| Message ID | 20230928151631.149333-6-jcmvbkbc@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | serial: add drivers for the ESP32xx serial devices | expand |
On Thu, Sep 28, 2023 at 08:16:31AM -0700, Max Filippov wrote: > Add driver for the ACM controller of the Espressif ESP32S3 Soc. Odd extra space :( > Hardware specification is available at the following URL: > > https://www.espressif.com/sites/default/files/documentation/esp32-s3_technical_reference_manual_en.pdf > (Chapter 33 USB Serial/JTAG Controller) I don't understand this driver, "ACM" is a USB host <-> gadget protocol, why do you need a platform serial driver for this? > > Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> > --- > Changes v2->v3: > - use HZ instead of msecs_to_jiffies(1000) in esp32_acm_put_char_sync > - add early return to esp32_acm_transmit_buffer > - use request_irq/free_irq instead of devm_* versions > > Changes v1->v2: > - redefine register fields using BIT and GENMASK > - drop _MASK suffix from register field definitions > - drop *_SHIFT definitions where possible > - split register reads/writes and bitwise operations into multiple lines > - use u8 instead of unsigned char in internal functions > - add timeout to esp32_acm_put_char_sync > - use uart_port_tx_limited in esp32_acm_transmit_buffer > - use IRQ_RETVAL in esp32_acm_int > - drop esp32s3_acm_console_putchar and esp32s3_acm_earlycon_putchar > - turn num_read into unsigned int in esp32_acm_earlycon_read > - drop MODULE_DESCRIPTION > > drivers/tty/serial/Kconfig | 14 + > drivers/tty/serial/Makefile | 1 + > drivers/tty/serial/esp32_acm.c | 459 +++++++++++++++++++++++++++++++ > include/uapi/linux/serial_core.h | 3 + > 4 files changed, 477 insertions(+) > create mode 100644 drivers/tty/serial/esp32_acm.c > > diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig > index d9ca6b268f01..85807db8f7ce 100644 > --- a/drivers/tty/serial/Kconfig > +++ b/drivers/tty/serial/Kconfig > @@ -1591,6 +1591,20 @@ config SERIAL_ESP32 > earlycon=esp32s3uart,mmio32,0x60000000,115200n8,40000000 > earlycon=esp32uart,mmio32,0x3ff40000,115200n8 > > +config SERIAL_ESP32_ACM > + tristate "Espressif ESP32 USB ACM support" > + depends on XTENSA_PLATFORM_ESP32 || (COMPILE_TEST && OF) > + select SERIAL_CORE > + select SERIAL_CORE_CONSOLE > + select SERIAL_EARLYCON > + help > + Driver for the CDC ACM controllers of the Espressif ESP32S3 SoCs > + that share separate USB controller with the JTAG adapter. > + The device name used for this controller is ttyACM. > + When earlycon option is enabled the following kernel command line > + snippet may be used: > + earlycon=esp32s3acm,mmio32,0x60038000 > + > endmenu > > config SERIAL_MCTRL_GPIO > diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile > index 7b73137df7f3..970a292ca418 100644 > --- a/drivers/tty/serial/Makefile > +++ b/drivers/tty/serial/Makefile > @@ -89,6 +89,7 @@ obj-$(CONFIG_SERIAL_SIFIVE) += sifive.o > obj-$(CONFIG_SERIAL_LITEUART) += liteuart.o > obj-$(CONFIG_SERIAL_SUNPLUS) += sunplus-uart.o > obj-$(CONFIG_SERIAL_ESP32) += esp32_uart.o > +obj-$(CONFIG_SERIAL_ESP32_ACM) += esp32_acm.o > > # GPIOLIB helpers for modem control lines > obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o > diff --git a/drivers/tty/serial/esp32_acm.c b/drivers/tty/serial/esp32_acm.c > new file mode 100644 > index 000000000000..f02abd2ac65e > --- /dev/null > +++ b/drivers/tty/serial/esp32_acm.c > @@ -0,0 +1,459 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later Why "or later"? I have to ask, sorry. And no copyright information? That's fine, but be sure your company's lawyers are ok with it... > + > +#include <linux/bitfield.h> > +#include <linux/bits.h> > +#include <linux/console.h> > +#include <linux/delay.h> > +#include <linux/io.h> > +#include <linux/irq.