From cf066f9334b9632ca1a8185118083a9218504e0a Mon Sep 17 00:00:00 2001 From: "Jiri Slaby (SUSE)" Date: Mon, 22 Jan 2024 12:04:01 +0100 Subject: Documentation: add console.rst Now, that the console kernel-doc is in better shape, include it in the tty/ docs. It's not supernice, but it is what it is. At least for the beginning. Signed-off-by: "Jiri Slaby (SUSE)" Cc: Jonathan Corbet Cc: linux-doc@vger.kernel.org Tested-by: Helge Deller # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-48-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman --- Documentation/driver-api/tty/console.rst | 45 ++++++++++++++++++++++++++++++++ Documentation/driver-api/tty/index.rst | 1 + 2 files changed, 46 insertions(+) create mode 100644 Documentation/driver-api/tty/console.rst (limited to 'Documentation') diff --git a/Documentation/driver-api/tty/console.rst b/Documentation/driver-api/tty/console.rst new file mode 100644 index 000000000000..4348e36cd33b --- /dev/null +++ b/Documentation/driver-api/tty/console.rst @@ -0,0 +1,45 @@ +.. SPDX-License-Identifier: GPL-2.0 + +======= +Console +======= + +.. contents:: :local: + +Struct Console +============== + +.. kernel-doc:: include/linux/console.h + :identifiers: console cons_flags + +Internals +--------- + +.. kernel-doc:: include/linux/console.h + :identifiers: nbcon_state nbcon_prio nbcon_context nbcon_write_context + +Struct Consw +============ + +.. kernel-doc:: include/linux/console.h + :identifiers: consw + +Console functions +================= + +.. kernel-doc:: include/linux/console.h + :identifiers: console_srcu_read_flags console_srcu_write_flags + console_is_registered for_each_console_srcu for_each_console + +.. kernel-doc:: drivers/tty/vt/selection.c + :export: +.. kernel-doc:: drivers/tty/vt/vt.c + :export: + +Internals +--------- + +.. kernel-doc:: drivers/tty/vt/selection.c + :internal: +.. kernel-doc:: drivers/tty/vt/vt.c + :internal: diff --git a/Documentation/driver-api/tty/index.rst b/Documentation/driver-api/tty/index.rst index b490da11f257..c1ffe3d1ec46 100644 --- a/Documentation/driver-api/tty/index.rst +++ b/Documentation/driver-api/tty/index.rst @@ -38,6 +38,7 @@ In-detail description of the named TTY structures is in separate documents: tty_buffer tty_ioctl tty_internals + console Writing TTY Driver ================== -- cgit v1.2.3-70-g09d2 From 1d3f02abd551c69c6a82b9f22430b497b0bf7c55 Mon Sep 17 00:00:00 2001 From: Tudor Ambarus Date: Fri, 19 Jan 2024 10:45:09 +0000 Subject: dt-bindings: serial: samsung: do not allow reg-io-width for gs101 All gs101 serial ports are restricted to 32-bit register accesses. This requirement will be inferred from the compatible. Do not allow the reg-io-width property for the google,gs101-uart compatible. Suggested-by: Krzysztof Kozlowski Reviewed-by: Krzysztof Kozlowski Reviewed-by: Peter Griffin Signed-off-by: Tudor Ambarus Reviewed-by: Sam Protsenko Link: https://lore.kernel.org/r/20240119104526.1221243-3-tudor.ambarus@linaro.org Signed-off-by: Greg Kroah-Hartman --- Documentation/devicetree/bindings/serial/samsung_uart.yaml | 2 ++ 1 file changed, 2 insertions(+) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/serial/samsung_uart.yaml b/Documentation/devicetree/bindings/serial/samsung_uart.yaml index 133259ed3a34..0f0131026911 100644 --- a/Documentation/devicetree/bindings/serial/samsung_uart.yaml +++ b/Documentation/devicetree/bindings/serial/samsung_uart.yaml @@ -143,6 +143,8 @@ allOf: then: required: - samsung,uart-fifosize + properties: + reg-io-width: false unevaluatedProperties: false -- cgit v1.2.3-70-g09d2 From 09aec324b60f4309eeba8d2d5c897e882cce23bc Mon Sep 17 00:00:00 2001 From: Peng Fan Date: Sun, 21 Jan 2024 19:53:01 +0800 Subject: dt-bindings: serial: fsl-lpuart: support i.MX95 Add i.MX95 compatible string. Same as i.MX93, it is compatible with i.MX8ULP. Signed-off-by: Peng Fan Acked-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20240121115301.1420502-1-peng.fan@oss.nxp.com Signed-off-by: Greg Kroah-Hartman --- Documentation/devicetree/bindings/serial/fsl-lpuart.yaml | 1 + 1 file changed, 1 insertion(+) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/serial/fsl-lpuart.yaml b/Documentation/devicetree/bindings/serial/fsl-lpuart.yaml index 3a5b59f5d3e3..3f9ace89dee9 100644 --- a/Documentation/devicetree/bindings/serial/fsl-lpuart.yaml +++ b/Documentation/devicetree/bindings/serial/fsl-lpuart.yaml @@ -30,6 +30,7 @@ properties: - items: - enum: - fsl,imx93-lpuart + - fsl,imx95-lpuart - const: fsl,imx8ulp-lpuart - const: fsl,imx7ulp-lpuart - items: -- cgit v1.2.3-70-g09d2 From d2a2a5602cfe7fed309c81135b5ecb62556ce89b Mon Sep 17 00:00:00 2001 From: Nghia Nguyen Date: Wed, 24 Jan 2024 12:27:15 +0100 Subject: dt-bindings: serial: renesas,hscif: Document r8a779h0 bindings The R-Car V4M (R8A779H0) SoC has R-Car Gen4 compatible HSCIF ports, so document the SoC-specific bindings. Signed-off-by: Nghia Nguyen Signed-off-by: Geert Uytterhoeven Reviewed-by: Wolfram Sang Acked-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/55b458e0ba9824e1246e556075bf882032c37279.1706095578.git.geert@linux-m68k.org Signed-off-by: Greg Kroah-Hartman --- Documentation/devicetree/bindings/serial/renesas,hscif.yaml | 1 + 1 file changed, 1 insertion(+) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/serial/renesas,hscif.yaml b/Documentation/devicetree/bindings/serial/renesas,hscif.yaml index 2046e2dc0a3d..9480ed30915c 100644 --- a/Documentation/devicetree/bindings/serial/renesas,hscif.yaml +++ b/Documentation/devicetree/bindings/serial/renesas,hscif.yaml @@ -59,6 +59,7 @@ properties: - renesas,hscif-r8a779a0 # R-Car V3U - renesas,hscif-r8a779f0 # R-Car S4-8 - renesas,hscif-r8a779g0 # R-Car V4H + - renesas,hscif-r8a779h0 # R-Car V4M - const: renesas,rcar-gen4-hscif # R-Car Gen4 - const: renesas,hscif # generic HSCIF compatible UART -- cgit v1.2.3-70-g09d2 From 32152467ffac3b79eae7313959c310946b0e6072 Mon Sep 17 00:00:00 2001 From: Manikanta Guntupalli Date: Tue, 23 Jan 2024 11:46:53 +0530 Subject: dt-bindings: Add reference to rs485.yaml Xilinx/AMD Kria SOM KD240 board has a rs485 compatible peripheral. Update the binding to have rs485 support. Acked-by: Conor Dooley Signed-off-by: Manikanta Guntupalli Link: https://lore.kernel.org/r/20240123061655.2150946-2-manikanta.guntupalli@amd.com Signed-off-by: Greg Kroah-Hartman --- Documentation/devicetree/bindings/serial/cdns,uart.yaml | 1 + 1 file changed, 1 insertion(+) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/serial/cdns,uart.yaml b/Documentation/devicetree/bindings/serial/cdns,uart.yaml index e35ad1109efc..2129247d7c81 100644 --- a/Documentation/devicetree/bindings/serial/cdns,uart.yaml +++ b/Documentation/devicetree/bindings/serial/cdns,uart.yaml @@ -55,6 +55,7 @@ required: allOf: - $ref: serial.yaml# + - $ref: rs485.yaml# - if: properties: compatible: -- cgit v1.2.3-70-g09d2 From 12d2a81c57042337b68ef7d1b400a6f2b707dc94 Mon Sep 17 00:00:00 2001 From: Christoph Winklhofer Date: Fri, 9 Feb 2024 07:22:37 +0100 Subject: dt-bindings: serial: allow onewire as child node The UART 1-Wire bus utilizes the Serial Device Bus to create the 1-wire timing patterns. Acked-by: Rob Herring Signed-off-by: Christoph Winklhofer Link: https://lore.kernel.org/r/20240209-w1-uart-v6-1-3e753c149196@gmail.com Signed-off-by: Krzysztof Kozlowski --- Documentation/devicetree/bindings/serial/serial.yaml | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/serial/serial.yaml