From patchwork Sun Nov 20 08:21:09 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jisheng Zhang X-Patchwork-Id: 13049924 X-Patchwork-Delegate: mail@conchuod.ie Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A5B5AC4332F for ; Sun, 20 Nov 2022 08:31:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=u0d3GFuGErc0uIUjoAR0rPXGtaHGWi5Izg5DOI5aQtk=; b=Wobjm0UF4z565e ZvtDI7eV8atwzO3h6ARkGqJAvAyTQ0B7jRtpgKXcx2xr5yuthJOPJyC5DT0I6dv9vxNztrFI4ONYU +F6F2fxB2fslN5+7FeC6IH4nECXZsTnVHRJa0Ghvf5t/LeUTubdPnW1A8IqvbeKR9demfIh6bIiF8 cZkzzeqcOz2sil7z5nZgkvGb347bBxWVoo9aanXdy9o1Px1RKsrybJ7xAN9oeM/x85USwdVJEE3l7 TGin4wIAVtnB5zhqNXjRDTEgxRQgjcpXW23AjjIO/hQgDx7NHAf45NrMBrlcTT2ty1y0vd2tzaNvB eQxToOPSvmmyEEXZLRVQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1owfjc-0031Jp-Ef; Sun, 20 Nov 2022 08:31:28 +0000 Received: from ams.source.kernel.org ([145.40.68.75]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1owfjT-0031CM-CE for linux-riscv@lists.infradead.org; Sun, 20 Nov 2022 08:31:22 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 87A4BB8094E; Sun, 20 Nov 2022 08:31:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ACFA9C433C1; Sun, 20 Nov 2022 08:31:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1668933070; bh=ZpJe4VmlTSsTmZ7SldQF5itUf4+Wj5uLENRTgWLQHeU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=T2K/cRNL3qu9mjHNlQiu6aDCpC8ASzfHaPxH6CeFuTKK88griMvCZHvkaVC9XoENU aU6pBvjS3j67NyNra1ZIaKc8Vc2IXaI/p3J6gRDI3SbJooZgiwdG31OUJfn6b61P8v e8GbYtN+sY7hzYI7/UqossD+jDEN19FImUYaks9BlfXDa2Gdf6sTcX1gJeWKfY/4EF hOj1nhBD6aK9Mn7XuGiAPBS4asbmW0F3PHdhZEFWF841JIF/hejMbeNCBLqDFrkK2N 8pycFcmZFGGubY4RPyGiF2mg9RAu4FxhoWo4yvm69iXkqOYQZY/a9egL+wa4ICIpHo K6W/ISp1Hz/QQ== From: Jisheng Zhang To: Greg Kroah-Hartman , Rob Herring , Krzysztof Kozlowski , Paul Walmsley , Palmer Dabbelt , Albert Ou , Jiri Slaby Cc: linux-serial@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Subject: [PATCH 2/7] serial: bflb_uart: add Bouffalolab UART Driver Date: Sun, 20 Nov 2022 16:21:09 +0800 Message-Id: <20221120082114.3030-3-jszhang@kernel.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20221120082114.3030-1-jszhang@kernel.org> References: <20221120082114.3030-1-jszhang@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221120_003119_744361_627BB8AD X-CRM114-Status: GOOD ( 25.66 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Add the driver for Bouffalolab UART IP which is found in Bouffalolab SoCs such as bl808. UART driver probe will create path named "/dev/ttySx". Signed-off-by: Jisheng Zhang --- drivers/tty/serial/Kconfig | 18 + drivers/tty/serial/Makefile | 1 + drivers/tty/serial/bflb_uart.c | 659 +++++++++++++++++++++++++++++++ include/uapi/linux/serial_core.h | 3 + 4 files changed, 681 insertions(+) create mode 100644 drivers/tty/serial/bflb_uart.c diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index 434f83168546..056a8144e2cc 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -179,6 +179,24 @@ config SERIAL_ATMEL_TTYAT Say Y if you have an external 8250/16C550 UART. If unsure, say N. +config SERIAL_BFLB + tristate "Bouffalolab serial port support" + select SERIAL_CORE + depends on COMMON_CLK + help + This enables the driver for the Bouffalolab's serial. + +config SERIAL_BFLB_CONSOLE + bool "Support for console on Bouffalolab serial port" + depends on SERIAL_BFLB + select SERIAL_CORE_CONSOLE + select SERIAL_EARLYCON + help + Say Y here if you wish to use a Bouffalolab UART 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) as /dev/ttySn. + config SERIAL_KGDB_NMI bool "Serial console over KGDB NMI debugger port" depends on KGDB_SERIAL_CONSOLE diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile index 238a9557b487..8509cdc11d87 100644 --- a/drivers/tty/serial/Makefile +++ b/drivers/tty/serial/Makefile @@ -25,6 +25,7 @@ obj-$(CONFIG_SERIAL_8250) += 8250/ obj-$(CONFIG_SERIAL_AMBA_PL010) += amba-pl010.o obj-$(CONFIG_SERIAL_AMBA_PL011) += amba-pl011.o +obj-$(CONFIG_SERIAL_BFLB) += bflb_uart.o obj-$(CONFIG_SERIAL_CLPS711X) += clps711x.o obj-$(CONFIG_SERIAL_PXA_NON8250) += pxa.o obj-$(CONFIG_SERIAL_SA1100) += sa1100.o diff --git a/drivers/tty/serial/bflb_uart.c b/drivers/tty/serial/bflb_uart.c new file mode 100644 index 000000000000..65f98ccf8fa8 --- /dev/null +++ b/drivers/tty/serial/bflb_uart.c @@ -0,0 +1,659 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Based on bflb_uart.c, by Bouffalolab team + * + * Copyright (C) 2022 Jisheng Zhang + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define UART_UTX_CONFIG 0x00 +#define UART_CR_UTX_EN BIT(0) +#define UART_CR_UTX_CTS_EN BIT(1) +#define UART_CR_UTX_FRM_EN BIT(2) +#define UART_CR_UTX_PRT_EN BIT(4) +#define UART_CR_UTX_PRT_SEL BIT(5) +#define UART_CR_UTX_BIT_CNT_D_SFT 8 +#define UART_CR_UTX_BIT_CNT_D_MSK GENMASK(10, 8) +#define UART_CR_UTX_BIT_CNT_P_SFT 11 +#define UART_CR_UTX_BIT_CNT_P_MSK GENMASK(12, 11) +#define UART_URX_CONFIG 0x04 +#define UART_CR_URX_EN BIT(0) +#define UART_CR_URX_PRT_EN BIT(4) +#define UART_CR_URX_PRT_SEL BIT(5) +#define UART_CR_URX_BIT_CNT_D_SFT 8 +#define UART_CR_URX_BIT_CNT_D_MSK GENMASK(10, 8) +#define UART_BIT_PRD 0x08 +#define UART_CR_UTX_BIT_PRD GENMASK(15, 0) +#define UART_CR_URX_BIT_PRD GENMASK(31, 16) +#define UART_DATA_CONFIG 0x0c +#define UART_CR_UART_BIT_INV BIT(0) +#define UART_URX_RTO_TIMER 0x18 +#define UART_CR_URX_RTO_VALUE_MSK GENMASK(7, 0) +#define UART_SW_MODE 0x1c +#define UART_INT_STS (0x20) +#define UART_UTX_END_INT BIT(0) +#define UART_URX_END_INT BIT(1) +#define UART_UTX_FIFO_INT BIT(2) +#define UART_URX_FIFO_INT BIT(3) +#define UART_URX_RTO_INT BIT(4) +#define UART_URX_PCE_INT BIT(5) +#define UART_UTX_FER_INT BIT(6) +#define UART_URX_FER_INT BIT(7) +#define UART_URX_LSE_INT BIT(8) +#define UART_INT_MASK 0x24 +#define UART_INT_CLEAR 0x28 +#define UART_INT_EN 0x2c +#define UART_STATUS 0x30 +#define UART_STS_UTX_BUS_BUSY BIT(0) +#define UART_FIFO_CONFIG_0 (0x80) +#define