diff options
| -rw-r--r-- | Documentation/devicetree/bindings/serial/litex,liteuart.yaml | 38 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/soc/litex/litex,soc-controller.yaml | 39 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 | ||||
| -rw-r--r-- | MAINTAINERS | 10 | ||||
| -rw-r--r-- | arch/openrisc/boot/dts/or1klitex.dts | 55 | ||||
| -rw-r--r-- | arch/openrisc/configs/or1klitex_defconfig | 18 | ||||
| -rw-r--r-- | arch/openrisc/include/asm/Kbuild | 1 | ||||
| -rw-r--r-- | arch/openrisc/kernel/traps.c | 4 | ||||
| -rw-r--r-- | drivers/soc/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/soc/Makefile | 1 | ||||
| -rw-r--r-- | drivers/soc/litex/Kconfig | 19 | ||||
| -rw-r--r-- | drivers/soc/litex/Makefile | 3 | ||||
| -rw-r--r-- | drivers/soc/litex/litex_soc_ctrl.c | 176 | ||||
| -rw-r--r-- | drivers/tty/serial/Kconfig | 32 | ||||
| -rw-r--r-- | drivers/tty/serial/Makefile | 1 | ||||
| -rw-r--r-- | drivers/tty/serial/liteuart.c | 404 | ||||
| -rw-r--r-- | include/linux/litex.h | 102 |
17 files changed, 903 insertions, 3 deletions
diff --git a/Documentation/devicetree/bindings/serial/litex,liteuart.yaml b/Documentation/devicetree/bindings/serial/litex,liteuart.yaml new file mode 100644 index 000000000000..bc79b3cca542 --- /dev/null +++ b/Documentation/devicetree/bindings/serial/litex,liteuart.yaml @@ -0,0 +1,38 @@ +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause + +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/serial/litex,liteuart.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: LiteUART serial controller + +maintainers: + - Karol Gugala <kgugala@antmicro.com> + - Mateusz Holenko <mholenko@antmicro.com> + +description: | + LiteUART serial controller is a part of the LiteX FPGA SoC builder. It supports + multiple CPU architectures, currently including e.g. OpenRISC and RISC-V. + +properties: + compatible: + const: litex,liteuart + + reg: + maxItems: 1 + + interrupts: + maxItems: 1 + +required: + - compatible + - reg + +examples: + - | + uart0: serial@e0001800 { + compatible = "litex,liteuart"; + reg = <0xe0001800 0x100>; + interrupts = <2>; + }; diff --git a/Documentation/devicetree/bindings/soc/litex/litex,soc-controller.yaml b/Documentation/devicetree/bindings/soc/litex/litex,soc-controller.yaml new file mode 100644 index 000000000000..e2b788796e79 --- /dev/null +++ b/Documentation/devicetree/bindings/soc/litex/litex,soc-controller.yaml @@ -0,0 +1,39 @@ +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause +# Copyright 2020 Antmicro <www.antmicro.com> +%YAML 1.2 +--- +$id: "http://devicetree.org/schemas/soc/litex/litex,soc-controller.yaml#" +$schema: "http://devicetree.org/meta-schemas/core.yaml#" + +title: LiteX SoC Controller driver + +description: | + This is the SoC Controller driver for the LiteX SoC Builder. + Its purpose is to verify LiteX CSR (Control&Status Register) access + operations and provide functions for other drivers to read/write CSRs + and to check if those accessors are ready to be used. + +maintainers: + - Karol Gugala <kgugala@antmicro.com> + - Mateusz Holenko <mholenko@antmicro.com> + +properties: + compatible: + const: litex,soc-controller + + reg: + maxItems: 1 + +required: + - compatible + - reg + +examples: + - | + soc_ctrl0: soc-controller@f0000000 { + compatible = "litex,soc-controller"; + reg = <0xf0000000 0xc>; + status = "okay"; + }; + +... diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml index 49e888a1467e..ffaf833b97ee 100644 --- a/Documentation/devicetree/bindings/vendor-prefixes.yaml +++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml @@ -621,6 +621,8 @@ patternProperties: description: Linux-specific binding "^linx,.*": description: Linx Technologies + "^litex,.