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/of_device.h> > +#include <linux/serial_core.h> > +#include <linux/slab.h> > +#include <linux/tty_flip.h> > +#include <asm/serial.h> > + > +#define DRIVER_NAME "esp32s3-acm" > +#define DEV_NAME "ttyACM" There is already a ttyACM driver in the kernel, will this conflict with that one? And are you using the same major/minor numbers for it as well? If so, how is this going to work? > +#define UART_NR 4 > + > +#define ESP32S3_ACM_TX_FIFO_SIZE 64 > + > +#define USB_SERIAL_JTAG_EP1_REG 0x00 > +#define USB_SERIAL_JTAG_EP1_CONF_REG 0x04 > +#define USB_SERIAL_JTAG_WR_DONE BIT(0) > +#define USB_SERIAL_JTAG_SERIAL_IN_EP_DATA_FREE BIT(1) > +#define USB_SERIAL_JTAG_INT_ST_REG 0x0c > +#define USB_SERIAL_JTAG_SERIAL_OUT_RECV_PKT_INT_ST BIT(2) > +#define USB_SERIAL_JTAG_SERIAL_IN_EMPTY_INT_ST BIT(3) > +#define USB_SERIAL_JTAG_INT_ENA_REG 0x10 > +#define USB_SERIAL_JTAG_SERIAL_OUT_RECV_PKT_INT_ENA BIT(2) > +#define USB_SERIAL_JTAG_SERIAL_IN_EMPTY_INT_ENA BIT(3) > +#define USB_SERIAL_JTAG_INT_CLR_REG 0x14 > +#define USB_SERIAL_JTAG_IN_EP1_ST_REG 0x2c > +#define USB_SERIAL_JTAG_IN_EP1_WR_ADDR GENMASK(8, 2) > +#define USB_SERIAL_JTAG_OUT_EP1_ST_REG 0x3c > +#define USB_SERIAL_JTAG_OUT_EP1_REC_DATA_CNT GENMASK(22, 16) > + > +static const struct of_device_id esp32s3_acm_dt_ids[] = { > + { > + .compatible = "esp,esp32s3-acm", > + }, { /* sentinel */ } > +}; > +MODULE_DEVICE_TABLE(of, esp32s3_acm_dt_ids); > + > +static struct uart_port *esp32s3_acm_ports[UART_NR]; > + > +static void esp32s3_acm_write(struct uart_port *port, unsigned long reg, u32 v) > +{ > + writel(v, port->membase + reg); > +} > + > +static u32 esp32s3_acm_read(struct uart_port *port, unsigned long reg) > +{ > + return readl(port->membase + reg); > +} > + > +static u32 esp32s3_acm_tx_fifo_free(struct uart_port *port) > +{ > + u32 status = esp32s3_acm_read(port, USB_SERIAL_JTAG_EP1_CONF_REG); > + > + return status & USB_SERIAL_JTAG_SERIAL_IN_EP_DATA_FREE; > +} > + > +static u32 esp32s3_acm_tx_fifo_cnt(struct uart_port *port) > +{ > + u32 status = esp32s3_acm_read(port, USB_SERIAL_JTAG_IN_EP1_ST_REG); > + > + return FIELD_GET(USB_SERIAL_JTAG_IN_EP1_WR_ADDR, status); > +} > + > +static u32 esp32s3_acm_rx_fifo_cnt(struct uart_port *port) > +{ > + u32 status = esp32s3_acm_read(port, USB_SERIAL_JTAG_OUT_EP1_ST_REG); > + > + return FIELD_GET(USB_SERIAL_JTAG_OUT_EP1_REC_DATA_CNT, status); > +} > + > +/* return TIOCSER_TEMT when transmitter is not busy */ > +static unsigned int esp32s3_acm_tx_empty(struct uart_port *port) > +{ > + return esp32s3_acm_tx_fifo_cnt(port) == 0 ? TIOCSER_TEMT : 0; > +} > + > +static void esp32s3_acm_set_mctrl(struct uart_port *port, unsigned int mctrl) > +{ > +} Do you have to have empty functions for callbacks that do nothing? > --- a/include/uapi/linux/serial_core.h > +++ b/include/uapi/linux/serial_core.h > @@ -248,4 +248,7 @@ > /* Espressif ESP32 UART */ > #define PORT_ESP32UART 124 > > +/* Espressif ESP32 ACM */ > +#define PORT_ESP32ACM 125 Why are these defines needed? What in userspace is going to require them? If nothing, please do not add them. thanks, greg k-h
On Tue, Oct 3, 2023 at 5:55 AM Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote: > > On Thu, Sep 28, 2023 at 08:16:31AM -0700, Max Filippov wrote: > > Add driver for the ACM controller of the Espressif ESP32S3 Soc. > > Odd extra space :( Ok. > > Hardware specification is available at the following URL: > > > > https://www.espressif.com/sites/default/files/documentation/esp32-s3_technical_reference_manual_en.pdf > > (Chapter 33 USB Serial/JTAG Controller) > > I don't understand this driver, "ACM" is a USB host <-> gadget protocol, > why do you need a platform serial driver for this? The USB part of this piece of hardware is fixed and not controllable, so all we have is a very limited UART interface. But to the outside world it's a USB device with the