UART_DMA_TX_EN BIT(0) +#define UART_DMA_RX_EN BIT(1) +#define UART_TX_FIFO_CLR BIT(2) +#define UART_RX_FIFO_CLR BIT(3) +#define UART_TX_FIFO_OVERFLOW BIT(4) +#define UART_TX_FIFO_UNDERFLOW BIT(5) +#define UART_RX_FIFO_OVERFLOW BIT(6) +#define UART_RX_FIFO_UNDERFLOW BIT(7) +#define UART_FIFO_CONFIG_1 (0x84) +#define UART_TX_FIFO_CNT_SFT 0 +#define UART_TX_FIFO_CNT_MSK GENMASK(5, 0) +#define UART_RX_FIFO_CNT_MSK GENMASK(13, 8) +#define UART_TX_FIFO_TH_SFT 16 +#define UART_TX_FIFO_TH_MSK GENMASK(20, 16) +#define UART_RX_FIFO_TH_SFT 24 +#define UART_RX_FIFO_TH_MSK GENMASK(28, 24) +#define UART_FIFO_WDATA 0x88 +#define UART_FIFO_RDATA 0x8c +#define UART_FIFO_RDATA_MSK GENMASK(7, 0) + +#define BFLB_UART_MAXPORTS 8 +#define BFLB_UART_BAUD 2000000 +#define BFLB_UART_RX_FIFO_TH 7 + +struct bflb_uart_port { + struct uart_port port; + struct clk *clk; +}; + +static struct bflb_uart_port *bflb_uart_ports[BFLB_UART_MAXPORTS]; + +static inline u32 rdl(struct uart_port *port, u32 reg) +{ + return readl_relaxed(port->membase + reg); +} + +static inline void wrl(struct uart_port *port, u32 reg, u32 value) +{ + writel_relaxed(value, port->membase + reg); +} + +static inline void wrb(struct uart_port *port, u32 reg, u8 value) +{ + writeb_relaxed(value, port->membase + reg); +} + +static unsigned int bflb_uart_tx_empty(struct uart_port *port) +{ + return (rdl(port, UART_FIFO_CONFIG_1) & UART_TX_FIFO_CNT_MSK) ? TIOCSER_TEMT : 0; +} + +static unsigned int bflb_uart_get_mctrl(struct uart_port *port) +{ + return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; +} + +static void bflb_uart_set_mctrl(struct uart_port *port, unsigned int sigs) +{ +} + +static void bflb_uart_start_tx(struct uart_port *port) +{ + u32 val; + + val = rdl(port, UART_UTX_CONFIG); + val |= UART_CR_UTX_EN; + wrl(port, UART_UTX_CONFIG, val); + + val = rdl(port, UART_INT_MASK); + val &= ~UART_UTX_END_INT; + wrl(port, UART_INT_MASK, val); + + val = rdl(port, UART_FIFO_CONFIG_1); + val &= ~UART_TX_FIFO_TH_MSK; + val |= 15 << UART_TX_FIFO_TH_SFT; + wrl(port, UART_FIFO_CONFIG_1, val); + + val = rdl(port, UART_INT_MASK); + val &= ~UART_UTX_FIFO_INT; + wrl(port, UART_INT_MASK, val); +} + +static void bflb_uart_stop_tx(struct uart_port *port) +{ + u32 val; + + val = rdl(port, UART_INT_MASK); + val |= UART_UTX_END_INT | UART_UTX_FIFO_INT; + wrl(port, UART_INT_MASK, val); +} + +static void bflb_uart_stop_rx(struct uart_port *port) +{ + u32 val; + + val = rdl(port, UART_URX_CONFIG); + val &= ~UART_CR_URX_EN; + wrl(port, UART_URX_CONFIG, val); + + val = rdl(port, UART_INT_MASK); + val |= UART_URX_FIFO_INT | UART_URX_RTO_INT | + UART_URX_FER_INT; + wrl(port, UART_INT_MASK, val); +} + +static void bflb_uart_break_ctl(struct uart_port *port, int break_state) +{ +} + +static void bflb_uart_set_termios(struct uart_port *port, + struct ktermios *termios, + const struct ktermios *old) +{ + unsigned long flags; + u32 valt, valr, val; + unsigned int baud, min; + + valt = valr = 0; + + spin_lock_irqsave(&port->lock, flags); + + /* set data length */ + val = tty_get_char_size(termios->c_cflag) - 1; + valt |= (val << UART_CR_UTX_BIT_CNT_D_SFT); + + /* calculate parity */ + termios->c_cflag &= ~CMSPAR; /* no support mark/space */ + if (termios->c_cflag & PARENB) { + valt |= UART_CR_UTX_PRT_EN; + if (termios->c_cflag & PARODD) + valr |= UART_CR_UTX_PRT_SEL; + } + + valr = valt; + + /* calculate stop bits */ + if (termios->c_cflag & CSTOPB) + val = 2; + else + val = 1; + valt |= (val << UART_CR_UTX_BIT_CNT_P_SFT); + + /* flow control */ + if (termios->c_cflag & CRTSCTS) + valt |= UART_CR_UTX_CTS_EN; + + /* enable TX freerunning mode */ + valt |= UART_CR_UTX_FRM_EN; + + valt |= UART_CR_UTX_EN; + valr |= UART_CR_URX_EN; + + wrl(port, UART_UTX_CONFIG, valt); + wrl(port, UART_URX_CONFIG, valr); + + min = port->uartclk / (UART_CR_UTX_BIT_PRD + 1); + baud = uart_get_baud_rate(port, termios, old, min, 4000000); + + val = DIV_ROUND_CLOSEST(port->uartclk, baud) - 1; + val &= UART_CR_UTX_BIT_PRD; + val |= (val << 16); + wrl(port, UART_BIT_PRD, val); + + uart_update_timeout(port, termios->c_cflag, baud); + + spin_unlock_irqrestore(&port->lock, flags); +} + +static void bflb_uart_rx_chars(struct uart_port *port) +{ + unsigned char ch, flag; + unsigned long status; + + while ((status = rdl(port, UART_FIFO_CONFIG_1)) & UART_RX_FIFO_CNT_MSK) { + ch = rdl(port, UART_FIFO_RDATA) & UART_FIFO_RDATA_MSK; + flag = TTY_NORMAL; + port->icount.rx++; + + if (uart_handle_sysrq_char(port, ch)) + continue; + uart_insert_char(port, 0, 0, ch, flag); + } + + spin_unlock(&port->lock); + tty_flip_buffer_push(&port->state->port); + spin_lock(&port->lock); +} + +static void bflb_uart_tx_chars(struct uart_port *port) +{ + struct circ_buf *xmit = &port->state->xmit; + unsigned int pending, count; + + if (port->x_char) { + /* Send special char - probably flow control */ + wrl(port, UART_FIFO_WDATA, port->x_char); + port->x_char = 0; + port->icount.tx++; + return; + } + + pending = uart_circ_chars_pending(xmit); + if (pending > 0) { + count = (rdl(port, UART_FIFO_CONFIG_1) & + UART_TX_FIFO_CNT_MSK) >> UART_TX_FIFO_CNT_SFT; + if (count > pending) + count = pending; + if (count > 0) { + pending -= count; + while (count--) { + wrl(port, UART_FIFO_WDATA, xmit->buf[xmit->tail]); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + port->icount.tx++; + } + if (pending < WAKEUP_CHARS) + uart_write_wakeup(port); + } + } + + if (pending == 0) + bflb_uart_stop_tx(port); +} + +static irqreturn_t bflb_uart_interrupt(int irq, void *data) +{ + struct uart_port *port = data; + u32 isr, val; + + isr = rdl(port, UART_INT_STS); + wrl(port, UART_INT_CLEAR, isr); + + isr &= ~rdl(port, UART_INT_MASK); + + spin_lock(&port->lock); + + if (isr & UART_URX_FER_INT) { + /* RX FIFO error interrupt */ + val = rdl(port, UART_FIFO_CONFIG_0); + if (val & UART_RX_FIFO_OVERFLOW) + port->icount.overrun++; + + val |= UART_RX_FIFO_CLR; + wrl(port, UART_FIFO_CONFIG_0, val); + } + + if (isr & (UART_URX_FIFO_INT | UART_URX_RTO_INT)) { + bflb_uart_rx_chars(port); + } + if (isr & (UART_UTX_FIFO_INT | UART_UTX_END_INT)) { + bflb_uart_tx_chars(port); + } + + spin_unlock(&port->lock); + + return IRQ_RETVAL(isr); +} + +static void bflb_uart_config_port(struct uart_port *port, int flags) +{ + u32 val; + + port->type = PORT_BFLB; + + /* Clear mask, so no surprise interrupts. */ + val = rdl(port, UART_INT_MASK); + val |= UART_UTX_END_INT; + val |= UART_UTX_FIFO_INT; + val |= UART_URX_FIFO_INT; + val |= UART_URX_RTO_INT; + val |= UART_URX_FER_INT; + wrl(port, UART_INT_MASK, val); +} + +static int bflb_uart_startup(struct uart_port *port) +{ + unsigned long flags; + int ret; + u32 val; + + ret = devm_request_irq(port->dev, port->irq, bflb_uart_interrupt, + IRQF_SHARED, port->name, port); + if (ret) { + dev_err(port->dev, "fail to request serial irq %d, ret=%d\n", + port->irq, ret); + return ret; + } + + spin_lock_irqsave(&port->lock, flags); + + val = rdl(port, UART_INT_MASK); + val |= 0xfff; + wrl(port, UART_INT_MASK, val); + + wrl(port, UART_DATA_CONFIG, 0); + wrl(port, UART_SW_MODE, 0); + wrl(port, UART_URX_RTO_TIMER, 0x4f); + + val = rdl(port, UART_FIFO_CONFIG_1); + val &= ~UART_RX_FIFO_TH_MSK; + val |= BFLB_UART_RX_FIFO_TH << UART_RX_FIFO_TH_SFT; + wrl(port, UART_FIFO_CONFIG_1, val); + + /* Unmask RX interrupts now */ + val = rdl(port, UART_INT_MASK); + val &= ~UART_URX_FIFO_INT; + val &= ~UART_URX_RTO_INT; + val &= ~UART_URX_FER_INT; + wrl(port, UART_INT_MASK, val); + + val = rdl(port, UART_UTX_CONFIG); + val |= UART_CR_UTX_EN; + wrl(port, UART_UTX_CONFIG, val); + val = rdl(port, UART_URX_CONFIG); + val |= UART_CR_URX_EN; + wrl(port, UART_URX_CONFIG, val); + + spin_unlock_irqrestore(&port->lock, flags); + + return 0; +} + +static void bflb_uart_shutdown(struct uart_port *port) +{ + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + /* mask all interrupts now */ + wrl(port, UART_INT_MASK, UART_UTX_END_INT | UART_URX_END_INT); + spin_unlock_irqrestore(&port->lock, flags); +} + +static const char *bflb_uart_type(struct uart_port *port) +{ + return (port->type == PORT_BFLB) ? "BFLB UART" : NULL; +} + +static int bflb_uart_request_port(struct uart_port *port) +{ + /* UARTs always present */ + return 0; +} + +static void bflb_uart_release_port(struct uart_port *port) +{ + /* Nothing to release... */ +} + +static int bflb_uart_verify_port(struct uart_port *port, + struct serial_struct *ser) +{ + if (ser->type != PORT_UNKNOWN && ser->type != PORT_BFLB) + return -EINVAL; + return 0; +} + +static const struct uart_ops bflb_uart_ops = { + .tx_empty = bflb_uart_tx_empty, + .get_mctrl = bflb_uart_get_mctrl, + .set_mctrl = bflb_uart_set_mctrl, + .start_tx = bflb_uart_start_tx, + .stop_tx = bflb_uart_stop_tx, + .stop_rx = bflb_uart_stop_rx, + .break_ctl = bflb_uart_break_ctl, + .startup = bflb_uart_startup, + .shutdown = bflb_uart_shutdown, + .set_termios = bflb_uart_set_termios, + .type = bflb_uart_type, + .request_port = bflb_uart_request_port, + .release_port = bflb_uart_release_port, + .config_port = bflb_uart_config_port, + .verify_port = bflb_uart_verify_port, +}; + +#ifdef CONFIG_SERIAL_BFLB_CONSOLE +static void bflb_console_putchar(struct uart_port *port, unsigned char ch) +{ + while (!