*": + description: LiteX SoC builder "^lltc,.*": description: Linear Technology Corporation "^logicpd,.*": diff --git a/MAINTAINERS b/MAINTAINERS index c52fedb1a8e8..28d7acdb0591 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10264,6 +10264,16 @@ L: kunit-dev@googlegroups.com S: Maintained F: lib/list-test.c +LITEX PLATFORM +M: Karol Gugala <kgugala@antmicro.com> +M: Mateusz Holenko <mholenko@antmicro.com> +S: Maintained +F: Documentation/devicetree/bindings/*/litex,*.yaml +F: arch/openrisc/boot/dts/or1klitex.dts +F: drivers/soc/litex/litex_soc_ctrl.c +F: drivers/tty/serial/liteuart.c +F: include/linux/litex.h + LIVE PATCHING M: Josh Poimboeuf <jpoimboe@redhat.com> M: Jiri Kosina <jikos@kernel.org> diff --git a/arch/openrisc/boot/dts/or1klitex.dts b/arch/openrisc/boot/dts/or1klitex.dts new file mode 100644 index 000000000000..3f9867aa3844 --- /dev/null +++ b/arch/openrisc/boot/dts/or1klitex.dts @@ -0,0 +1,55 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * LiteX-based System on Chip + * + * Copyright (C) 2019 Antmicro <www.antmicro.com> + */ + +/dts-v1/; +/ { + compatible = "opencores,or1ksim"; + #address-cells = <1>; + #size-cells = <1>; + interrupt-parent = <&pic>; + + aliases { + serial0 = &serial0; + }; + + chosen { + bootargs = "console=liteuart"; + }; + + memory@0 { + device_type = "memory"; + reg = <0x00000000 0x10000000>; + }; + + cpus { + #address-cells = <1>; + #size-cells = <0>; + cpu@0 { + compatible = "opencores,or1200-rtlsvn481"; + reg = <0>; + clock-frequency = <100000000>; + }; + }; + + pic: pic { + compatible = "opencores,or1k-pic"; + #interrupt-cells = <1>; + interrupt-controller; + }; + + serial0: serial@e0002000 { + device_type = "serial"; + compatible = "litex,liteuart"; + reg = <0xe0002000 0x100>; + }; + + soc_ctrl0: soc_controller@e0000000 { + compatible = "litex,soc-controller"; + reg = <0xe0000000 0xc>; + status = "okay"; + }; +}; diff --git a/arch/openrisc/configs/or1klitex_defconfig b/arch/openrisc/configs/or1klitex_defconfig new file mode 100644 index 000000000000..3c2c70d3d740 --- /dev/null +++ b/arch/openrisc/configs/or1klitex_defconfig @@ -0,0 +1,18 @@ +CONFIG_BLK_DEV_INITRD=y +CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y +CONFIG_BUG_ON_DATA_CORRUPTION=y +CONFIG_CC_OPTIMIZE_FOR_SIZE=y +CONFIG_DEVTMPFS=y +CONFIG_DEVTMPFS_MOUNT=y +CONFIG_EMBEDDED=y +CONFIG_HZ_100=y +CONFIG_INITRAMFS_SOURCE="openrisc-rootfs.cpio.gz" +CONFIG_OF_OVERLAY=y +CONFIG_OPENRISC_BUILTIN_DTB="or1klitex" +CONFIG_PANIC_ON_OOPS=y +CONFIG_PRINTK_TIME=y +CONFIG_LITEX_SOC_CONTROLLER=y +CONFIG_SERIAL_LITEUART=y +CONFIG_SERIAL_LITEUART_CONSOLE=y +CONFIG_SOFTLOCKUP_DETECTOR=y +CONFIG_TTY_PRINTK=y diff --git a/arch/openrisc/include/asm/Kbuild b/arch/openrisc/include/asm/Kbuild index ca5987e11053..442f3d3bcd90 100644 --- a/arch/openrisc/include/asm/Kbuild +++ b/arch/openrisc/include/asm/Kbuild @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 generic-y += extable.h generic-y += kvm_para.h +generic-y += local64.h generic-y += mcs_spinlock.h generic-y += qspinlock_types.h generic-y += qspinlock.h diff --git a/arch/openrisc/kernel/traps.c b/arch/openrisc/kernel/traps.c index 206e5325e61b..4d61333c2623 100644 --- a/arch/openrisc/kernel/traps.c +++ b/arch/openrisc/kernel/traps.c @@ -238,9 +238,7 @@ void __init trap_init(void) asmlinkage void do_trap(struct pt_regs *regs, unsigned long address) { - force_sig_fault(SIGTRAP, TRAP_TRACE, (void __user *)address); - - regs->pc += 4; + force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc); } asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address) diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig index 425ab6f7e375..d097d070f579 100644 --- a/drivers/soc/Kconfig +++ b/drivers/soc/Kconfig @@ -9,6 +9,7 @@ source "drivers/soc/bcm/Kconfig" source "drivers/soc/fsl/Kconfig" source "drivers/soc/imx/Kconfig" source "drivers/soc/ixp4xx/Kconfig" +source "drivers/soc/litex/Kconfig" source "drivers/soc/mediatek/Kconfig" source "drivers/soc/qcom/Kconfig" source "drivers/soc/renesas/Kconfig" diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile index 8fa43a2d17e7..699b758d28e4 100644 --- a/drivers/soc/Makefile +++ b/drivers/soc/Makefile @@ -14,6 +14,7 @@ obj-$(CONFIG_ARCH_GEMINI) += gemini/ obj-y += imx/ obj-$(CONFIG_ARCH_IXP4XX) += ixp4xx/ obj-$(CONFIG_SOC_XWAY) += lantiq/ +obj-$(CONFIG_LITEX_SOC_CONTROLLER) += litex/ obj-y += mediatek/ obj-y += amlogic/ obj-y += qcom/ diff --git a/drivers/soc/litex/Kconfig b/drivers/soc/litex/Kconfig new file mode 100644 index 000000000000..7c6b009b6f6c --- /dev/null +++ b/drivers/soc/litex/Kconfig @@ -0,0 +1,19 @@ +# SPDX-License_Identifier: GPL-2.0 + +menu "Enable LiteX SoC Builder specific drivers" + +config LITEX + bool + +config LITEX_SOC_CONTROLLER + tristate "Enable LiteX SoC Controller driver" + depends on OF || COMPILE_TEST + select LITEX + help + This option enables the SoC Controller Driver which verifies + LiteX CSR access and provides common litex_get_reg/litex_set_reg + accessors. + All drivers that use functions from litex.h must depend on + LITEX. + +endmenu diff --git a/drivers/soc/litex/Makefile b/drivers/soc/litex/Makefile new file mode 100644 index 000000000000..98ff7325b1c0 --- /dev/null +++ b/drivers/soc/litex/Makefile @@ -0,0 +1,3 @@ +# SPDX-License_Identifier: GPL-2.0 + +obj-$(CONFIG_LITEX_SOC_CONTROLLER) += litex_soc_ctrl.o diff --git a/drivers/soc/litex/litex_soc_ctrl.c b/drivers/soc/litex/litex_soc_ctrl.c new file mode 100644 index 000000000000..1217cafdfd4d --- /dev/null +++ b/drivers/soc/litex/litex_soc_ctrl.c @@ -0,0 +1,176 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * LiteX SoC Controller Driver + * + * Copyright (C) 2020 Antmicro <www.antmicro.com> + * + */ + +#include <linux/litex.h> +#include <linux/device.h> +#include <linux/errno.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/printk.h> +#include <linux/module.h> +#include <linux/errno.h> +#include <linux/io.h> + +/* + * LiteX SoC Generator, depending on the configuration, can split a single + * logical CSR (Control&Status Register) into a series of consecutive physical + * registers. + * + * For example, in the configuration with 8-bit CSR Bus, 32-bit aligned (the + * default one for 32-bit CPUs) a 32-bit logical CSR will be generated as four + * 32-bit physical registers, each one containing one byte of meaningful data. + * + * For details see: https://github.com/enjoy-digital/litex/wiki/CSR-Bus + * + * The purpose of `litex_set_reg`/`litex_get_reg` is to implement the logic + * of writing to/reading from the LiteX CSR in a single place that can be + * then reused by all LiteX drivers. + */ + +/** + * litex_set_reg() - Writes the value to the LiteX CSR (Control&Status Register) + * @reg: Address of the CSR + * @reg_size: The width of the CSR expressed in the number of bytes + * @val: Value to be written to the CSR + * + * In the currently supported LiteX configuration (8-bit CSR Bus, 32-bit aligned), + * a 32-bit LiteX CSR is generated as 4 consecutive 32-bit physical registers, + * each one containing one byte of meaningful data. + * + * This function splits a single possibly multi-byte write into a series of + * single-byte writes with a proper offset. + */ +void litex_set_reg(void __iomem *reg, unsigned long reg_size, + unsigned long val) +{ + unsigned long shifted_data, shift, i; + + for (i = 0; i < reg_size; ++i) { + shift = ((reg_size - i - 1) * LITEX_SUBREG_SIZE_BIT); + shifted_data = val >> shift; + + WRITE_LITEX_SUBREGISTER(shifted_data, reg, i); + } +} +EXPORT_SYMBOL_GPL(litex_set_reg); + +/** + * litex_get_reg() - Reads the value of the LiteX CSR (Control&Status Register) + * @reg: Address of the CSR + * @reg_size: The width of the CSR expressed in the number of bytes + * + * Return: Value read from the CSR + * + * In the currently supported LiteX configuration (8-bit CSR Bus, 32-bit aligned), + * a 32-bit LiteX CSR is generated as 4 consecutive 32-bit physical registers, + * each one containing one byte of meaningful data. + * + * This function generates a series of single-byte reads with a proper offset + * and joins their results into a single multi-byte value. + */ +unsigned long litex_get_reg(void __iomem *reg, unsigned long reg_size) +{ + unsigned long shifted_data, shift, i; + unsigned long result = 0; + + for (i = 0; i < reg_size; ++i) { + shifted_data = READ_LITEX_SUBREGISTER(reg, i); + + shift = ((reg_size - i - 1) * LITEX_SUBREG_SIZE_BIT); + result |= (shifted_data << shift); + } + + return result; +} +EXPORT_SYMBOL_GPL(litex_get_reg); + +#define SCRATCH_REG_OFF 0x04 +#define SCRATCH_REG_VALUE 0x12345678 +#define SCRATCH_TEST_VALUE 0xdeadbeef + +/* + * Check LiteX CSR read/write access + * + * This function reads and writes a scratch register in order to verify if CSR + * access works. + * + * In case any problems are detected, the driver should panic. + * + * Access to the LiteX CSR is, by design, done in CPU native endianness. + * The driver should not dynamically configure access functions when + * the endianness mismatch is detected. Such situation indicates problems in + * the soft SoC design and should be solved at the LiteX generator level, + * not in the software. + */ +static int litex_check_csr_access(void __iomem *reg_addr) +{ + unsigned long reg; + + reg = litex_read32(reg_addr + SCRATCH_REG_OFF); + + if (reg != SCRATCH_REG_VALUE) { + panic("Scratch register read error - the system is probably broken! Expected: 0x%x but got: 0x%lx", + SCRATCH_REG_VALUE, reg); + return -EINVAL; + } + + litex_write32(reg_addr + SCRATCH_REG_OFF, SCRATCH_TEST_VALUE); + reg = litex_read32(reg_addr + SCRATCH_REG_OFF); + + if (reg != SCRATCH_TEST_VALUE) { + panic("Scratch register write error - the system is probably broken! Expected: 0x%x but got: 0x%lx", + SCRATCH_TEST_VALUE, reg); + return -EINVAL; + } + + /* restore original value of the SCRATCH register */ + litex_write32(reg_addr + SCRATCH_REG_OFF, SCRATCH_REG_VALUE); + + pr_info("LiteX SoC Controller driver initialized"); + + return 0; +} + +struct litex_soc_ctrl_device { + void __iomem *base; +}; + +static const struct of_device_id litex_soc_ctrl_of_match[] = { + {.compatible = "litex,soc-controller"}, + {}, +}; + +MODULE_DEVICE_TABLE(of, litex_soc_ctrl_of_match); + +static int litex_soc_ctrl_probe(struct platform_device *pdev) +{ + struct litex_soc_ctrl_device *soc_ctrl_dev; + + soc_ctrl_dev = devm_kzalloc(&pdev->dev, sizeof(*soc_ctrl_dev), GFP_KERNEL); + if (!soc_ctrl_dev) + return -ENOMEM; + + soc_ctrl_dev->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(soc_ctrl_dev->base)) + return PTR_ERR(soc_ctrl_dev->base); + + return litex_check_csr_access(soc_ctrl_dev->base); +} + +static struct platform_driver litex_soc_ctrl_driver = { + .driver = { + .name = "litex-soc-controller", + .of_match_table = of_match_ptr(litex_soc_ctrl_of_match) + }, + .probe = litex_soc_ctrl_probe, +}; + +module_platform_driver(litex_soc_ctrl_driver); +MODULE_DESCRIPTION("LiteX SoC Controller driver"); +MODULE_AUTHOR("Antmicro <www.antmicro.com>"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index 12d71d5eb6ca..34a2899e69c0 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -1567,6 +1567,38 @@ config SERIAL_MILBEAUT_USIO_CONSOLE receives