CDC-ACM interface. > > diff --git a/drivers/tty/serial/esp32_acm.c b/drivers/tty/serial/esp32_acm.c > > new file mode 100644 > > index 000000000000..f02abd2ac65e > > --- /dev/null > > +++ b/drivers/tty/serial/esp32_acm.c > > @@ -0,0 +1,459 @@ > > +// SPDX-License-Identifier: GPL-2.0-or-later > > Why "or later"? I have to ask, sorry. I don't really have a preference here. Is there a reason to choose GPL-2.0 only for a new code? > And no copyright information? That's fine, but be sure your company's > lawyers are ok with it... There's no company behind this, just myself. > > + > > +#include <linux/bitfield.h> > > +#include <linux/bits.h> > > +#include <linux/console.h> > > +#include <linux/delay.h> > > +#include <linux/io.h> > > +#include <linux/irq.h> > > +#include <linux/module.h> > > +#include <linux/of.h> > > +#include <linux/of_device.h> > > +#include <linux/serial_core.h> > > +#include <linux/slab.h> > > +#include <linux/tty_flip.h> > > +#include <asm/serial.h> > > + > > +#define DRIVER_NAME "esp32s3-acm" > > +#define DEV_NAME "ttyACM" > > There is already a ttyACM driver in the kernel, will this conflict with > that one? And are you using the same major/minor numbers for it as > well? If so, how is this going to work? I'll rename it to ttyS. I see that it coexists with the other driver that calls its devices ttyS just fine. > > +static void esp32s3_acm_set_mctrl(struct uart_port *port, unsigned int mctrl) > > +{ > > +} > > Do you have to have empty functions for callbacks that do nothing? The serial core has unconditional calls to these callbacks. > > --- a/include/uapi/linux/serial_core.h > > +++ b/include/uapi/linux/serial_core.h > > @@ -248,4 +248,7 @@ > > /* Espressif ESP32 UART */ > > #define PORT_ESP32UART 124 > > > > +/* Espressif ESP32 ACM */ > > +#define PORT_ESP32ACM 125 > > Why are these defines needed? What in userspace is going to require > them? If nothing, please do not add them. I don't understand what the alternatives are. The comment for the uart_ops::config_port() callback says that port->type should be set to the type of the port found, and I see that almost every serial driver defines a unique PORT_* for that.
On Tue, Oct 03, 2023 at 12:46:46PM -0700, Max Filippov wrote: > > > Hardware specification is available at the following URL: > > > > > > https://www.espressif.com/sites/default/files/documentation/esp32-s3_technical_reference_manual_en.pdf > > > (Chapter 33 USB Serial/JTAG Controller) > > > > I don't understand this driver, "ACM" is a USB host <-> gadget protocol, > > why do you need a platform serial driver for this? > > The USB part of this piece of hardware is fixed and not controllable, so > all we have is a very limited UART interface. But to the outside world > it's a USB device with the CDC-ACM interface. Where is the "outside world" here? The other end of the tty connection? So this is a "ACM gadget"? If so, please try to use that term as that's what we use in the kernel to keep things straight. > > > diff --git a/drivers/tty/serial/esp32_acm.c b/drivers/tty/serial/esp32_acm.c > > > new file mode 100644 > > > index 000000000000..f02abd2ac65e > > > --- /dev/null > > > +++ b/drivers/tty/serial/esp32_acm.c > > > @@ -0,0 +1,459 @@ > > > +// SPDX-License-Identifier: GPL-2.0-or-later > > > > Why "or later"? I have to ask, sorry. > > I don't really have a preference here. Is there a reason to choose > GPL-2.0 only for a new code? It's your call, you need to pick that, but I can provide recommendations if you want :) > > And no copyright information? That's fine, but be sure your company's > > lawyers are ok with it... > > There's no company behind this, just myself. Great, it's your copyright, be proud, put it on there! > > > + > > > +#include <linux/bitfield.h> > > > +#include <linux/bits.h> > > > +#include <linux/console.h> > > > +#include <linux/delay.h> > > > +#include <linux/io.h> > > > +#include <linux/irq.h> > > > +#include <linux/module.h> > > > +#include <linux/of.h> > > > +#include <linux/of_device.h> > > > +#include <linux/serial_core.h> > > > +#include <linux/slab.h> > > > +#include <linux/tty_flip.h> > > > +#include <asm/serial.h> > > > + > > > +#define DRIVER_NAME "esp32s3-acm" > > > +#define DEV_NAME "ttyACM" > > > > There is already a ttyACM driver in the kernel, will this conflict with > > that one? And are you using the same major/minor numbers for it as > > well? If so, how is this going to work? > > I'll rename it to ttyS. I see that it coexists with the other driver that calls > its devices ttyS just fine. Great. But if you are going to be like a ACM gadget, use ttyGS like that driver does? > > > +static void esp32s3_acm_set_mctrl(struct uart_port *port, unsigned int mctrl) > > > +{ > > > +} > > > > Do you have to have empty functions for callbacks that do nothing? > > The serial core has unconditional calls to these callbacks. Ah, good catch, maybe we should fix up the serial core. > > > --- a/include/uapi/linux/serial_core.h > > > +++ b/include/uapi/linux/serial_core.h > > > @@ -248,4 +248,7 @@ > > > /* Espressif ESP32 UART */ > > > #define PORT_ESP32UART 124 > > > > > > +/* Espressif ESP32 ACM */ > > > +#define PORT_ESP32ACM 125 > > > > Why are these defines needed? What in userspace is going to require > > them? If nothing, please do not add them. > > I don't understand what the alternatives are. The comment for the > uart_ops::config_port() callback says that port->type should be set > to the type of the port found, and I see that almost every serial driver > defines a unique PORT_* for that. Yes, but not all do. If you don't need to do anything special, it can just claim to be a normal device, we've had threads about this on the list before. If you don't need to determine in userspace from the tty connection what device it is, just use the default one instead. thanks, greg k-h
On Thu, Oct 05, 2023 at 02:21:55PM -0700, Max Filippov wrote: > On Thu, Oct 5, 2023 at 11:57 AM Greg Kroah-Hartman > > > > > --- /dev/null > > > > > +++ b/drivers/tty/serial/esp32_acm.c > > > > > @@ -0,0 +1,459 @@ > > > > > +// SPDX-License-Identifier: GPL-2.0-or-later > > > > > > > > Why "or later"? I have to ask, sorry. > > > > > > I don't really have a preference here. Is there a reason to choose > > > GPL-2.0 only for a new code? > > > > It's your call, you need to pick that, but I can provide recommendations > > if you want :) > > Please do? If you only want your code being used in Linux, then stick with "GPL-2.0". If you want your code to be able to be copied into other GPLv3 licensed code bodies (like Hurd and others), then license it as "GPL-2.0-or-later". Your call. > > > > And no copyright information? That's fine, but be sure your company's > > > > lawyers are ok with it... > > > > > > There's no company behind this, just myself. > > > > Great, it's your copyright, be proud, put it on there! > > If I don't have to I'd rather not. This is just a piece of meaningless noise. You already own the copyright by virtue of creating the code (you can't give it away), so might as well put your mark on it to make it more noticable. But it's not required, if you don't want to, no one can force you, again, your call. > > > > > --- a/include/uapi/linux/serial_core.h > > > > > +++ b/include/uapi/linux/serial_core.h > > > > > @@ -248,4 +248,7 @@ > > > > > /* Espressif ESP32 UART */ > > > > > #define PORT_ESP32UART 124 > > > > > > > > > > +/* Espressif ESP32 ACM */ > > > > > +#define PORT_ESP32ACM 125 > > > > > > > > Why are these defines needed? What in userspace is going to require > > > > them? If nothing, please do not add them. > > > > > > I don't understand what the alternatives are. The comment for the > > > uart_ops::config_port() callback