(rdl(port, UART_FIFO_CONFIG_1) & UART_TX_FIFO_CNT_MSK)) + cpu_relax(); + wrb(port, UART_FIFO_WDATA, ch); +} + +/* + * Interrupts are disabled on entering + */ +static void bflb_uart_console_write(struct console *co, const char *s, + u_int count) +{ + struct uart_port *port = &bflb_uart_ports[co->index]->port; + u32 status, reg, mask; + + /* save then disable interrupts */ + mask = rdl(port, UART_INT_MASK); + reg = -1; + wrl(port, UART_INT_MASK, reg); + + /* Make sure that tx is enabled */ + reg = rdl(port, UART_UTX_CONFIG); + reg |= UART_CR_UTX_EN; + wrl(port, UART_UTX_CONFIG, reg); + + uart_console_write(port, s, count, bflb_console_putchar); + + /* wait for TX done */ + do { + status = rdl(port, UART_STATUS); + } while ((status & UART_STS_UTX_BUS_BUSY)); + + /* restore IRQ mask */ + wrl(port, UART_INT_MASK, mask); +} + +static int bflb_uart_console_setup(struct console *co, char *options) +{ + struct uart_port *port; + struct bflb_uart_port *bp; + int baud = BFLB_UART_BAUD; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + u32 val; + + if (co->index >= BFLB_UART_MAXPORTS || co->index < 0) + return -EINVAL; + + bp = bflb_uart_ports[co->index]; + if (!bp) + /* Port not initialized yet - delay setup */ + return -ENODEV; + + port = &bp->port; + + val = rdl(port, UART_UTX_CONFIG); + val |= UART_CR_UTX_EN; + wrl(port, UART_UTX_CONFIG, val); + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + + return uart_set_options(port, co, baud, parity, bits, flow); +} + +static struct uart_driver bflb_uart_driver; +static struct console bflb_uart_console = { + .name = "ttyS", + .write = bflb_uart_console_write, + .device = uart_console_device, + .setup = bflb_uart_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &bflb_uart_driver, +}; + +static int __init bflb_uart_console_init(void) +{ + register_console(&bflb_uart_console); + return 0; +} +console_initcall(bflb_uart_console_init); + +#define BFLB_UART_CONSOLE (&bflb_uart_console) + +static void bflb_uart_earlycon_write(struct console *co, const char *s, + unsigned int count) +{ + struct earlycon_device *dev = co->data; + + uart_console_write(&dev->port, s, count, bflb_console_putchar); +} + +static int __init bflb_uart_earlycon_setup(struct earlycon_device *dev, + const char *options) +{ + if (!dev->port.membase) + return -ENODEV; + + dev->con->write = bflb_uart_earlycon_write; + + return 0; +} +OF_EARLYCON_DECLARE(bflb_uart, "bouffalolab,uart", bflb_uart_earlycon_setup); + +#else + +#define BFLB_UART_CONSOLE NULL + +#endif /* CONFIG_SERIAL_BFLB_CONSOLE */ + +static struct uart_driver bflb_uart_driver = { + .owner = THIS_MODULE, + .driver_name = "bflb_uart", + .dev_name = "ttyS", + .nr = BFLB_UART_MAXPORTS, + .cons = BFLB_UART_CONSOLE, +}; + +static int bflb_uart_probe(struct platform_device *pdev) +{ + struct uart_port *port; + struct bflb_uart_port *bp; + struct resource *res; + int index, irq; + + index = of_alias_get_id(pdev->dev.of_node, "serial"); + if (unlikely(index < 0 || index >= BFLB_UART_MAXPORTS)) { + dev_err(&pdev->dev, "got a wrong serial alias id %d\n", index); + return -EINVAL; + } + + bp = devm_kzalloc(&pdev->dev, sizeof(*bp), GFP_KERNEL); + if (!bp) + return -ENOMEM; + + bflb_uart_ports[index] = bp; + platform_set_drvdata(pdev, bp); + port = &bp->port; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + port->membase = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(port->membase)) + return PTR_ERR(port->membase); + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + port->mapbase = res->start; + port->irq = irq; + port->line = index; + port->type = PORT_BFLB; + port->iotype = UPIO_MEM; + port->fifosize = 32; + port->ops = &bflb_uart_ops; + port->flags = UPF_BOOT_AUTOCONF; + port->dev = &pdev->dev; + port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_BFLB_CONSOLE); + + bp->clk = devm_clk_get_enabled(&pdev->dev, NULL); + if (IS_ERR(bp->clk)) + return PTR_ERR(bp->clk); + port->uartclk = clk_get_rate(bp->clk); + + return uart_add_one_port(&bflb_uart_driver, port); +} + +static int bflb_uart_remove(struct platform_device *pdev) +{ + struct bflb_uart_port *bp = platform_get_drvdata(pdev); + + uart_remove_one_port(&bflb_uart_driver, &bp->port); + bflb_uart_ports[bp->port.line] = NULL; + + return 0; +} + +static const struct of_device_id bflb_uart_match[] = { + { + .compatible = "bouffalolab,uart", + }, + {}, +}; +MODULE_DEVICE_TABLE(of, bflb_uart_match); + +static struct platform_driver bflb_uart_platform_driver = { + .probe = bflb_uart_probe, + .remove = bflb_uart_remove, + .driver = { + .name = "bflb_uart", + .of_match_table = of_match_ptr(bflb_uart_match), + }, +}; + +static int __init bflb_uart_init(void) +{ + int ret; + + ret = uart_register_driver(&bflb_uart_driver); + if (ret) + return ret; + + ret = platform_driver_register(&bflb_uart_platform_driver); + if (ret) + uart_unregister_driver(&bflb_uart_driver); + + return ret; +} + +static void __exit bflb_uart_exit(void) +{ + platform_driver_unregister(&bflb_uart_platform_driver); + uart_unregister_driver(&bflb_uart_driver); +} + +module_init(bflb_uart_init); +module_exit(bflb_uart_exit); + +MODULE_DESCRIPTION("Bouffalolab UART driver"); +MODULE_AUTHOR("Jisheng Zhang "); +MODULE_LICENSE("GPL"); diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h index 3ba34d8378bd..dabbb5ea2857 100644 --- a/include/uapi/linux/serial_core.h +++ b/include/uapi/linux/serial_core.h @@ -276,4 +276,7 @@ /* Sunplus UART */ #define PORT_SUNPLUS 123 +/* Bouffalolab UART */ +#define PORT_BFLB 124 + #endif /* _UAPILINUX_SERIAL_CORE_H */