUM_CP2108) > > + bufsize = sizeof(buf.dual); > > + else if (priv->partnum == CP210X_PARTNUM_CP2105) > > req_type = REQTYPE_INTERFACE_TO_HOST; > > > > result = usb_autopm_get_interface(serial->interface); > > @@ -1377,39 +1432,51 @@ static int cp210x_gpio_get(struct gpio_chip *gc, unsigned int gpio) > > return result; > > > > result = cp210x_read_vendor_block(serial, req_type, > > - CP210X_READ_LATCH, &buf, sizeof(buf)); > > + CP210X_READ_LATCH, &buf, bufsize); > > usb_autopm_put_interface(serial->interface); > > if (result < 0) > > return result; > > > > - return !!(buf & BIT(gpio)); > > + if (priv->partnum == CP210X_PARTNUM_CP2108) > > + result = !!(le16_to_cpu(buf.dual) & BIT(gpio)); > > + else > > + result = !!(buf.single & BIT(gpio)); > > + > > + return result; > > } > > > > static void cp210x_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value) > > { > > struct usb_serial *serial = gpiochip_get_data(gc); > > struct cp210x_serial_private *priv = usb_get_serial_data(serial); > > - struct cp210x_gpio_write buf; > > int result; > > > > - if (value == 1) > > - buf.state = BIT(gpio); > > - else > > - buf.state = 0; > > - > > - buf.mask = BIT(gpio); > > - > > result = usb_autopm_get_interface(serial->interface); > > if (result) > > goto out; > > > > - if (priv->partnum == CP210X_PARTNUM_CP2105) { > > + if (priv->partnum == CP210X_PARTNUM_CP2108) { > > + struct cp2108_gpio_write buf; > > + > > + buf.state = ((value == 1) ? cpu_to_le16(BIT(gpio)) : 0); > > + buf.mask = cpu_to_le16(BIT(gpio)); > > + > > + result = cp210x_write_vendor_block(serial, > > + REQTYPE_HOST_TO_DEVICE, > > + CP210X_WRITE_LATCH, &buf, > > + sizeof(buf)); > > + } else if (priv->partnum == CP210X_PARTNUM_CP2105) { > > + struct cp210x_gpio_write buf; > > + > > + buf.state = ((value == 1) ? BIT(gpio) : 0); > > + buf.mask = BIT(gpio); > > + > > result = cp210x_write_vendor_block(serial, > > REQTYPE_HOST_TO_INTERFACE, > > CP210X_WRITE_LATCH, &buf, > > sizeof(buf)); > > } else { > > - u16 wIndex = buf.state << 8 | buf.mask; > > + u16 wIndex = ((value == 1) ? BIT(gpio) : 0) << 8 | BIT(gpio); > > This is way I try to avoid the ternary operator; too easy to write > overly compact code. Please untangle again. > Ok. Untangled all the ternary operations utilized in this function. > > result = usb_control_msg(serial->dev, > > usb_sndctrlpipe(serial->dev, 0), > > @@ -1489,6 +1556,62 @@ static int cp210x_gpio_set_config(struct gpio_chip *gc, unsigned int gpio, > > return -ENOTSUPP; > > } > > > > +/* > > + * CP2108 got 16 GPIOs, each of which can be configured either as input, or > > + * as open-drain with weak pulling up to VIO or as push-pull with strong > > + * pulling up to VIO. Similar to the rest of devices the open-drain mode > > + * with latch set high is treated as input mode. All GPIOs are equally > > + * distributed between four interfaces. Thanks to the mask-state based > > + * write-latch control message we don't need to worry about possible races. > > + */ > > +static int cp2108_gpioconf_init(struct usb_serial *serial) > > +{ > > + struct cp210x_serial_private *priv = usb_get_serial_data(serial); > > + struct cp2108_config config; > > + u16 mode, latch; > > + u8 intf_num; > > + int result; > > + > > + result = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST, > > + CP210X_GET_PORTCONFIG, &config, > > + sizeof(config)); > > + if (result < 0) > > + return result; > > + > > + /* > > + * There are four interfaces with four GPIOs for each port. Here we > > + * parse the device config data to comply with the driver interface. > > + * Note that the mode can be changed