says that port->type should be set > > > to the type of the port found, and I see that almost every serial driver > > > defines a unique PORT_* for that. > > > > Yes, but not all do. If you don't need to do anything special, it can > > just claim to be a normal device, we've had threads about this on the > > list before. If you don't need to determine in userspace from the tty > > connection what device it is, just use the default one instead. > > Ok, it looks like having > > #define PORT_ESP32ACM (-1) > > in the driver source should be ok? I've tested that it works. Hah, I like that hack. But why not just use PORT_UNKNOWN? thanks, greg k-h
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index d9ca6b268f01..85807db8f7ce 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -1591,6 +1591,20 @@ config SERIAL_ESP32 earlycon=esp32s3uart,mmio32,0x60000000,115200n8,40000000 earlycon=esp32uart,mmio32,0x3ff40000,115200n8 +config SERIAL_ESP32_ACM + tristate "Espressif ESP32 USB ACM support" + depends on XTENSA_PLATFORM_ESP32 || (COMPILE_TEST && OF) + select SERIAL_CORE + select SERIAL_CORE_CONSOLE + select SERIAL_EARLYCON + help + Driver for the CDC ACM controllers of the Espressif ESP32S3 SoCs + that share separate USB controller with the JTAG adapter. + The device name used for this controller is ttyACM. + When earlycon option is enabled the following kernel command line + snippet may be used: + earlycon=esp32s3acm,mmio32,0x60038000 + endmenu config SERIAL_MCTRL_GPIO diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile index 7b73137df7f3..970a292ca418 100644 --- a/drivers/tty/serial/Makefile +++ b/drivers/tty/serial/Makefile @@ -89,6 +89,7 @@ obj-$(CONFIG_SERIAL_SIFIVE) += sifive.o obj-$(CONFIG_SERIAL_LITEUART) += liteuart.o obj-$(CONFIG_SERIAL_SUNPLUS) += sunplus-uart.o obj-$(CONFIG_SERIAL_ESP32) += esp32_uart.o +obj-$(CONFIG_SERIAL_ESP32_ACM) += esp32_acm.o # GPIOLIB helpers for modem control lines obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o diff --git a/drivers/tty/serial/esp32_acm.c b/drivers/tty/serial/esp32_acm.c new file mode 100644 index 000000000000..f02abd2ac65e --- /dev/null +++ b/drivers/tty/serial/esp32_acm.c @@ -0,0 +1,459 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +#include <linux/bitfield.h> +#include <linux/bits.h> +#include <linux/console.h> +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/serial_core.h> +#include <linux/slab.h> +#include <linux/tty_flip.h> +#include <asm/serial.h> + +#define DRIVER_NAME "esp32s3-acm" +#define DEV_NAME "ttyACM" +#define UART_NR 4 + +#define ESP32S3_ACM_TX_FIFO_SIZE 64 + +#define USB_SERIAL_JTAG_EP1_REG 0x00 +#define USB_SERIAL_JTAG_EP1_CONF_REG 0x04 +#define USB_SERIAL_JTAG_WR_DONE BIT(0) +#define USB_SERIAL_JTAG_SERIAL_IN_EP_DATA_FREE BIT(1) +#define USB_SERIAL_JTAG_INT_ST_REG 0x0c +#define USB_SERIAL_JTAG_SERIAL_OUT_RECV_PKT_INT_ST BIT(2) +#define USB_SERIAL_JTAG_SERIAL_IN_EMPTY_INT_ST BIT(3) +#define USB_SERIAL_JTAG_INT_ENA_REG 0x10 +#define USB_SERIAL_JTAG_SERIAL_OUT_RECV_PKT_INT_ENA BIT(2) +#define USB_SERIAL_JTAG_SERIAL_IN_EMPTY_INT_ENA BIT(3) +#define USB_SERIAL_JTAG_INT_CLR_REG 0x14 +#define USB_SERIAL_JTAG_IN_EP1_ST_REG 0x2c +#define USB_SERIAL_JTAG_IN_EP1_WR_ADDR GENMASK(8, 2) +#define USB_SERIAL_JTAG_OUT_EP1_ST_REG 0x3c +#define USB_SERIAL_JTAG_OUT_EP1_REC_DATA_CNT GENMASK(22, 16) + +static const struct of_device_id esp32s3_acm_dt_ids[] = { + { + .compatible = "esp,esp32s3-acm", + }, { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, esp32s3_acm_dt_ids); + +static struct uart_port *esp32s3_acm_ports[UART_NR]; + +static void esp32s3_acm_write(struct uart_port *port, unsigned long reg, u32 v) +{ + writel(v, port->membase + reg); +} + +static u32 esp32s3_acm_read(struct uart_port *port, unsigned long reg) +{ + return readl(port->membase + reg); +} + +static u32 