| From 851dd6ac01a254a7c6e14a75c0cd0c8aec2d542b Mon Sep 17 00:00:00 2001 |
| From: Magnus Damm <damm@opensource.se> |
| Date: Thu, 3 May 2012 21:13:09 +0900 |
| Subject: serial8250-em: Emma Mobile UART driver V2 |
| |
| This is V2 of the Emma Mobile 8250 platform driver. |
| |
| The hardware itself has according to the data sheet |
| up to 64 byte FIFOs but at this point we only make |
| use of the 16550 compatible mode. |
| |
| To support this piece of hardware the common UART |
| registers need to be remapped, and the access size |
| differences need to be handled. |
| |
| The DLL and DLM registers can due to offset collision |
| not be remapped easily, and because of that this |
| driver makes use of ->dl_read() and ->dl_write() |
| callbacks. This in turn requires a registration |
| function that takes 8250-specific paramenters. |
| |
| Future potential enhancements include DT support, |
| early platform driver console and fine grained PM. |
| |
| Signed-off-by: Magnus Damm <damm@opensource.se> |
| Acked-by: Alan Cox <alan@linux.intel.com> |
| Acked-by: Arnd Bergmann <arnd@arndb.de> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| (cherry picked from commit 22886ee96895b7a9f9d06da4dc9420b61b4ef1f7) |
| |
| Conflicts: |
| drivers/tty/serial/8250/Kconfig |
| drivers/tty/serial/8250/Makefile |
| |
| Signed-off-by: Simon Horman <horms@verge.net.au> |
| --- |
| drivers/tty/serial/8250/8250_em.c | 178 +++++++++++++++++++++++++++++++++++++ |
| drivers/tty/serial/8250/Kconfig | 8 ++ |
| drivers/tty/serial/8250/Makefile | 1 + |
| 3 files changed, 187 insertions(+) |
| create mode 100644 drivers/tty/serial/8250/8250_em.c |
| |
| diff --git a/drivers/tty/serial/8250/8250_em.c b/drivers/tty/serial/8250/8250_em.c |
| new file mode 100644 |
| index 0000000..ff42542 |
| --- /dev/null |
| +++ b/drivers/tty/serial/8250/8250_em.c |
| @@ -0,0 +1,178 @@ |
| +/* |
| + * Renesas Emma Mobile 8250 driver |
| + * |
| + * Copyright (C) 2012 Magnus Damm |
| + * |
| + * 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 |
| + * |
| + * This program is distributed in the hope that it will be useful, |
| + * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| + * GNU General Public License for more details. |
| + * |
| + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| + */ |
| + |
| +#include <linux/device.h> |
| +#include <linux/init.h> |
| +#include <linux/io.h> |
| +#include <linux/module.h> |
| +#include <linux/serial_8250.h> |
| +#include <linux/serial_core.h> |
| +#include <linux/serial_reg.h> |
| +#include <linux/platform_device.h> |
| +#include <linux/clk.h> |
| +#include <linux/slab.h> |
| + |
| +#include "8250.h" |
| + |
| +#define UART_DLL_EM 9 |
| +#define UART_DLM_EM 10 |
| + |
| +struct serial8250_em_priv { |
| + struct clk *sclk; |
| + int line; |
| +}; |
| + |
| +static void serial8250_em_serial_out(struct uart_port *p, int offset, int value) |
| +{ |
| + switch (offset) { |
| + case UART_TX: /* TX @ 0x00 */ |
| + writeb(value, p->membase); |
| + break; |
| + case UART_FCR: /* FCR @ 0x0c (+1) */ |
| + case UART_LCR: /* LCR @ 0x10 (+1) */ |
| + case UART_MCR: /* MCR @ 0x14 (+1) */ |
| + case UART_SCR: /* SCR @ 0x20 (+1) */ |
| + writel(value, p->membase + ((offset + 1) << 2)); |
| + break; |
| + case UART_IER: /* IER @ 0x04 */ |
| + value &= 0x0f; /* only 4 valid bits - not Xscale */ |
| + /* fall-through */ |
| + case UART_DLL_EM: /* DLL @ 0x24 (+9) */ |
| + case UART_DLM_EM: /* DLM @ 0x28 (+9) */ |
| + writel(value, p->membase + (offset << 2)); |
| + } |
| +} |
| + |
| +static unsigned int serial8250_em_serial_in(struct uart_port *p, int offset) |
| +{ |
| + switch (offset) { |
| + case UART_RX: /* RX @ 0x00 */ |
| + return readb(p->membase); |
| + case UART_MCR: /* MCR @ 0x14 (+1) */ |
| + case UART_LSR: /* LSR @ 0x18 (+1) */ |
| + case UART_MSR: /* MSR @ 0x1c (+1) */ |
| + case UART_SCR: /* SCR @ 0x20 (+1) */ |
| + return readl(p->membase + ((offset + 1) << 2)); |
| + case UART_IER: /* IER @ 0x04 */ |
| + case UART_IIR: /* IIR @ 0x08 */ |
| + case UART_DLL_EM: /* DLL @ 0x24 (+9) */ |
| + case UART_DLM_EM: /* DLM @ 0x28 (+9) */ |
| + return readl(p->membase + (offset << 2)); |