all kernel messages and warnings and which allows logins in single user mode). +config SERIAL_LITEUART + tristate "LiteUART serial port support" + depends on HAS_IOMEM + depends on OF || COMPILE_TEST + depends on LITEX + select SERIAL_CORE + help + This driver is for the FPGA-based LiteUART serial controller from LiteX + SoC builder. + + Say 'Y' or 'M' here if you wish to use the LiteUART serial controller. + Otherwise, say 'N'. + +config SERIAL_LITEUART_MAX_PORTS + int "Maximum number of LiteUART ports" + depends on SERIAL_LITEUART + default "1" + help + Set this to the maximum number of serial ports you want the driver + to support. + +config SERIAL_LITEUART_CONSOLE + bool "LiteUART serial port console support" + depends on SERIAL_LITEUART=y + select SERIAL_CORE_CONSOLE + help + Say 'Y' or 'M' here if you wish to use the FPGA-based LiteUART serial + controller from LiteX SoC builder as the system console + (the system console is the device which receives all kernel messages + and warnings and which allows logins in single user mode). + Otherwise, say 'N'. + endmenu config SERIAL_MCTRL_GPIO diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile index af44b231123c..b85d53f9e9ff 100644 --- a/drivers/tty/serial/Makefile +++ b/drivers/tty/serial/Makefile @@ -89,6 +89,7 @@ obj-$(CONFIG_SERIAL_OWL) += owl-uart.o obj-$(CONFIG_SERIAL_RDA) += rda-uart.o obj-$(CONFIG_SERIAL_MILBEAUT_USIO) += milbeaut_usio.o obj-$(CONFIG_SERIAL_SIFIVE) += sifive.o +obj-$(CONFIG_SERIAL_LITEUART) += liteuart.o # GPIOLIB helpers for modem control lines obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o diff --git a/drivers/tty/serial/liteuart.c b/drivers/tty/serial/liteuart.c new file mode 100644 index 000000000000..64842f3539e1 --- /dev/null +++ b/drivers/tty/serial/liteuart.c @@ -0,0 +1,404 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * LiteUART serial controller (LiteX) Driver + * + * Copyright (C) 2019-2020 Antmicro <www.antmicro.com> + */ + +#include <linux/console.h> +#include <linux/litex.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_platform.h> +#include <linux/serial.h> +#include <linux/serial_core.h> +#include <linux/slab.h> +#include <linux/timer.h> +#include <linux/tty_flip.h> +#include <linux/xarray.h> + +/* + * CSRs definitions (base address offsets + width) + * + * The definitions below are true for LiteX SoC configured for 8-bit CSR Bus, + * 32-bit aligned. + * + * Supporting other configurations might require new definitions or a more + * generic way of indexing the LiteX CSRs. + * + * For more details on how CSRs are defined and handled in LiteX, see comments + * in the LiteX SoC Driver: drivers/soc/litex/litex_soc_ctrl.c + */ +#define OFF_RXTX 0x00 +#define OFF_TXFULL 0x04 +#define OFF_RXEMPTY 0x08 +#define OFF_EV_STATUS 0x0c +#define OFF_EV_PENDING 0x10 +#define OFF_EV_ENABLE 0x14 + +/* events */ +#define EV_TX 0x1 +#define EV_RX 0x2 + +struct liteuart_port { + struct uart_port port; + struct timer_list timer; + u32 id; +}; + +#define to_liteuart_port(port) container_of(port, struct liteuart_port, port) + +static DEFINE_XARRAY_FLAGS(liteuart_array, XA_FLAGS_ALLOC); + +#ifdef CONFIG_SERIAL_LITEUART_CONSOLE +static struct console liteuart_console; +#endif + +static struct uart_driver liteuart_driver = { + .owner = THIS_MODULE, + .driver_name = "liteuart", + .dev_name = "ttyLXU", + .major = 0, + .minor = 0, + .nr = CONFIG_SERIAL_LITEUART_MAX_PORTS, +#ifdef CONFIG_SERIAL_LITEUART_CONSOLE + .cons = &liteuart_console, +#endif +}; + +static void liteuart_timer(struct timer_list *t) +{ + struct liteuart_port *uart = from_timer(uart, t, timer); + struct uart_port *port = &uart->port; + unsigned char __iomem *membase = port->membase; + unsigned int flg = TTY_NORMAL; + int ch; + unsigned long status; + + while ((status = !litex_read8(membase + OFF_RXEMPTY)) == 1) { + ch = litex_read8(membase + OFF_RXTX); + port->icount.rx++; + + /* necessary for RXEMPTY to refresh its value */ + litex_write8(membase + OFF_EV_PENDING, EV_TX | EV_RX); + + /* no overflow bits in status */ + if (!