only after reset, which cause > > + * the driver reloading anyway. So we can safely read the config just > > + * once at attach procedure. > > + */ > > + intf_num = cp210x_interface_num(serial); > > + mode = le16_to_cpu(config.reset_latch.mode[CP2108_GPIO_PB]); > > + latch = le16_to_cpu(config.reset_latch.latch[CP2108_GPIO_PB]); > > + > > + priv->gpio_altfunc = config.enhanced_fxn[intf_num]; > > Missing sanity check on intf_num. > Done. > > + priv->gpio_pushpull = (mode >> (intf_num*CP2108_GPIO_NUM)) & 0x0f; > > + priv->gpio_input = (latch >> (intf_num*CP2108_GPIO_NUM)) & 0x0f; > > Missing spaces around multiplication operators. > Done. > > + > > + /* > > + * Move the GPIO clock alternative function bit value to the fourth bit > > + * as the corresponding GPIO pin reside. It shall make the generic > > + * cp210x GPIO request method being suitable for cp2108 as well. > > + */ > > This isn't entirely clear, please try to rephrase. > > Which functions are available on which pins? Do the function defines > need to be renamed to reflect the pin numbers as for CP2104? > I wouldn't rename the macros'es, since they describe the functions of enhanced_fxn bits. BTW CP2104 doesn't do any renaming anyway, while it is doing the same thing as I am here. Instead I added a more descriptive comment, so the code hackers would see the reason of the BITs copy-pasting. > > + priv->gpio_altfunc &= ~BIT(3); > > + if (priv->gpio_altfunc & CP2108_GPIO_CLOCK_MODE) > > + priv->gpio_altfunc |= BIT(3); > > + > > + /* > > + * Open-drain mode in combination with a high latch value is used > > + * to emulate the GPIO input pin. > > + */ > > + priv->gpio_input &= ~priv->gpio_pushpull; > > Input mode should only be set when the reset latch value is 1 (see > cp2104). > Yes, and this code does the same thing as the loop in cp2104, but in a single line. BTW the cp2104 cp2104_gpioconf_init() method can be simplified in the same way.stash@{0}stash@{0} > > + priv->gc.ngpio = CP2108_GPIO_NUM; > > Probably better to just use 4 directly instead of this define in this > function (e.g. your mask above implicitly depends on it anyway). > Ok. Removed the macro from this function. It should be also noted that in v2 I fixed a cp2108-related bug in the cp210x_gpio_get()/cp210x_gpio_set() methods. So aside from the requested alterations the logic of the cp2108 GPIOs setter/getter is bit different now. Regards, -Sergey > > + return 0; > > +} > > Johan
On Sun, Jun 16, 2019 at 01:56:36AM +0300, Serge Semin wrote: > > > +/* CP2108 interfaces, gpio (per interface), port-blocks number, GPIO block. */ > > > +#define CP2108_IFACE_NUM 4 > > > +#define CP2108_GPIO_NUM 4 > > > +#define CP2108_PB_NUM 5 > > > +#define CP2108_GPIO_PB 1 > > > > Please try to give these more descriptive names; I'd prefer COUNT over > > NUM when used as a suffix. > > > > Perhaps slap an INDEX suffix on CP2108_GPIO_PB etc. > > Ok. Added CNT and IDX suffixes. Please spell out COUNT, no need to be that terse here. > > > +/* > > > + * CP2108 default pins state. There are five PBs. Each one is with its specific > > > + * pins-set (see USB Express SDK sources or SDK-based smt application > > > + * https://github.com/fancer/smt-cp210x for details). > > > + */ > > > +struct cp2108_state { > > > + __le16 mode[CP2108_PB_NUM]; /* 0 - Open-Drain, 1 - Push-Pull */ > > > + __le16 low_power[CP2108_PB_NUM]; > > > + __le16 latch[CP2108_PB_NUM]; /* 0 - Logic Low, 1 - Logic High */ > > > +} __packed; > > > > Ok, so you use mode[CP2108_GPIO_PB] to get the pin modes below; > > what are the other "PB"s used for? Why is it a "port" block, if all 16 > > pins allocated to four different ports are accessible through one block? > > > > Please try to make the comment self-contained (even if you leave some > > details out). And perhaps we shouldn't refer to proprietary code in > > here, and in any case the link may go away. > > > > Ok added a bit more detailed information regarding the port blocks. But > I'd prefer to keep the link. First of all I can't provide the complete > description of the fields here because it would take too much space and > in fact is pointless since only a single port block with GPIOs is utilized. > So the link and the SDK info are a good reference to find some details > (especially due to lacking such an info in the chip datasheet). I never said it had to be complete, just self-contained for what it's used for here. I don't want to go browsing random vendor code to figure out what the code is doing when reviewing or modifying kernel code. > Secondly even though the code is distributed under the Silicon Labs > specific license it is open-source. But it's not necessarily GPL compatible, which is what we care about here. Then again, you've already used it as reference for the protocol, so let's keep it in. > Finally the link may go away only > if I removed the application from my github account, which I don't > intend to. Ok, didn't notice it was your account. > > > +/* > > > + * CP210X_VENDOR_SPECIFIC, CP210X_GET_PORTCONFIG call reads these 73 bytes. > > > + * Reset/Suspend latches describe default states after reset/suspend of the > > > + * pins. The rest are responsible for alternate functions settings of the > > > + * chip pins (see USB Express SDK sources or SDK-based smt application > > > + * https://github.com/fancer/smt-cp210x for details). > > > + */ > > > +struct cp2108_config { > > > + struct cp2108_state reset_latch; > > > + struct cp2108_state suspend_latch; > > > + u8 ip_delay[CP2108_IFACE_NUM]; > > > + u8 enhanced_fxn[CP2108_IFACE_NUM]; > > > + u8 enhanced_fxn_dev; > > > + u8 ext_clock_freq[CP2108_IFACE_NUM]; > > > +} __packed; > > > + > > > +/* CP2108 port alternate functions fields */ So it's really the enhanced_fxn field above right (and not about pin alternate functions only). > > > +#define CP2108_GPIO_TXLED_MODE BIT(0) > > > +#define CP2108_GPIO_RXLED_MODE BIT(1) > > > +#define CP2108_GPIO_RS485_MODE BIT(2) > > > +#define CP2108_GPIO_RS485_LOGIC BIT(3) > > > +#define CP2108_GPIO_CLOCK_MODE BIT(4) > > > +#define CP2108_DYNAMIC_SUSPEND BIT(5) > > > > No GPIO infix? > > No, because this refers to all pins state when the chip being suspended > (whether the suspend_latch state is pushed to the pins at the suspend USB > state), while the rest of the macros are defined for the GPIOs alternative > functions. I'll add the MODE suffix though. Ok, does the pins maintain their state if DYNAMIC_SUSPEND is set or cleared? > > > + int result, bufsize = sizeof(buf.single); > > > > One declaration per line please, especially when initialising. > > Done. Though I can't remember this being requirement in the kernel > coding style. Could you give me a link to the corresponding statement? It's actually mentioned in passing in the coding style, but with a different motivation. The general idea is just to avoid unnecessarily terse code. > > > + > > > + /* > > > + * Move the GPIO clock alternative function bit value to the fourth bit > > > + * as the corresponding GPIO pin reside. It shall make the generic > > > + * cp210x GPIO request method being suitable for cp2108 as well. > > > + */ > > > > This isn't entirely clear, please try to rephrase. > > > > Which functions are