| + } |
| + return 0; |
| +} |
| + |
| +static int serial8250_em_serial_dl_read(struct uart_8250_port *up) |
| +{ |
| + return serial_in(up, UART_DLL_EM) | serial_in(up, UART_DLM_EM) << 8; |
| +} |
| + |
| +static void serial8250_em_serial_dl_write(struct uart_8250_port *up, int value) |
| +{ |
| + serial_out(up, UART_DLL_EM, value & 0xff); |
| + serial_out(up, UART_DLM_EM, value >> 8 & 0xff); |
| +} |
| + |
| +static int __devinit serial8250_em_probe(struct platform_device *pdev) |
| +{ |
| + struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| + struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); |
| + struct serial8250_em_priv *priv; |
| + struct uart_8250_port up; |
| + int ret = -EINVAL; |
| + |
| + if (!regs || !irq) { |
| + dev_err(&pdev->dev, "missing registers or irq\n"); |
| + goto err0; |
| + } |
| + |
| + priv = kzalloc(sizeof(*priv), GFP_KERNEL); |
| + if (!priv) { |
| + dev_err(&pdev->dev, "unable to allocate private data\n"); |
| + ret = -ENOMEM; |
| + goto err0; |
| + } |
| + |
| + priv->sclk = clk_get(&pdev->dev, "sclk"); |
| + if (!priv->sclk) { |
| + dev_err(&pdev->dev, "unable to get clock\n"); |
| + goto err1; |
| + } |
| + |
| + memset(&up, 0, sizeof(up)); |
| + up.port.mapbase = regs->start; |
| + up.port.irq = irq->start; |
| + up.port.type = PORT_UNKNOWN; |
| + up.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP; |
| + up.port.dev = &pdev->dev; |
| + up.port.private_data = priv; |
| + |
| + clk_enable(priv->sclk); |
| + up.port.uartclk = clk_get_rate(priv->sclk); |
| + |
| + up.port.iotype = UPIO_MEM32; |
| + up.port.serial_in = serial8250_em_serial_in; |
| + up.port.serial_out = serial8250_em_serial_out; |
| + up.dl_read = serial8250_em_serial_dl_read; |
| + up.dl_write = serial8250_em_serial_dl_write; |
| + |
| + ret = serial8250_register_8250_port(&up); |
| + if (ret < 0) { |
| + dev_err(&pdev->dev, "unable to register 8250 port\n"); |
| + goto err2; |
| + } |
| + |
| + priv->line = ret; |
| + platform_set_drvdata(pdev, priv); |
| + return 0; |
| + |
| + err2: |
| + clk_disable(priv->sclk); |
| + clk_put(priv->sclk); |
| + err1: |
| + kfree(priv); |
| + err0: |
| + return ret; |
| +} |
| + |
| +static int __devexit serial8250_em_remove(struct platform_device *pdev) |
| +{ |
| + struct serial8250_em_priv *priv = platform_get_drvdata(pdev); |
| + |
| + serial8250_unregister_port(priv->line); |
| + clk_disable(priv->sclk); |
| + clk_put(priv->sclk); |
| + kfree(priv); |
| + return 0; |
| +} |
| + |
| +static struct platform_driver serial8250_em_platform_driver = { |
| + .driver = { |
| + .name = "serial8250-em", |
| + .owner = THIS_MODULE, |
| + }, |
| + .probe = serial8250_em_probe, |
| + .remove = __devexit_p(serial8250_em_remove), |
| +}; |
| + |
| +module_platform_driver(serial8250_em_platform_driver); |
| + |
| +MODULE_AUTHOR("Magnus Damm"); |
| +MODULE_DESCRIPTION("Renesas Emma Mobile 8250 Driver"); |
| +MODULE_LICENSE("GPL v2"); |
| diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig |
| index b1bb251..7aa3b6c 100644 |
| --- a/drivers/tty/serial/8250/Kconfig |
| +++ b/drivers/tty/serial/8250/Kconfig |
| @@ -266,3 +266,11 @@ config SERIAL_8250_RM9K |
| Selecting this option will add support for the integrated serial |
| port hardware found on MIPS RM9122 and similar processors. |
| If unsure, say N. |
| + |
| +config SERIAL_8250_EM |
| + tristate "Support for Emma Mobile intergrated serial port" |
| + depends on SERIAL_8250 && ARM && HAVE_CLK |
| + help |
| + Selecting this option will add support for the integrated serial |
| + port hardware found on the Emma Mobile line of processors. |
| + If unsure, say N. |
| diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile |
| index c0d0c29..6a70704 100644 |
| --- a/drivers/tty/serial/8250/Makefile |
| +++ b/drivers/tty/serial/8250/Makefile |
| @@ -16,3 +16,4 @@ obj-$(CONFIG_SERIAL_8250_BOCA) += 8250_boca.o |
| obj-$(CONFIG_SERIAL_8250_EXAR_ST16C554) += 8250_exar_st16c554.o |
| obj-$(CONFIG_SERIAL_8250_HUB6) += 8250_hub6.o |
| obj-$(CONFIG_SERIAL_8250_MCA) += 8250_mca.o |
| +obj-$(CONFIG_SERIAL_8250_EM) += 8250_em.o |
| -- |
| 1.7.10.1.362.g242cab3 |
| |