b/Documentation/devicetree/bindings/serial/serial.yaml index 65804ca274ae..ffc9198ae214 100644 --- a/Documentation/devicetree/bindings/serial/serial.yaml +++ b/Documentation/devicetree/bindings/serial/serial.yaml @@ -88,7 +88,7 @@ properties: TX FIFO threshold configuration (in bytes). patternProperties: - "^(bluetooth|bluetooth-gnss|gnss|gps|mcu)$": + "^(bluetooth|bluetooth-gnss|gnss|gps|mcu|onewire)$": if: type: object then: -- cgit v1.2.3-70-g09d2 From 23b333375317f6c2866e1ede7e7c4a726fc22aa8 Mon Sep 17 00:00:00 2001 From: Christoph Winklhofer Date: Fri, 9 Feb 2024 07:22:38 +0100 Subject: dt-bindings: w1: UART 1-Wire bus Add device tree binding for UART 1-Wire bus. Reviewed-by: Rob Herring Signed-off-by: Christoph Winklhofer Link: https://lore.kernel.org/r/20240209-w1-uart-v6-2-3e753c149196@gmail.com Signed-off-by: Krzysztof Kozlowski --- Documentation/devicetree/bindings/w1/w1-uart.yaml | 59 +++++++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 Documentation/devicetree/bindings/w1/w1-uart.yaml (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/w1/w1-uart.yaml b/Documentation/devicetree/bindings/w1/w1-uart.yaml new file mode 100644 index 000000000000..bd7c62d780b8 --- /dev/null +++ b/Documentation/devicetree/bindings/w1/w1-uart.yaml @@ -0,0 +1,59 @@ +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/w1/w1-uart.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: UART 1-Wire Bus + +maintainers: + - Christoph Winklhofer + +description: | + UART 1-wire bus. Utilizes the UART interface via the Serial Device Bus + to create the 1-Wire timing patterns. + + The UART peripheral must support full-duplex and operate in open-drain + mode. The timing patterns are generated by a specific combination of + baud-rate and transmitted byte, which corresponds to a 1-Wire read bit, + write bit or reset pulse. + + The default baud-rate for reset and presence detection is 9600 and for + a 1-Wire read or write operation 115200. In case the actual baud-rate + is different from the requested one, the transmitted byte is adapted + to generate the 1-Wire timing patterns. + + https://www.analog.com/en/technical-articles/using-a-uart-to-implement-a-1wire-bus-master.html + +properties: + compatible: + const: w1-uart + + reset-bps: + default: 9600 + description: + The baud rate for the 1-Wire reset and presence detect. + + write-0-bps: + default: 115200 + description: + The baud rate for the 1-Wire write-0 cycle. + + write-1-bps: + default: 115200 + description: + The baud rate for the 1-Wire write-1 and read cycle. + +required: + - compatible + +additionalProperties: + type: object + +examples: + - | + serial { + onewire { + compatible = "w1-uart"; + }; + }; -- cgit v1.2.3-70-g09d2 From a3c08804364e80328a9ffdac59bb26676b938195 Mon Sep 17 00:00:00 2001 From: Christoph Winklhofer Date: Wed, 14 Feb 2024 07:36:15 +0100 Subject: w1: add UART w1 bus driver Add a UART 1-Wire bus driver. The driver utilizes the UART interface via the Serial Device Bus to create the 1-Wire timing patterns. The driver was tested on a "Raspberry Pi 3B" with a DS18B20 and on a "Variscite DART-6UL" with a DS18S20 temperature sensor. The 1-Wire timing pattern and the corresponding UART baud-rate with the interpretation of the transferred bytes are described in the document: Link: https://www.analog.com/en/technical-articles/using-a-uart-to-implement-a-1wire-bus-master.html In short, the UART peripheral must support full-duplex and operate in open-drain mode. The timing patterns are generated by a specific combination of baud-rate and transmitted byte, which corresponds to a 1-Wire read bit, write bit or reset. Signed-off-by: Christoph Winklhofer Link: https://lore.kernel.org/r/20240214-w1-uart-v7-3-6e21fa24e066@gmail.com [krzysztof: w1_uart_serdev_receive_buf() return type fixup] Signed-off-by: Krzysztof Kozlowski --- Documentation/w1/masters/index.rst | 1 + Documentation/w1/masters/w1-uart.rst | 54 +++++ drivers/w1/masters/Kconfig | 10 + drivers/w1/masters/Makefile | 1 + drivers/w1/masters/w1-uart.c | 415 +++++++++++++++++++++++++++++++++++ 5 files changed, 481 insertions(+) create mode 100644 Documentation/w1/masters/w1-uart.rst create mode 100644 drivers/w1/masters/w1-uart.c (limited to 'Documentation') diff --git a/Documentation/w1/masters/index.rst b/Documentation/w1/masters/index.rst index 4442a98850ad..cc40189909fd 100644 --- a/Documentation/w1/masters/index.rst +++ b/Documentation/w1/masters/index.rst @@ -12,3 +12,4 @@ mxc-w1 omap-hdq w1-gpio + w1-uart diff --git a/Documentation/w1/masters/w1-uart.rst b/Documentation/w1/masters/w1-uart.rst new file mode 100644 index 000000000000..8d0f122178d4 --- /dev/null +++ b/Documentation/w1/masters/w1-uart.rst @@ -0,0 +1,54 @@ +.. SPDX-License-Identifier: GPL-2.0-or-later + +===================== +Kernel driver w1-uart +===================== + +Author: Christoph Winklhofer + + +Description +----------- + +UART 1-Wire bus driver. The driver utilizes the UART interface via the +Serial Device Bus to create the 1-Wire timing patterns as described in +the document `"Using a UART to Implement a 1-Wire Bus Master"`_. + +.. _"Using a UART to Implement a 1-Wire Bus Master": https://www.analog.com/en/technical-articles/using-a-uart-to-implement-a-1wire-bus-master.html + +In short, the UART peripheral must support full-duplex and operate in +open-drain mode. The timing patterns are generated by a specific +combination of baud-rate and transmitted byte, which corresponds to a +1-Wire read bit, write bit or reset pulse. + +For instance the timing pattern for a 1-Wire reset and presence detect uses +the baud-rate 9600, i.e. 104.2 us per bit. The transmitted byte 0xf0 over +UART (least significant bit first, start-bit low) sets the reset low time +for 1-Wire to 521 us. A present 1-Wire device changes the received byte by +pulling the line low, which is used by the driver to evaluate the result of +the 1-Wire operation. + +Similar for a 1-Wire read bit or write bit, which uses the baud-rate +115200, i.e. 8.7 us per bit. The transmitted byte 0x80 is used for a +Write-0 operation (low time 69.6us) and the byte 0xff for Read-0, Read-1 +and Write-1 (low time 8.7us). + +The default baud-rate for reset and presence detection is 9600 and for +a 1-Wire read or write operation 115200. In case the actual baud-rate +is different from the requested one, the transmitted byte is adapted +to generate the 1-Wire timing patterns. + + +Usage +----- + +Specify the UART 1-wire bus in the device tree by adding the single child +onewire to the serial node (e.g. uart0). For example: +:: + + @uart0 { + ... + onewire { + compatible = "w1-uart"; + }; + }; diff --git a/drivers/w1/masters/Kconfig b/drivers/w1/masters/Kconfig index 513c0b114337..e6049a75b35b 100644 --- a/drivers/w1/masters/Kconfig +++ b/drivers/w1/masters/Kconfig @@ -78,5 +78,15 @@ config W1_MASTER_SGI This support is also available as a module. If so, the module will be called sgi_w1. +config W1_MASTER_UART + tristate "UART 1-wire driver" + depends on SERIAL_DEV_BUS + help + Say Y here if you want to communicate with your 1-wire devices using + UART interface. + + This support is also available as a module. If so, the module + will be called w1-uart. + endmenu diff --git a/drivers/w1/masters/Makefile b/drivers/w1/masters/Makefile index 6c5a21f9b88c..227f80987e69 100644 --- a/drivers/w1/masters/Makefile +++ b/drivers/w1/masters/Makefile @@ -12,3 +12,4 @@ obj-$(CONFIG_W1_MASTER_MXC) += mxc_w1.o