Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752238AbbEXPaY (ORCPT ); Sun, 24 May 2015 11:30:24 -0400 Received: from mailapp01.imgtec.com ([195.59.15.196]:65401 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751934AbbEXPaU (ORCPT ); Sun, 24 May 2015 11:30:20 -0400 From: Paul Burton To: CC: Paul Burton , Greg Kroah-Hartman , Jiri Slaby , Lars-Peter Clausen , , Sebastian Andrzej Siewior , Peter Hurley , Alan Cox , , Matthias Brugger , Ricardo Ribalda Delgado , Tony Lindgren , John Crispin Subject: [PATCH v5 34/37] serial: 8250_ingenic: support for Ingenic SoC UARTs Date: Sun, 24 May 2015 16:11:44 +0100 Message-ID: <1432480307-23789-35-git-send-email-paul.burton@imgtec.com> X-Mailer: git-send-email 2.4.1 In-Reply-To: <1432480307-23789-1-git-send-email-paul.burton@imgtec.com> References: <1432480307-23789-1-git-send-email-paul.burton@imgtec.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [192.168.159.140] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 10383 Lines: 346 Introduce a driver suitable for use with the UARTs present in Ingenic SoCs such as the JZ4740 & JZ4780. These are described as being ns16550 compatible but aren't quite - they require the setting of an extra bit in the FCR register to enable the UART module. The serial_out implementation is the same as that in arch/mips/jz4740/serial.c - which will shortly be removed. Signed-off-by: Paul Burton Cc: Greg Kroah-Hartman Cc: Jiri Slaby Cc: Lars-Peter Clausen Cc: linux-serial@vger.kernel.org --- Changes in v5: - Support setting the port line based upon DT aliases, just as of_serial does, in order to allow device numbering to be specified by the DT. Changes in v4: None Changes in v3: - s/jz47xx/ingenic/ to reflect Ingenic's naming change for newer SoCs. - Support JZ4775. - Depend on SERIAL_8250_CONSOLE rather than selecting SERIAL_CORE_CONSOLE. - Read the UART clock for early consoles from the DT, using libfdt to find the node for the fixed rate external clock which drives the UART in all known Ingenic SoCs, rather than relying upon a hardcoded definition for BASE_BAUD. Changes in v2: - Remove FSF address (ZubairLK). - Select SERIAL_CORE_CONSOLE (ZubairLK). drivers/tty/serial/8250/8250_ingenic.c | 266 +++++++++++++++++++++++++++++++++ drivers/tty/serial/8250/Kconfig | 9 ++ drivers/tty/serial/8250/Makefile | 3 + 3 files changed, 278 insertions(+) create mode 100644 drivers/tty/serial/8250/8250_ingenic.c diff --git a/drivers/tty/serial/8250/8250_ingenic.c b/drivers/tty/serial/8250/8250_ingenic.c new file mode 100644 index 0000000..21bf81f --- /dev/null +++ b/drivers/tty/serial/8250/8250_ingenic.c @@ -0,0 +1,266 @@ +/* + * Copyright (C) 2010 Lars-Peter Clausen + * Copyright (C) 2015 Imagination Technologies + * + * Ingenic SoC UART support + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct ingenic_uart_data { + struct clk *clk_module; + struct clk *clk_baud; + int line; +}; + +#define UART_FCR_UME BIT(4) + +static struct earlycon_device *early_device; + +static uint8_t __init early_in(struct uart_port *port, int offset) +{ + return readl(port->membase + (offset << 2)); +} + +static void __init early_out(struct uart_port *port, int offset, uint8_t value) +{ + writel(value, port->membase + (offset << 2)); +} + +static void __init ingenic_early_console_putc(struct uart_port *port, int c) +{ + uint8_t lsr; + + do { + lsr = early_in(port, UART_LSR); + } while ((lsr & UART_LSR_TEMT) == 0); + + early_out(port, UART_TX, c); +} + +static void __init ingenic_early_console_write(struct console *console, + const char *s, unsigned int count) +{ + uart_console_write(&early_device->port, s, count, + ingenic_early_console_putc); +} + +static void __init ingenic_early_console_setup_clock(struct earlycon_device *dev) +{ + void *fdt = initial_boot_params; + const __be32 *prop; + int offset; + + offset = fdt_path_offset(fdt, "/ext"); + if (offset < 0) + return; + + prop = fdt_getprop(fdt, offset, "clock-frequency", NULL); + if (!prop) + return; + + dev->port.uartclk = be32_to_cpup(prop); +} + +static int __init ingenic_early_console_setup(struct earlycon_device *dev, + const char *opt) +{ + struct uart_port *port = &dev->port; + unsigned int baud, divisor; + + if (!dev->port.membase) + return -ENODEV; + + ingenic_early_console_setup_clock(dev); + + baud = dev->baud ?: 115200; + divisor = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud); + + early_out(port, UART_IER, 0); + early_out(port, UART_LCR, UART_LCR_DLAB | UART_LCR_WLEN8); + early_out(port, UART_DLL, 0); + early_out(port, UART_DLM, 0); + early_out(port, UART_LCR, UART_LCR_WLEN8); + early_out(port, UART_FCR, UART_FCR_UME | UART_FCR_CLEAR_XMIT | + UART_FCR_CLEAR_RCVR | UART_FCR_ENABLE_FIFO); + early_out(port, UART_MCR, UART_MCR_RTS | UART_MCR_DTR); + + early_out(port, UART_LCR, UART_LCR_DLAB | UART_LCR_WLEN8); + early_out(port, UART_DLL, divisor & 0xff); + early_out(port, UART_DLM, (divisor >> 8) & 0xff); + early_out(port, UART_LCR, UART_LCR_WLEN8); + + early_device = dev; + dev->con->write = ingenic_early_console_write; + + return 0; +} + +EARLYCON_DECLARE(jz4740_uart, ingenic_early_console_setup); +OF_EARLYCON_DECLARE(jz4740_uart, "ingenic,jz4740-uart", + ingenic_early_console_setup); + +EARLYCON_DECLARE(jz4775_uart, ingenic_early_console_setup); +OF_EARLYCON_DECLARE(jz4775_uart, "ingenic,jz4775-uart", + ingenic_early_console_setup); + +EARLYCON_DECLARE(jz4780_uart, ingenic_early_console_setup); +OF_EARLYCON_DECLARE(jz4780_uart, "ingenic,jz4780-uart", + ingenic_early_console_setup); + +static void ingenic_uart_serial_out(struct uart_port *p, int offset, int value) +{ + switch (offset) { + case UART_FCR: + /* UART module enable */ + value |= UART_FCR_UME; + break; + + case UART_IER: + value |= (value & 0x4) << 2; + break; + + default: + break; + } + + writeb(value, p->membase + (offset << p->regshift)); +} + +static int ingenic_uart_probe(struct platform_device *pdev) +{ + struct uart_8250_port uart = {}; + struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); + struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + struct ingenic_uart_data *data; + int err, line; + + if (!regs || !irq) { + dev_err(&pdev->dev, "no registers/irq defined\n"); + return -EINVAL; + } + + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + spin_lock_init(&uart.port.lock); + uart.port.type = PORT_16550; + uart.port.flags = UPF_SKIP_TEST | UPF_IOREMAP | UPF_FIXED_TYPE; + uart.port.iotype = UPIO_MEM; + uart.port.mapbase = regs->start; + uart.port.regshift = 2; + uart.port.serial_out = ingenic_uart_serial_out; + uart.port.irq = irq->start; + uart.port.dev = &pdev->dev; + + /* Check for a fixed line number */ + line = of_alias_get_id(pdev->dev.of_node, "serial"); + if (line >= 0) + uart.port.line = line; + + uart.port.membase = devm_ioremap(&pdev->dev, regs->start, + resource_size(regs)); + if (!uart.port.membase) + return -ENOMEM; + + data->clk_module = devm_clk_get(&pdev->dev, "module"); + if (IS_ERR(data->clk_module)) { + err = PTR_ERR(data->clk_module); + if (err != -EPROBE_DEFER) + dev_err(&pdev->dev, + "unable to get module clock: %d\n", err); + return err; + } + + data->clk_baud = devm_clk_get(&pdev->dev, "baud"); + if (IS_ERR(data->clk_baud)) { + err = PTR_ERR(data->clk_baud); + if (err != -EPROBE_DEFER) + dev_err(&pdev->dev, + "unable to get baud clock: %d\n", err); + return err; + } + + err = clk_prepare_enable(data->clk_module); + if (err) { + dev_err(&pdev->dev, "could not enable module clock: %d\n", err); + goto out; + } + + err = clk_prepare_enable(data->clk_baud); + if (err) { + dev_err(&pdev->dev, "could not enable baud clock: %d\n", err); + goto out_disable_moduleclk; + } + uart.port.uartclk = clk_get_rate(data->clk_baud); + + data->line = serial8250_register_8250_port(&uart); + if (data->line < 0) { + err = data->line; + goto out_disable_baudclk; + } + + platform_set_drvdata(pdev, data); + return 0; + +out_disable_baudclk: + clk_disable_unprepare(data->clk_baud); +out_disable_moduleclk: + clk_disable_unprepare(data->clk_module); +out: + return err; +} + +static int ingenic_uart_remove(struct platform_device *pdev) +{ + struct ingenic_uart_data *data = platform_get_drvdata(pdev); + + serial8250_unregister_port(data->line); + clk_disable_unprepare(data->clk_module); + clk_disable_unprepare(data->clk_baud); + return 0; +} + +static const struct of_device_id of_match[] = { + { .compatible = "ingenic,jz4740-uart" }, + { .compatible = "ingenic,jz4775-uart" }, + { .compatible = "ingenic,jz4780-uart" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, of_match); + +static struct platform_driver ingenic_uart_platform_driver = { + .driver = { + .name = "ingenic-uart", + .owner = THIS_MODULE, + .of_match_table = of_match, + }, + .probe = ingenic_uart_probe, + .remove = ingenic_uart_remove, +}; + +module_platform_driver(ingenic_uart_platform_driver); + +MODULE_AUTHOR("Paul Burton"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Ingenic SoC UART driver"); diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig index c350703..43330ea 100644 --- a/drivers/tty/serial/8250/Kconfig +++ b/drivers/tty/serial/8250/Kconfig @@ -342,3 +342,12 @@ config SERIAL_8250_MT6577 help If you have a Mediatek based board and want to use the serial port, say Y to this option. If unsure, say N. + +config SERIAL_8250_INGENIC + bool "Support for Ingenic SoC serial ports" + depends on SERIAL_8250_CONSOLE && OF_FLATTREE + select LIBFDT + select SERIAL_EARLYCON + help + If you have a system using an Ingenic SoC and wish to make use of + its UARTs, say Y to this option. If unsure, say N. diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile index 31e7cdc..98fba26 100644 --- a/drivers/tty/serial/8250/Makefile +++ b/drivers/tty/serial/8250/Makefile @@ -23,3 +23,6 @@ obj-$(CONFIG_SERIAL_8250_EM) += 8250_em.o obj-$(CONFIG_SERIAL_8250_OMAP) += 8250_omap.o obj-$(CONFIG_SERIAL_8250_FINTEK) += 8250_fintek.o obj-$(CONFIG_SERIAL_8250_MT6577) += 8250_mtk.o +obj-$(CONFIG_SERIAL_8250_INGENIC) += 8250_ingenic.o + +CFLAGS_8250_ingenic.o += -I$(srctree)/scripts/dtc/libfdt -- 2.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/