available on which pins? Do the function defines > > need to be renamed to reflect the pin numbers as for CP2104? > > I wouldn't rename the macros'es, since they describe the functions of > enhanced_fxn bits. BTW CP2104 doesn't do any renaming anyway, while it > is doing the same thing as I am here. Instead I added a more descriptive > comment, so the code hackers would see the reason of the BITs copy-pasting. My point was that the corresponding macros for cp2104 includes the pin number in the name (e.g. CP2104_GPIO1_RXLED_MODE), which makes it clear on which pin each alternate function is available. > > > + priv->gpio_altfunc &= ~BIT(3); > > > + if (priv->gpio_altfunc & CP2108_GPIO_CLOCK_MODE) > > > + priv->gpio_altfunc |= BIT(3); > > > + > > > + /* > > > + * Open-drain mode in combination with a high latch value is used > > > + * to emulate the GPIO input pin. > > > + */ > > > + priv->gpio_input &= ~priv->gpio_pushpull; > > > > Input mode should only be set when the reset latch value is 1 (see > > cp2104). > > Yes, and this code does the same thing as the loop in cp2104, but in a single > line. BTW the cp2104 cp2104_gpioconf_init() method can be simplified in the > same way.stash@{0}stash@{0} Not in a single line, you initialised gpio_input to the latch values several lines above. Please keep the logic in one place, and use temporaries where appropriate to make the code self-documenting. I'd prefer a comment here along the lines of those in the other gpio init functions (e.g. "set input mode iff open-drain and high latch value"). > It should be also noted that in v2 I fixed a cp2108-related bug in the > cp210x_gpio_get()/cp210x_gpio_set() methods. So aside from the requested > alterations the logic of the cp2108 GPIOs setter/getter is bit different > now. Ah, guess you had only tested the first port's pins? Possibly another reason for adding a dedicated cp2108 callback. I'll comment on the patch itself. Johan
diff --git a/drivers/usb/serial/Kconfig b/drivers/usb/serial/Kconfig index 7d031911d04e..20bd4c0632c7 100644 --- a/drivers/usb/serial/Kconfig +++ b/drivers/usb/serial/Kconfig @@ -138,7 +138,7 @@ config USB_SERIAL_DIGI_ACCELEPORT config USB_SERIAL_CP210X tristate "USB CP210x family of UART Bridge Controllers" help - Say Y here if you want to use a CP2101/CP2102/CP2103 based USB + Say Y here if you want to use a CP2101/2/3/4/5/8 based USB to RS232 converters. To compile this driver as a module, choose M here: the diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c index 979bef9bfb6b..a97f04d9e99f 100644 --- a/drivers/usb/serial/cp210x.c +++ b/drivers/usb/serial/cp210x.c @@ -505,6 +505,56 @@ struct cp210x_gpio_write { u8 state; } __packed; +/* CP2108 interfaces, gpio (per interface), port-blocks number, GPIO block. */ +#define CP2108_IFACE_NUM 4 +#define CP2108_GPIO_NUM 4 +#define CP2108_PB_NUM 5 +#define CP2108_GPIO_PB 1 + +/* + * CP2108 default pins state. There are five PBs. Each one is with its specific + * pins-set (see USB Express SDK sources or SDK-based smt application + * https://github.com/fancer/smt-cp210x for details). + */ +struct cp2108_state { + __le16 mode[CP2108_PB_NUM]; /* 0 - Open-Drain, 1 - Push-Pull */ + __le16 low_power[CP2108_PB_NUM]; + __le16 latch[CP2108_PB_NUM]; /* 0 - Logic Low, 1 - Logic High */ +} __packed; + +/* + * CP210X_VENDOR_SPECIFIC, CP210X_GET_PORTCONFIG call reads these 73 bytes. + * Reset/Suspend latches describe default states after reset/suspend of the + * pins. The rest are responsible for alternate functions settings of the + * chip pins (see USB Express SDK sources or SDK-based smt application + * https://github.com/fancer/smt-cp210x for details). + */ +struct cp2108_config { + struct cp2108_state reset_latch; + struct cp2108_state suspend_latch; + u8 ip_delay[CP2108_IFACE_NUM]; + u8 enhanced_fxn[CP2108_IFACE_NUM]; + u8 enhanced_fxn_dev; + u8 ext_clock_freq[CP2108_IFACE_NUM]; +} __packed; + +/* CP2108 port alternate functions fields */ +#define CP2108_GPIO_TXLED_MODE BIT(0) +#define CP2108_GPIO_RXLED_MODE BIT(1) +#define CP2108_GPIO_RS485_MODE BIT(2) +#define CP2108_GPIO_RS485_LOGIC BIT(3) +#define CP2108_GPIO_CLOCK_MODE BIT(4) +#define CP2108_DYNAMIC_SUSPEND BIT(5) + +/* + * CP210X_VENDOR_SPECIFIC, CP210X_WRITE_LATCH call writes these 0x4 bytes + * to CP2108 controller. + */ +struct cp2108_gpio_write { + __le16 mask; + __le16 state; +} __packed; + /* * Helper to get interface number when we only have struct usb_serial. */ @@ -1366,10 +1416,15 @@ static int cp210x_gpio_get(struct gpio_chip *gc, unsigned int gpio) struct usb_serial *serial = gpiochip_get_data(gc); struct cp210x_serial_private *priv = usb_get_serial_data(serial); u8 req_type = REQTYPE_DEVICE_TO_HOST; - int result; - u8 buf; - - if (priv->partnum == CP210X_PARTNUM_CP2105) + union { + u8 single; + __le16 dual; + } buf; + int result, bufsize = sizeof(buf.single); + + if (priv->partnum == CP210X_PARTNUM_CP2108) + bufsize = sizeof(buf.dual); + else if (priv->partnum == CP210X_PARTNUM_CP2105) req_type = REQTYPE_INTERFACE_TO_HOST; result = usb_autopm_get_interface(serial->interface); @@ -1377,39 +1432,51 @@ static int cp210x_gpio_get(struct gpio_chip *gc, unsigned int gpio) return result; result = cp210x_read_vendor_block(serial, req_type, - CP210X_READ_LATCH, &buf, sizeof(buf)); + CP210X_READ_LATCH, &buf, bufsize); usb_autopm_put_interface(serial->interface); if (result < 0) return result; - return !!(buf & BIT(gpio)); + if (priv->partnum == CP210X_PARTNUM_CP2108) + result = !!(le16_to_cpu(buf.dual) & BIT(gpio)); + else + result = !!(buf.single & BIT(gpio)); + + return result; } static void cp210x_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value) { struct usb_serial *serial = gpiochip_get_data(gc); struct cp210x_serial_private *priv = usb_get_serial_data(serial); - struct cp210x_gpio_write buf; int result; - if (value == 1) - buf.state = BIT(gpio); - else - buf.state = 0; - - buf.mask = BIT(gpio); - result = usb_autopm_get_interface(serial->interface); if (result) goto out; - if (priv->partnum == CP210X_PARTNUM_CP2105) { + if (priv->partnum == CP210X_PARTNUM_CP2108) { + struct cp2108_gpio_write buf; + + buf.state = ((value == 1) ? cpu_to_le16(BIT(gpio)) : 0); + buf.mask = cpu_to_le16(BIT(gpio)); + + result = cp210x_write_vendor_block(serial, + REQTYPE_HOST_TO_DEVICE, + CP210X_WRITE_LATCH, &buf, + sizeof(buf)); + } else if (priv->partnum == CP210X_PARTNUM_CP2105) { + struct cp210x_gpio_write buf; + + buf.state = ((value == 1) ? BIT(gpio) : 0); + buf.mask = BIT(gpio); + result = cp210x_write_vendor_block(serial, REQTYPE_HOST_TO_INTERFACE, CP210X_WRITE_LATCH, &buf, sizeof(buf)); } else { - u16 wIndex = buf.state << 8 | buf.mask; + u16 wIndex = ((value == 1) ? BIT(gpio) : 0) << 8 | BIT(gpio); result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), @@ -1489,6 +1556,62 @@ static int cp210x_gpio_set_config(struct gpio_chip *gc, unsigned int gpio, return -ENOTSUPP; } +/* + * CP2108 got 16 GPIOs, each of which can be configured either as input, or + * as open-drain with weak pulling up to VIO or as push-pull with strong + * pulling up to VIO. Similar to the rest of devices the open-drain mode + * with latch set high is treated as input mode. All GPIOs are equally + * distributed between four interfaces. Thanks to the mask-state based + * write-latch control message we don't need to worry about possible races. + */ +static int cp2108_gpioconf_init(struct usb_serial *serial) +{ + struct cp210x_serial_private *priv = usb_get_serial_data(serial); + struct cp2108_config config; + u16 mode, latch; + u8 intf_num; + int result; + + result = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST, + CP210X_GET_PORTCONFIG, &config, + sizeof(config)); + if (result < 0) + return result; + + /* + * There are four interfaces with four GPIOs for each port. Here we + * parse the device config data to comply with the driver interface. + * Note that the mode can be changed only after reset, which cause + * the driver reloading anyway. So we can safely read the config just + * once at attach procedure. + */ + intf_num = cp210x_interface_num(serial); + mode = le16_to_cpu(config.reset_latch.mode[CP2108_GPIO_PB]); + latch = le16_to_cpu(config.reset_latch.latch[CP2108_GPIO_PB]); + + priv->gpio_altfunc = config.enhanced_fxn[intf_num]; + priv->gpio_pushpull = (mode >> (intf_num*CP2108_GPIO_NUM)) & 0x0f; + priv->gpio_input = (latch >> (intf_num*CP2108_GPIO_NUM)) & 0x0f; + + /* + * Move the GPIO clock alternative function bit value to the fourth bit + * as the corresponding GPIO pin reside. It shall make the generic + * cp210x GPIO request method being suitable for cp2108 as well. + */ + priv->gpio_altfunc &= ~BIT(3); + if (priv->gpio_altfunc & CP2108_GPIO_CLOCK_MODE) + priv->gpio_altfunc |= BIT(3); + + /* + * Open-drain mode in combination with a high latch value is used + * to emulate the GPIO input pin. + */ + priv->gpio_input &= ~priv->gpio_pushpull; + priv->gc.ngpio = CP2108_GPIO_NUM; + + return 0; +} + /* * This function is for configuring GPIO using shared pins, where other signals * are made unavailable by configuring the use of GPIO. This is believed to be @@ -1713,6 +1836,9 @@ static int cp210x_gpio_init(struct usb_serial *serial) case CP210X_PARTNUM_CP2105: result = cp2105_gpioconf_init(serial); break; + case CP210X_PARTNUM_CP2108: + result = cp2108_gpioconf_init(serial); + break; case CP210X_PARTNUM_CP2102N_QFN28: case CP210X_PARTNUM_CP2102N_QFN24: case CP210X_PARTNUM_CP2102N_QFN20:
Each chip from the cp210x series got GPIOs on board. This commit provides the support for sixteen ones placed on the cp2108 four-ports serial console controller. All of the GPIOs are equally distributed to four USB interfaces in accordance with GPIOs alternative functions attachment. cp2108 GPIOs can be either in open-drain or push-pull modes setup once after reset was cleared. In this matter it doesn't differ from the rest of cp210x devices supported by the driver. So with minor alterations the standard output/intput GPIO interface is implemented for cp2108. Aside from traditional GPIO functions like setting/getting pins value, each GPIO is also multiplexed with alternative functions: TX/RX LEDs, RS485 TX-enable and Clocks source. These functions can't be activated on-fly. Instead the chips firmware should be properly setup, so they would be enabled in the ports-config structure at the controller logic startup. Needless to say, that when the alternative functions are activated, the GPIOs can't be used. Thus we need to check the GPIO pin config in the request callback and deny the request if GPIO standard function is disabled. Signed-off-by: Serge Semin <fancer.lancer@gmail.com> --- drivers/usb/serial/Kconfig | 2 +- drivers/usb/serial/cp210x.c | 158 ++++++++++++++++++++++++++++++++---- 2 files changed, 143 insertions(+), 17 deletions(-)