obj-$(CONFIG_W1_MASTER_GPIO) += w1-gpio.o obj-$(CONFIG_HDQ_MASTER_OMAP) += omap_hdq.o obj-$(CONFIG_W1_MASTER_SGI) += sgi_w1.o +obj-$(CONFIG_W1_MASTER_UART) += w1-uart.o diff --git a/drivers/w1/masters/w1-uart.c b/drivers/w1/masters/w1-uart.c new file mode 100644 index 000000000000..a31782e56ba7 --- /dev/null +++ b/drivers/w1/masters/w1-uart.c @@ -0,0 +1,415 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * w1-uart - UART 1-Wire bus driver + * + * Uses the UART interface (via Serial Device Bus) to create the 1-Wire + * timing patterns. Implements the following 1-Wire master interface: + * + * - reset_bus: requests baud-rate 9600 + * + * - touch_bit: requests baud-rate 115200 + * + * Author: Christoph Winklhofer + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +/* UART packet contains start and stop bit */ +#define W1_UART_BITS_PER_PACKET (BITS_PER_BYTE + 2) + +/* Timeout to wait for completion of serdev-receive */ +#define W1_UART_TIMEOUT msecs_to_jiffies(500) + +/** + * struct w1_uart_config - configuration for 1-Wire operation + * @baudrate: baud-rate returned from serdev + * @delay_us: delay to complete a 1-Wire cycle (in us) + * @tx_byte: byte to generate 1-Wire timing pattern + */ +struct w1_uart_config { + unsigned int baudrate; + unsigned int delay_us; + u8 tx_byte; +}; + +/** + * struct w1_uart_device - 1-Wire UART device structure + * @serdev: serial device + * @bus: w1-bus master + * @cfg_reset: config for 1-Wire reset + * @cfg_touch_0: config for 1-Wire write-0 cycle + * @cfg_touch_1: config for 1-Wire write-1 and read cycle + * @rx_byte_received: completion for serdev receive + * @rx_mutex: mutex to protect rx_err and rx_byte + * @rx_err: indicates an error in serdev-receive + * @rx_byte: result byte from serdev-receive + */ +struct w1_uart_device { + struct serdev_device *serdev; + struct w1_bus_master bus; + + struct w1_uart_config cfg_reset; + struct w1_uart_config cfg_touch_0; + struct w1_uart_config cfg_touch_1; + + struct completion rx_byte_received; + /* + * protect rx_err and rx_byte from concurrent access in + * w1-callbacks and serdev-receive. + */ + struct mutex rx_mutex; + int rx_err; + u8 rx_byte; +}; + +/** + * struct w1_uart_limits - limits for 1-Wire operations + * @baudrate: Requested baud-rate to create 1-Wire timing pattern + * @bit_min_us: minimum time for a bit (in us) + * @bit_max_us: maximum time for a bit (in us) + * @sample_us: timespan to sample 1-Wire response + * @cycle_us: duration of the 1-Wire cycle + */ +struct w1_uart_limits { + unsigned int baudrate; + unsigned int bit_min_us; + unsigned int bit_max_us; + unsigned int sample_us; + unsigned int cycle_us; +}; + +static inline unsigned int baud_to_bit_ns(unsigned int baud) +{ + return NSEC_PER_SEC / baud; +} + +static inline unsigned int to_ns(unsigned int us) +{ + return us * NSEC_PER_USEC; +} + +/* + * Set baud-rate, delay and tx-byte to create a 1-Wire pulse and adapt + * the tx-byte according to the actual baud-rate. + * + * Reject when: + * - time for a bit outside min/max range + * - a 1-Wire response is not detectable for sent byte + */ +static int w1_uart_set_config(struct serdev_device *serdev, + const struct w1_uart_limits *limits, + struct w1_uart_config *w1cfg) +{ + unsigned int packet_ns; + unsigned int bits_low; + unsigned int bit_ns; + unsigned int low_ns; + + w1cfg->baudrate = serdev_device_set_baudrate(serdev, limits->baudrate); + if (w1cfg->baudrate == 0) + return -EINVAL; + + /* Compute in nanoseconds for accuracy */ + bit_ns = baud_to_bit_ns(w1cfg->baudrate); + bits_low = to_ns(limits->bit_min_us) / bit_ns; + /* start bit is always low */ + low_ns = bit_ns * (bits_low + 1); + + if (low_ns < to_ns(limits->bit_min_us)) + return -EINVAL; + + if (low_ns > to_ns(limits->bit_max_us)) + return -EINVAL; + + /* 1-Wire response detectable for sent byte */ + if (limits->sample_us > 0 && + bit_ns * BITS_PER_BYTE < low_ns + to_ns(limits->sample_us)) + return -EINVAL; + + /* delay: 1-Wire cycle takes longer than the UART packet */ + packet_ns = bit_ns * W1_UART_BITS_PER_PACKET; + w1cfg->delay_us = 0; + if (to_ns(limits->cycle_us) > packet_ns) + w1cfg->delay_us = + (to_ns(limits->cycle_us) - packet_ns) / NSEC_PER_USEC; + + /* byte to create 1-Wire pulse */ + w1cfg->tx_byte = 0xff << bits_low; + + return 0; +} + +/* + * Configuration for reset and presence detect + * - bit_min_us is 480us, add margin and use 485us + * - limits for sample time 60us-75us, use 65us + */ +static int w1_uart_set_config_reset(struct w1_uart_device *w1dev) +{ + struct serdev_device *serdev = w1dev->serdev; + struct device_node *np = serdev->dev.of_node; + + struct w1_uart_limits limits = { .baudrate = 9600, + .bit_min_us = 485, + .bit_max_us = 640, + .sample_us = 65, + .cycle_us = 960 }; + + of_property_read_u32(np, "reset-bps", &limits.baudrate); + + return w1_uart_set_config(serdev, &limits, &w1dev->cfg_reset); +} + +/* + * Configuration for write-0 cycle (touch bit 0) + * - bit_min_us is 60us, add margin and use 65us + * - no sampling required, sample_us = 0 + */ +static int w1_uart_set_config_touch_0(struct w1_uart_device *w1dev) +{ + struct serdev_device *serdev = w1dev->serdev; + struct device_node *np = serdev->dev.of_node; + + struct w1_uart_limits limits = { .baudrate = 115200, + .bit_min_us = 65, + .bit_max_us = 120, + .sample_us = 0, + .cycle_us = 70 }; + + of_property_read_u32(np, "write-0-bps", &limits.baudrate); + + return w1_uart_set_config(serdev, &limits, &w1dev->cfg_touch_0); +} + +/* + * Configuration for write-1 and read cycle (touch bit 1) + * - bit_min_us is 5us, add margin and use 6us + * - limits for sample time 5us-15us, use 15us + */ +static int w1_uart_set_config_touch_1(struct w1_uart_device *w1dev) +{ + struct serdev_device *serdev = w1dev->serdev; + struct device_node *np = serdev->dev.of_node; + + struct w1_uart_limits limits = { .baudrate = 115200, + .bit_min_us = 6, + .bit_max_us = 15, + .sample_us = 15, + .cycle_us = 70 }; + + of_property_read_u32(np, "write-1-bps", &limits.baudrate); + + return w1_uart_set_config(serdev, &limits, &w1dev->cfg_touch_1); +} + +/* + * Configure and open the serial device + */ +static int w1_uart_serdev_open(struct w1_uart_device *w1dev) +{ + struct serdev_device *serdev = w1dev->serdev; + struct device *dev = &serdev->dev; + int ret; + + ret = devm_serdev_device_open(dev, serdev); + if (ret < 0) + return ret; + + ret = serdev_device_set_parity(serdev, SERDEV_PARITY_NONE); + if (ret < 0) { + dev_err(dev, "set parity failed\n"); + return ret; + } + + ret = w1_uart_set_config_reset(w1dev); + if (ret < 0) { + dev_err(dev, "config for reset failed\n"); + return ret; + } + + ret = w1_uart_set_config_touch_0(w1dev); + if (ret < 0) { + dev_err(dev, "config for touch-0 failed\n"); + return ret; + } + + ret = w1_uart_set_config_touch_1(w1dev); + if (ret < 0) { + dev_err(dev, "config for touch-1 failed\n"); + return ret; + } + + serdev_device_set_flow_control(serdev, false); + + return 0; +} + +/* + * Send one byte (tx_byte) and read one byte (rx_byte) via serdev. + */ +static int w1_uart_serdev_tx_rx(struct w1_uart_device *w1dev, + const struct w1_uart_config *w1cfg, u8 *rx_byte) +{ + struct serdev_device *serdev = w1dev->serdev; + int ret; + + serdev_device_write_flush(serdev); + serdev_device_set_baudrate(serdev, w1cfg->baudrate); + + /* write and immediately read one byte */ + reinit_completion(&w1dev->rx_byte_received); + ret = serdev_device_write_buf(serdev, &w1cfg->tx_byte, 