(uart_handle_sysrq_char(port, ch))) + uart_insert_char(port, status, 0, ch, flg); + + tty_flip_buffer_push(&port->state->port); + } + + mod_timer(&uart->timer, jiffies + uart_poll_timeout(port)); +} + +static void liteuart_putchar(struct uart_port *port, int ch) +{ + while (litex_read8(port->membase + OFF_TXFULL)) + cpu_relax(); + + litex_write8(port->membase + OFF_RXTX, ch); +} + +static unsigned int liteuart_tx_empty(struct uart_port *port) +{ + /* not really tx empty, just checking if tx is not full */ + if (!litex_read8(port->membase + OFF_TXFULL)) + return TIOCSER_TEMT; + + return 0; +} + +static void liteuart_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + /* modem control register is not present in LiteUART */ +} + +static unsigned int liteuart_get_mctrl(struct uart_port *port) +{ + return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR; +} + +static void liteuart_stop_tx(struct uart_port *port) +{ +} + +static void liteuart_start_tx(struct uart_port *port) +{ + struct circ_buf *xmit = &port->state->xmit; + unsigned char ch; + + if (unlikely(port->x_char)) { + litex_write8(port->membase + OFF_RXTX, port->x_char); + port->icount.tx++; + port->x_char = 0; + } else if (!uart_circ_empty(xmit)) { + while (xmit->head != xmit->tail) { + ch = xmit->buf[xmit->tail]; + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + port->icount.tx++; + liteuart_putchar(port, ch); + } + } + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); +} + +static void liteuart_stop_rx(struct uart_port *port) +{ + struct liteuart_port *uart = to_liteuart_port(port); + + /* just delete timer */ + del_timer(&uart->timer); +} + +static void liteuart_break_ctl(struct uart_port *port, int break_state) +{ + /* LiteUART doesn't support sending break signal */ +} + +static int liteuart_startup(struct uart_port *port) +{ + struct liteuart_port *uart = to_liteuart_port(port); + + /* disable events */ + litex_write8(port->membase + OFF_EV_ENABLE, 0); + + /* prepare timer for polling */ + timer_setup(&uart->timer, liteuart_timer, 0); + mod_timer(&uart->timer, jiffies + uart_poll_timeout(port)); + + return 0; +} + +static void liteuart_shutdown(struct uart_port *port) +{ +} + +static void liteuart_set_termios(struct uart_port *port, struct ktermios *new, + struct ktermios *old) +{ + unsigned int baud; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + + /* update baudrate */ + baud = uart_get_baud_rate(port, new, old, 0, 460800); + uart_update_timeout(port, new->c_cflag, baud); + + spin_unlock_irqrestore(&port->lock, flags); +} + +static const char *liteuart_type(struct uart_port *port) +{ + return "liteuart"; +} + +static void liteuart_release_port(struct uart_port *port) +{ +} + +static int liteuart_request_port(struct uart_port *port) +{ + return 0; +} + +static void liteuart_config_port(struct uart_port *port, int flags) +{ + /* + * Driver core for serial ports forces a non-zero value for port type. + * Write an arbitrary value here to accommodate the serial core driver, + * as ID part of UAPI is redundant. + */ + port->type = 1; +} + +static int liteuart_verify_port(struct uart_port *port, + struct serial_struct *ser) +{ + if (port->type != PORT_UNKNOWN && ser->type != 1) + return -EINVAL; + + return 0; +} + +static const struct uart_ops liteuart_ops = { + .tx_empty = liteuart_tx_empty, + .set_mctrl = liteuart_set_mctrl, + .get_mctrl = liteuart_get_mctrl, + .stop_tx = liteuart_stop_tx, + .start_tx = liteuart_start_tx, + .stop_rx = liteuart_stop_rx, + .break_ctl = liteuart_break_ctl, + .startup = liteuart_startup, + .shutdown = liteuart_shutdown, + .set_termios = liteuart_set_termios, + .type = liteuart_type, + .release_port = liteuart_release_port, + .request_port = liteuart_request_port, + .config_port = liteuart_config_port, + .verify_port = liteuart_verify_port, +}; + +static int liteuart_probe(struct platform_device *pdev) +{ + struct liteuart_port *uart; + struct uart_port *port; + struct xa_limit limit; + int dev_id, ret; + + /* look for aliases; auto-enumerate for free index if not found */ + dev_id = of_alias_get_id(pdev->dev.of_node, "serial"); + if (dev_id < 0) + limit = XA_LIMIT(0, CONFIG_SERIAL_LITEUART_MAX_PORTS); + else + limit = XA_LIMIT(dev_id, dev_id); + + uart = devm_kzalloc(&pdev->dev, sizeof(struct liteuart_port), GFP_KERNEL); + if (!uart) + return -ENOMEM; + + ret = xa_alloc(&liteuart_array, &dev_id, uart, limit, GFP_KERNEL); + if (ret) + return ret; + + uart->id = dev_id; + port = &uart->port; + + /* get membase */ + port->membase = devm_platform_get_and_ioremap_resource(pdev, 0, NULL); + if (!port->membase) + return -ENXIO; + + /* values not from device tree */ + port->dev = &pdev->dev; + port->iotype = UPIO_MEM; + port->flags = UPF_BOOT_AUTOCONF; + port->ops = &liteuart_ops; + port->regshift = 2; + port->fifosize = 16; + port->iobase = 1; + port->type = PORT_UNKNOWN; + port->line = dev_id; + spin_lock_init(&port->lock); + + return uart_add_one_port(&liteuart_driver, &uart->port); +} + +static int liteuart_remove(struct platform_device *pdev) +{ + struct uart_port *port = platform_get_drvdata(pdev); + struct liteuart_port *uart = to_liteuart_port(port); + + xa_erase(&liteuart_array, uart->id); + + return 0; +} + +static const struct of_device_id liteuart_of_match[] = { + { .compatible = "litex,liteuart" }, + {} +}; +MODULE_DEVICE_TABLE(of, liteuart_of_match); + +static struct platform_driver liteuart_platform_driver = { + .probe = liteuart_probe, + .remove = liteuart_remove, + .driver = { + .name = "liteuart", + .of_match_table = liteuart_of_match, + }, +}; + +#ifdef CONFIG_SERIAL_LITEUART_CONSOLE + +static void liteuart_console_write(struct console *co, const char *s, + unsigned int count) +{ + struct liteuart_port *uart; + struct uart_port *port; + unsigned long flags; + + uart = (struct liteuart_port *)xa_load(&liteuart_array, co->index); + port = &uart->port; + + spin_lock_irqsave(&port->lock, flags); + uart_console_write(port, s, count, liteuart_putchar); + spin_unlock_irqrestore(&port->lock, flags); +} + +static int liteuart_console_setup(struct console *co, char *options) +{ + struct liteuart_port *uart; + struct uart_port *port; + int baud = 115200; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + + uart = (struct liteuart_port *)xa_load(&liteuart_array, co->index); + if (!uart) + return -ENODEV; + + port = &uart->port; + if (!port->membase) + return -ENODEV; + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + + return uart_set_options(port, co, baud, parity, bits, flow); +} + +static struct console liteuart_console = { + .name = "liteuart", + .write = liteuart_console_write, + .device = uart_console_device, + .setup = liteuart_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &liteuart_driver, +}; + +static int __init liteuart_console_init(void) +{ + register_console(&liteuart_console); + + return 0; +} +console_initcall(liteuart_console_init); +#endif /* CONFIG_SERIAL_LITEUART_CONSOLE */ + +static int __init liteuart_init(void) +{ + int res; + + res = uart_register_driver(&liteuart_driver); + if (res) + return res; + + res = platform_driver_register(&liteuart_platform_driver); + if (res) { + uart_unregister_driver(&liteuart_driver); + return res; + } + + return 0; +} + +static void __exit liteuart_exit(void) +{ + platform_driver_unregister(&liteuart_platform_driver); + uart_unregister_driver(&liteuart_driver); +} + +module_init(liteuart_init); +module_exit(liteuart_exit); + +MODULE_AUTHOR("Antmicro <www.antmicro.com>"); +MODULE_DESCRIPTION("LiteUART serial driver"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform: liteuart"); diff --git a/include/linux/litex.h b/include/linux/litex.h new file mode 100644 index 000000000000..40f5be503593 --- /dev/null +++ b/include/linux/litex.h @@ -0,0 +1,102 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Common LiteX header providing + * helper functions for accessing CSRs. + * + * Implementation of the functions is provided by + * the LiteX SoC Controller driver. + * + * Copyright (C) 2019-2020 Antmicro <www.antmicro.com> + */ + +#ifndef _LINUX_LITEX_H +#define _LINUX_LITEX_H + +#include <linux/io.h> +#include <linux/types.h> +#include <linux/compiler_types.h> + +/* + * The parameters below are true for LiteX SoCs configured for 8-bit CSR Bus, + * 32-bit aligned. + * + * Supporting other configurations will require extending the logic in this + * header and in the LiteX SoC controller driver. + */ +#define LITEX_REG_SIZE 0x4 +#define LITEX_SUBREG_SIZE 0x1 +#define LITEX_SUBREG_SIZE_BIT (LITEX_SUBREG_SIZE * 8) + +#define WRITE_LITEX_SUBREGISTER(val, base_offset, subreg_id) \ + writel((u32 __force)cpu_to_le32(val), base_offset + (LITEX_REG_SIZE * subreg_id)) + +#define READ_LITEX_SUBREGISTER(base_offset, subreg_id) \ + le32_to_cpu((__le32 __force)readl(base_offset + (LITEX_REG_SIZE * subreg_id))) + +void litex_set_reg(void __iomem *reg, unsigned long reg_sz, unsigned long val); + +unsigned long litex_get_reg(void __iomem *reg, unsigned long reg_sz); + +static inline void litex_write8(void __iomem *reg, u8 val) +{ + WRITE_LITEX_SUBREGISTER(val, reg, 0); +} + +static inline void litex_write16(void __iomem *reg, u16 val) +{ + WRITE_LITEX_SUBREGISTER(val >> 8, reg, 0); + WRITE_LITEX_SUBREGISTER(val, reg, 1); +} + +static inline void litex_write32(void __iomem *reg, u32 val) +{ + WRITE_LITEX_SUBREGISTER(val >> 24, reg, 0); + WRITE_LITEX_SUBREGISTER(val >> 16, reg, 1); + WRITE_LITEX_SUBREGISTER(val >> 8, reg, 2); + WRITE_LITEX_SUBREGISTER(val, reg, 3); +} + +static inline void litex_write64(void __iomem *reg, u64 val) +{ + WRITE_LITEX_SUBREGISTER(val >> 56, reg, 0); + WRITE_LITEX_SUBREGISTER(val >> 48, reg, 1); + WRITE_LITEX_SUBREGISTER(val >> 40, reg, 2); + WRITE_LITEX_SUBREGISTER(val >> 32, reg, 3); + WRITE_LITEX_SUBREGISTER(val >> 24, reg, 4); + WRITE_LITEX_SUBREGISTER(val >> 16, reg, 5); + WRITE_LITEX_SUBREGISTER(val >> 8, reg, 6); + WRITE_LITEX_SUBREGISTER(val, reg, 7); +} + +static inline u8 litex_read8(void __iomem *reg) +{ + return READ_LITEX_SUBREGISTER(reg, 0); +} + +static inline u16 litex_read16(void __iomem *reg) +{ + return (READ_LITEX_SUBREGISTER(reg, 0) << 8) + | (READ_LITEX_SUBREGISTER(reg, 1)); +} + +static inline u32 litex_read32(void __iomem *reg) +{ + return (READ_LITEX_SUBREGISTER(reg, 0) << 24) + | (READ_LITEX_SUBREGISTER(reg, 1) << 16) + | (READ_LITEX_SUBREGISTER(reg, 2) << 8) + | (READ_LITEX_SUBREGISTER(reg, 3)); +} + +static inline u64 litex_read64(void __iomem *reg) +{ + return ((u64)READ_LITEX_SUBREGISTER(reg, 0) << 56) + | ((u64)READ_LITEX_SUBREGISTER(reg, 1) << 48) + | ((u64)READ_LITEX_SUBREGISTER(reg, 2) << 40) + | ((u64)READ_LITEX_SUBREGISTER(reg, 3) << 32) + | ((u64)READ_LITEX_SUBREGISTER(reg, 4) << 24) + | ((u64)READ_LITEX_SUBREGISTER(reg, 5) << 16) + | ((u64)READ_LITEX_SUBREGISTER(reg, 6) << 8) + | ((u64)READ_LITEX_SUBREGISTER(reg, 7)); +} + +#endif /* _LINUX_LITEX_H */ |