esp32s3_acm_tx_fifo_free(struct uart_port *port) +{ + u32 status = esp32s3_acm_read(port, USB_SERIAL_JTAG_EP1_CONF_REG); + + return status & USB_SERIAL_JTAG_SERIAL_IN_EP_DATA_FREE; +} + +static u32 esp32s3_acm_tx_fifo_cnt(struct uart_port *port) +{ + u32 status = esp32s3_acm_read(port, USB_SERIAL_JTAG_IN_EP1_ST_REG); + + return FIELD_GET(USB_SERIAL_JTAG_IN_EP1_WR_ADDR, status); +} + +static u32 esp32s3_acm_rx_fifo_cnt(struct uart_port *port) +{ + u32 status = esp32s3_acm_read(port, USB_SERIAL_JTAG_OUT_EP1_ST_REG); + + return FIELD_GET(USB_SERIAL_JTAG_OUT_EP1_REC_DATA_CNT, status); +} + +/* return TIOCSER_TEMT when transmitter is not busy */ +static unsigned int esp32s3_acm_tx_empty(struct uart_port *port) +{ + return esp32s3_acm_tx_fifo_cnt(port) == 0 ? TIOCSER_TEMT : 0; +} + +static void esp32s3_acm_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ +} + +static unsigned int esp32s3_acm_get_mctrl(struct uart_port *port) +{ + return TIOCM_CAR; +} + +static void esp32s3_acm_stop_tx(struct uart_port *port) +{ + u32 int_ena; + + int_ena = esp32s3_acm_read(port, USB_SERIAL_JTAG_INT_ENA_REG); + int_ena &= ~USB_SERIAL_JTAG_SERIAL_IN_EMPTY_INT_ENA; + esp32s3_acm_write(port, USB_SERIAL_JTAG_INT_ENA_REG, int_ena); +} + +static void esp32s3_acm_rxint(struct uart_port *port) +{ + struct tty_port *tty_port = &port->state->port; + u32 rx_fifo_cnt = esp32s3_acm_rx_fifo_cnt(port); + unsigned long flags; + u32 i; + + if (!rx_fifo_cnt) + return; + + spin_lock_irqsave(&port->lock, flags); + + for (i = 0; i < rx_fifo_cnt; ++i) { + u32 rx = esp32s3_acm_read(port, USB_SERIAL_JTAG_EP1_REG); + + ++port->icount.rx; + tty_insert_flip_char(tty_port, rx, TTY_NORMAL); + } + spin_unlock_irqrestore(&port->lock, flags); + + tty_flip_buffer_push(tty_port); +} + +static void esp32s3_acm_push(struct uart_port *port) +{ + if (esp32s3_acm_tx_fifo_free(port)) + esp32s3_acm_write(port, USB_SERIAL_JTAG_EP1_CONF_REG, + USB_SERIAL_JTAG_WR_DONE); +} + +static void esp32s3_acm_put_char(struct uart_port *port, u8 c) +{ + esp32s3_acm_write(port, USB_SERIAL_JTAG_EP1_REG, c); +} + +static void esp32s3_acm_put_char_sync(struct uart_port *port, u8 c) +{ + unsigned long timeout = jiffies + HZ; + + while (!esp32s3_acm_tx_fifo_free(port)) { + if (time_after(jiffies, timeout)) { + dev_warn(port->dev, "timeout waiting for TX FIFO\n"); + return; + } + cpu_relax(); + } + esp32s3_acm_put_char(port, c); + esp32s3_acm_push(port); +} + +static void esp32s3_acm_transmit_buffer(struct uart_port *port) +{ + u32 tx_fifo_used; + unsigned int pending; + u8 ch; + + if (!esp32s3_acm_tx_fifo_free(port)) + return; + + tx_fifo_used = esp32s3_acm_tx_fifo_cnt(port); + pending = uart_port_tx_limited(port, ch, + ESP32S3_ACM_TX_FIFO_SIZE - tx_fifo_used, + true, esp32s3_acm_put_char(port, ch), + ({})); + if (pending) { + u32 int_ena; + + int_ena = esp32s3_acm_read(port, USB_SERIAL_JTAG_INT_ENA_REG); + int_ena |= USB_SERIAL_JTAG_SERIAL_IN_EMPTY_INT_ENA; + esp32s3_acm_write(port, USB_SERIAL_JTAG_INT_ENA_REG, int_ena); + } + esp32s3_acm_push(port); +} + +static void esp32s3_acm_txint(struct uart_port *port) +{ + esp32s3_acm_transmit_buffer(port); +} + +static irqreturn_t esp32s3_acm_int(int irq, void *dev_id) +{ + struct uart_port *port = dev_id; + u32 status; + + status = esp32s3_acm_read(port, USB_SERIAL_JTAG_INT_ST_REG); + esp32s3_acm_write(port, USB_SERIAL_JTAG_INT_CLR_REG, status); + + if (status & USB_SERIAL_JTAG_SERIAL_OUT_RECV_PKT_INT_ST) + esp32s3_acm_rxint(port); + if (status & USB_SERIAL_JTAG_SERIAL_IN_EMPTY_INT_ST) + esp32s3_acm_txint(port); + + return IRQ_RETVAL(status); +} + +static void esp32s3_acm_start_tx(struct uart_port *port) +{ + esp32s3_acm_transmit_buffer(port); +} + +static void esp32s3_acm_stop_rx(struct uart_port *port) +{ + u32 int_ena; + + int_ena = esp32s3_acm_read(port, USB_SERIAL_JTAG_INT_ENA_REG); + int_ena &= ~USB_SERIAL_JTAG_SERIAL_OUT_RECV_PKT_INT_ENA; + esp32s3_acm_write(port, USB_SERIAL_JTAG_INT_ENA_REG, int_ena); +} + +static int esp32s3_acm_startup(struct uart_port *port) +{ + int ret; + + ret = request_irq(port->irq, esp32s3_acm_int, 0, DRIVER_NAME, port); + if (ret) + return ret; + esp32s3_acm_write(port, USB_SERIAL_JTAG_INT_ENA_REG, + USB_SERIAL_JTAG_SERIAL_OUT_RECV_PKT_INT_ENA); + + return 0; +} + +static void esp32s3_acm_shutdown(struct uart_port *port) +{ + esp32s3_acm_write(port, USB_SERIAL_JTAG_INT_ENA_REG, 0); + free_irq(port->irq, port); +} + +static void esp32s3_acm_set_termios(struct uart_port *port, + struct ktermios *termios, + const struct ktermios *old) +{ +} + +static const char *esp32s3_acm_type(struct uart_port *port) +{ + return "ESP32S3 ACM"; +} + +/* configure/auto-configure the port */ +static void esp32s3_acm_config_port(struct uart_port *port, int flags) +{ + if (flags & UART_CONFIG_TYPE) + port->type = PORT_ESP32ACM; +} + +#ifdef CONFIG_CONSOLE_POLL +static void esp32s3_acm_poll_put_char(struct uart_port *port, unsigned char c) +{ + esp32s3_acm_put_char_sync(port, c); +} + +static int esp32s3_acm_poll_get_char(struct uart_port *port) +{ + if (esp32s3_acm_rx_fifo_cnt(port)) + return esp32s3_acm_read(port, USB_SERIAL_JTAG_EP1_REG); + else + return NO_POLL_CHAR; +} +#endif + +static const struct uart_ops esp32s3_acm_pops = { + .tx_empty = esp32s3_acm_tx_empty, + .set_mctrl = esp32s3_acm_set_mctrl, + .get_mctrl = esp32s3_acm_get_mctrl, + .stop_tx = esp32s3_acm_stop_tx, + .start_tx = esp32s3_acm_start_tx, + .stop_rx = esp32s3_acm_stop_rx, + .startup = esp32s3_acm_startup, + .shutdown = esp32s3_acm_shutdown, + .set_termios = esp32s3_acm_set_termios, + .type = esp32s3_acm_type, + .config_port = esp32s3_acm_config_port, +#ifdef CONFIG_CONSOLE_POLL + .poll_put_char = esp32s3_acm_poll_put_char, + .poll_get_char = esp32s3_acm_poll_get_char, +#endif +}; + +static void esp32s3_acm_string_write(struct uart_port *port, const char *s, + unsigned int count) +{ + uart_console_write(port, s, count, esp32s3_acm_put_char_sync); +} + +static void +esp32s3_acm_console_write(struct console *co, const char *s, unsigned int count) +{ + struct uart_port *port = esp32s3_acm_ports[co->index]; + unsigned long flags; + bool locked = true; + + if (port->sysrq) + locked = false; + else if (oops_in_progress) + locked = spin_trylock_irqsave(&port->lock, flags); + else + spin_lock_irqsave(&port->lock, flags); + + esp32s3_acm_string_write(port, s, count); + + if (locked) + spin_unlock_irqrestore(&port->lock, flags); +} + +static struct uart_driver esp32s3_acm_reg; +static struct console esp32s3_acm_console = { + .name = DEV_NAME, + .write = esp32s3_acm_console_write, + .device = uart_console_device, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &esp32s3_acm_reg, +}; + +static void esp32s3_acm_earlycon_write(struct console *con, const char *s, + unsigned int n) +{ + struct earlycon_device *dev = con->data; + + uart_console_write(&dev->port, s, n, esp32s3_acm_put_char_sync); +} + +#ifdef CONFIG_CONSOLE_POLL +static int esp32s3_acm_earlycon_read(struct console *con, char *s, unsigned int n) +{ + struct earlycon_device *dev = con->data; + unsigned int num_read = 0; + + while (num_read < n) { + int c = esp32s3_acm_poll_get_char(&dev->port); + + if (c == NO_POLL_CHAR) + break; + s[num_read++] = c; + } + return num_read; +} +#endif + +static int __init esp32s3_acm_early_console_setup(struct earlycon_device *device, + const char *options) +{ + if (!device->port.membase) + return -ENODEV; + + device->con->write = esp32s3_acm_earlycon_write; +#ifdef CONFIG_CONSOLE_POLL + device->con->read = esp32s3_acm_earlycon_read; +#endif + return 0; +} + +OF_EARLYCON_DECLARE(esp32s3acm, "esp,esp32s3-acm", + esp32s3_acm_early_console_setup); + +static struct uart_driver esp32s3_acm_reg = { + .owner = THIS_MODULE, + .driver_name = DRIVER_NAME, + .dev_name = DEV_NAME, + .nr = ARRAY_SIZE(esp32s3_acm_ports), + .cons = &esp32s3_acm_console, +}; + +static int esp32s3_acm_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct uart_port *port; + struct resource *res; + int ret; + + port = devm_kzalloc(&pdev->dev, sizeof(*port), GFP_KERNEL); + if (!port) + return -ENOMEM; + + ret = of_alias_get_id(np, "serial"); + if (ret < 0) { + dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret); + return ret; + } + if (ret >= UART_NR) { + dev_err(&pdev->dev, "driver limited to %d serial ports\n", + UART_NR); + return -ENOMEM; + } + + port->line = ret; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + + port->mapbase = res->start; + port->membase = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(port->membase)) + return PTR_ERR(port->membase); + + port->dev = &pdev->dev; + port->type = PORT_ESP32ACM; + port->iotype = UPIO_MEM; + port->irq = platform_get_irq(pdev, 0); + port->ops = &esp32s3_acm_pops; + port->flags = UPF_BOOT_AUTOCONF; + port->has_sysrq = 1; + port->fifosize = ESP32S3_ACM_TX_FIFO_SIZE; + + esp32s3_acm_ports[port->line] = port; + + platform_set_drvdata(pdev, port); + + return uart_add_one_port(&esp32s3_acm_reg, port); +} + +static int esp32s3_acm_remove(struct platform_device *pdev) +{ + struct uart_port *port = platform_get_drvdata(pdev); + + uart_remove_one_port(&esp32s3_acm_reg, port); + return 0; +} + + +static struct platform_driver esp32s3_acm_driver = { + .probe = esp32s3_acm_probe, + .remove = esp32s3_acm_remove, + .driver = { + .name = DRIVER_NAME, + .of_match_table = esp32s3_acm_dt_ids, + }, +}; + +static int __init esp32s3_acm_init(void) +{ + int ret; + + ret = uart_register_driver(&esp32s3_acm_reg); + if (ret) + return ret; + + ret = platform_driver_register(&esp32s3_acm_driver); + if (ret) + uart_unregister_driver(&esp32s3_acm_reg); + + return ret; +} + +static void __exit esp32s3_acm_exit(void) +{ + platform_driver_unregister(&esp32s3_acm_driver); + uart_unregister_driver(&esp32s3_acm_reg); +} + +module_init(esp32s3_acm_init); +module_exit(esp32s3_acm_exit); + +MODULE_AUTHOR("Max Filippov <jcmvbkbc@gmail.com>"); +MODULE_LICENSE("GPL"); diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h index ff076d6be159..1045bf096837 100644 --- a/include/uapi/linux/serial_core.h +++ b/include/uapi/linux/serial_core.h @@ -248,4 +248,7 @@ /* Espressif ESP32 UART */ #define PORT_ESP32UART 124 +/* Espressif ESP32 ACM */ +#define PORT_ESP32ACM 125 + #endif /* _UAPILINUX_SERIAL_CORE_H */
Add driver for the ACM controller of the Espressif ESP32S3 Soc. Hardware specification is available at the following URL: https://www.espressif.com/sites/default/files/documentation/esp32-s3_technical_reference_manual_en.pdf (Chapter 33 USB Serial/JTAG Controller) Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> --- Changes v2->v3: - use HZ instead of msecs_to_jiffies(1000) in esp32_acm_put_char_sync - add early return to esp32_acm_transmit_buffer - use request_irq/free_irq instead of devm_* versions Changes v1->v2: - redefine register fields using BIT and GENMASK - drop _MASK suffix from register field definitions - drop *_SHIFT definitions where possible - split register reads/writes and bitwise operations into multiple lines - use u8 instead of unsigned char in internal functions - add timeout to esp32_acm_put_char_sync - use uart_port_tx_limited in esp32_acm_transmit_buffer - use IRQ_RETVAL in esp32_acm_int - drop esp32s3_acm_console_putchar and esp32s3_acm_earlycon_putchar - turn num_read into unsigned int in esp32_acm_earlycon_read - drop MODULE_DESCRIPTION drivers/tty/serial/Kconfig | 14 + drivers/tty/serial/Makefile | 1 + drivers/tty/serial/esp32_acm.c | 459 +++++++++++++++++++++++++++++++ include/uapi/linux/serial_core.h | 3 + 4 files changed, 477 insertions(+) create mode 100644 drivers/tty/serial/esp32_acm.c