1); + if (ret != 1) + return -EIO; + ret = wait_for_completion_interruptible_timeout( + &w1dev->rx_byte_received, W1_UART_TIMEOUT); + if (ret <= 0) + return -EIO; + + /* locking could fail when serdev is unexpectedly receiving. */ + if (!mutex_trylock(&w1dev->rx_mutex)) + return -EIO; + + ret = w1dev->rx_err; + if (ret == 0) + *rx_byte = w1dev->rx_byte; + + mutex_unlock(&w1dev->rx_mutex); + + if (w1cfg->delay_us > 0) + fsleep(w1cfg->delay_us); + + return ret; +} + +static size_t w1_uart_serdev_receive_buf(struct serdev_device *serdev, + const u8 *buf, size_t count) +{ + struct w1_uart_device *w1dev = serdev_device_get_drvdata(serdev); + + mutex_lock(&w1dev->rx_mutex); + + /* sent a single byte and receive one single byte */ + if (count == 1) { + w1dev->rx_byte = buf[0]; + w1dev->rx_err = 0; + } else { + w1dev->rx_err = -EIO; + } + + mutex_unlock(&w1dev->rx_mutex); + complete(&w1dev->rx_byte_received); + + return count; +} + +static const struct serdev_device_ops w1_uart_serdev_ops = { + .receive_buf = w1_uart_serdev_receive_buf, + .write_wakeup = serdev_device_write_wakeup, +}; + +/* + * 1-wire reset and presence detect: A present slave will manipulate + * the received byte by pulling the 1-Wire low. + */ +static u8 w1_uart_reset_bus(void *data) +{ + struct w1_uart_device *w1dev = data; + const struct w1_uart_config *w1cfg = &w1dev->cfg_reset; + int ret; + u8 val; + + ret = w1_uart_serdev_tx_rx(w1dev, w1cfg, &val); + if (ret < 0) + return -1; + + /* Device present (0) or no device (1) */ + return val != w1cfg->tx_byte ? 0 : 1; +} + +/* + * 1-Wire read and write cycle: Only the read-0 manipulates the + * received byte, all others left the line untouched. + */ +static u8 w1_uart_touch_bit(void *data, u8 bit) +{ + struct w1_uart_device *w1dev = data; + const struct w1_uart_config *w1cfg = bit ? &w1dev->cfg_touch_1 : + &w1dev->cfg_touch_0; + int ret; + u8 val; + + ret = w1_uart_serdev_tx_rx(w1dev, w1cfg, &val); + + /* return inactive bus state on error */ + if (ret < 0) + return 1; + + return val == w1cfg->tx_byte ? 1 : 0; +} + +static int w1_uart_probe(struct serdev_device *serdev) +{ + struct device *dev = &serdev->dev; + struct w1_uart_device *w1dev; + int ret; + + w1dev = devm_kzalloc(dev, sizeof(*w1dev), GFP_KERNEL); + if (!w1dev) + return -ENOMEM; + w1dev->bus.data = w1dev; + w1dev->bus.reset_bus = w1_uart_reset_bus; + w1dev->bus.touch_bit = w1_uart_touch_bit; + w1dev->serdev = serdev; + + init_completion(&w1dev->rx_byte_received); + mutex_init(&w1dev->rx_mutex); + + ret = w1_uart_serdev_open(w1dev); + if (ret < 0) + return ret; + serdev_device_set_drvdata(serdev, w1dev); + serdev_device_set_client_ops(serdev, &w1_uart_serdev_ops); + + return w1_add_master_device(&w1dev->bus); +} + +static void w1_uart_remove(struct serdev_device *serdev) +{ + struct w1_uart_device *w1dev = serdev_device_get_drvdata(serdev); + + /* + * Waits until w1-uart callbacks are finished, serdev is closed + * and its device data released automatically by devres (waits + * until serdev-receive is finished). + */ + w1_remove_master_device(&w1dev->bus); +} + +static const struct of_device_id w1_uart_of_match[] = { + { .compatible = "w1-uart" }, + {}, +}; +MODULE_DEVICE_TABLE(of, w1_uart_of_match); + +static struct serdev_device_driver w1_uart_driver = { + .driver = { + .name = "w1-uart", + .of_match_table = w1_uart_of_match, + }, + .probe = w1_uart_probe, + .remove = w1_uart_remove, +}; + +module_serdev_device_driver(w1_uart_driver); + +MODULE_DESCRIPTION("UART w1 bus driver"); +MODULE_AUTHOR("Christoph Winklhofer "); +MODULE_LICENSE("GPL"); -- cgit v1.2.3-70-g09d2 From 28e4c31e53151aef19ce61464e396ccc035903b6 Mon Sep 17 00:00:00 2001 From: Raphael Gallais-Pou Date: Mon, 26 Feb 2024 16:21:35 +0100 Subject: dt-bindings: serial: convert st,asc to DT schema 'clocks' property is required regarding the device. Convert st,asc binding to DT schema format in order to add this property, and update example. Signed-off-by: Raphael Gallais-Pou Reviewed-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20240226152135.8671-1-rgallaispou@gmail.com Signed-off-by: Greg Kroah-Hartman --- .../devicetree/bindings/serial/st,asc.yaml | 55 ++++++++++++++++++++++ .../devicetree/bindings/serial/st-asc.txt | 18 ------- 2 files changed, 55 insertions(+), 18 deletions(-) create mode 100644 Documentation/devicetree/bindings/serial/st,asc.yaml delete mode 100644 Documentation/devicetree/bindings/serial/st-asc.txt (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/serial/st,asc.yaml b/Documentation/devicetree/bindings/serial/st,asc.yaml new file mode 100644 index 000000000000..f2083388f36b --- /dev/null +++ b/Documentation/devicetree/bindings/serial/st,asc.yaml @@ -0,0 +1,55 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/serial/st,asc.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: STMicroelectronics STi SoCs Serial Port + +maintainers: + - Patrice Chotard + +allOf: + - $ref: serial.yaml# + +properties: + compatible: + const: st,asc + + reg: + maxItems: 1 + + interrupts: + maxItems: 1 + + clocks: + maxItems: 1 + + st,hw-flow-ctrl: + description: When set, enable hardware flow control. + type: boolean + + st,force-m1: + description: When set, force asc to be in Mode-1. This is recommended for + high bit rates above 19.2K. + type: boolean + +required: + - compatible + - reg + - interrupts + - clocks + +unevaluatedProperties: false + +examples: + - | + #include + #include + serial@9830000 { + compatible = "st,asc"; + reg = <0x9830000 0x2c>; + interrupts = ; + clocks = <&clk_s_c0_flexgen CLK_EXT2F_A9>; + }; +... diff --git a/Documentation/devicetree/bindings/serial/st-asc.txt b/Documentation/devicetree/bindings/serial/st-asc.txt deleted file mode 100644 index a1b9b6f3490a..000000000000 --- a/Documentation/devicetree/bindings/serial/st-asc.txt +++ /dev/null @@ -1,18 +0,0 @@ -*st-asc(Serial Port) - -Required properties: -- compatible : Should be "st,asc". -- reg, reg-names, interrupts, interrupt-names : Standard way to define device - resources with names. look in - Documentation/devicetree/bindings/resource-names.txt - -Optional properties: -- st,hw-flow-ctrl bool flag to enable hardware flow control. -- st,force-m1 bool flat to force asc to be in Mode-1 recommended - for high bit rates (above 19.2K) -Example: -serial@fe440000{ - compatible = "st,asc"; - reg = <0xfe440000 0x2c>; - interrupts = <0 209 0>; -}; -- cgit v1.2.3-70-g09d2 From d6c0d892b44cd16e0421909cf7f2883b9e625e4a Mon Sep 17 00:00:00 2001 From: Valentin Caron Date: Thu, 18 Jan 2024 10:11:35 +0100 Subject: dt-bindings: serial: stm32: add power-domains property STM32 serial may be in a power domain. Allow a single 'power-domains' entry for STM32 serial devices. Signed-off-by: Valentin Caron Acked-by: Conor Dooley Link: https://lore.kernel.org/r/20240118091135.3314330-1-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman --- Documentation/devicetree/bindings/serial/st,stm32-uart.yaml | 3 +++ 1 file changed, 3 insertions(+) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml b/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml index 1df8ffe95fc6..62f97da1b2fd 100644 --- a/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml +++ b/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml @@ -58,6 +58,9 @@ properties: wakeup-source: true + power-domains: + maxItems: 1 + rx-threshold: description: If value is set to 1, RX FIFO threshold is disabled. -- cgit v1.2.3-70-g09d2