linux/drivers/tty/serial/8250/8250_mtk.c
Linus Torvalds c0f486fde3 More ACPI and power management updates for 3.19-rc1
- Fix a regression in leds-gpio introduced by a recent commit that
    inadvertently changed the name of one of the properties used by
    the driver (Fabio Estevam).
 
  - Fix a regression in the ACPI backlight driver introduced by a
    recent fix that missed one special case that had to be taken
    into account (Aaron Lu).
 
  - Drop the level of some new kernel messages from the ACPI core
    introduced by a recent commit to KERN_DEBUG which they should
    have used from the start and drop some other unuseful KERN_ERR
    messages printed by ACPI (Rafael J Wysocki).
 
  - Revert an incorrect commit modifying the cpupower tool
    (Prarit Bhargava).
 
  - Fix two regressions introduced by recent commits in the OPP
    library and clean up some existing minor issues in that code
    (Viresh Kumar).
 
  - Continue to replace CONFIG_PM_RUNTIME with CONFIG_PM throughout
    the tree (or drop it where that can be done) in order to make
    it possible to eliminate CONFIG_PM_RUNTIME (Rafael J Wysocki,
    Ulf Hansson, Ludovic Desroches).  There will be one more
    "CONFIG_PM_RUNTIME removal" batch after this one, because some
    new uses of it have been introduced during the current merge
    window, but that should be sufficient to finally get rid of it.
 
  - Make the ACPI EC driver more robust against race conditions
    related to GPE handler installation failures (Lv Zheng).
 
  - Prevent the ACPI device PM core code from attempting to
    disable GPEs that it has not enabled which confuses ACPICA
    and makes it report errors unnecessarily (Rafael J Wysocki).
 
  - Add a "force" command line switch to the intel_pstate driver
    to make it possible to override the blacklisting of some
    systems in that driver if needed (Ethan Zhao).
 
  - Improve intel_pstate code documentation and add a MAINTAINERS
    entry for it (Kristen Carlson Accardi).
 
  - Make the ACPI fan driver create cooling device interfaces
    witn names that reflect the IDs of the ACPI device objects
    they are associated with, except for "generic" ACPI fans
    (PNP ID "PNP0C0B").  That's necessary for user space thermal
    management tools to be able to connect the fans with the
    parts of the system they are supposed to be cooling properly.
    From Srinivas Pandruvada.
 
 /
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Merge tag 'pm+acpi-3.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull more ACPI and power management updates from Rafael Wysocki:
 "These are regression fixes (leds-gpio, ACPI backlight driver,
  operating performance points library, ACPI device enumeration
  messages, cpupower tool), other bug fixes (ACPI EC driver, ACPI device
  PM), some cleanups in the operating performance points (OPP)
  framework, continuation of CONFIG_PM_RUNTIME elimination, a couple of
  minor intel_pstate driver changes, a new MAINTAINERS entry for it and
  an ACPI fan driver change needed for better support of thermal
  management in user space.

  Specifics:

   - Fix a regression in leds-gpio introduced by a recent commit that
     inadvertently changed the name of one of the properties used by the
     driver (Fabio Estevam).

   - Fix a regression in the ACPI backlight driver introduced by a
     recent fix that missed one special case that had to be taken into
     account (Aaron Lu).

   - Drop the level of some new kernel messages from the ACPI core
     introduced by a recent commit to KERN_DEBUG which they should have
     used from the start and drop some other unuseful KERN_ERR messages
     printed by ACPI (Rafael J Wysocki).

   - Revert an incorrect commit modifying the cpupower tool (Prarit
     Bhargava).

   - Fix two regressions introduced by recent commits in the OPP library
     and clean up some existing minor issues in that code (Viresh
     Kumar).

   - Continue to replace CONFIG_PM_RUNTIME with CONFIG_PM throughout the
     tree (or drop it where that can be done) in order to make it
     possible to eliminate CONFIG_PM_RUNTIME (Rafael J Wysocki, Ulf
     Hansson, Ludovic Desroches).

     There will be one more "CONFIG_PM_RUNTIME removal" batch after this
     one, because some new uses of it have been introduced during the
     current merge window, but that should be sufficient to finally get
     rid of it.

   - Make the ACPI EC driver more robust against race conditions related
     to GPE handler installation failures (Lv Zheng).

   - Prevent the ACPI device PM core code from attempting to disable
     GPEs that it has not enabled which confuses ACPICA and makes it
     report errors unnecessarily (Rafael J Wysocki).

   - Add a "force" command line switch to the intel_pstate driver to
     make it possible to override the blacklisting of some systems in
     that driver if needed (Ethan Zhao).

   - Improve intel_pstate code documentation and add a MAINTAINERS entry
     for it (Kristen Carlson Accardi).

   - Make the ACPI fan driver create cooling device interfaces witn
     names that reflect the IDs of the ACPI device objects they are
     associated with, except for "generic" ACPI fans (PNP ID "PNP0C0B").

     That's necessary for user space thermal management tools to be able
     to connect the fans with the parts of the system they are supposed
     to be cooling properly.  From Srinivas Pandruvada"

* tag 'pm+acpi-3.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (32 commits)
  MAINTAINERS: add entry for intel_pstate
  ACPI / video: update the skip case for acpi_video_device_in_dod()
  power / PM: Eliminate CONFIG_PM_RUNTIME
  NFC / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  SCSI / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  ACPI / EC: Fix unexpected ec_remove_handlers() invocations
  Revert "tools: cpupower: fix return checks for sysfs_get_idlestate_count()"
  tracing / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  x86 / PM: Replace CONFIG_PM_RUNTIME in io_apic.c
  PM: Remove the SET_PM_RUNTIME_PM_OPS() macro
  mmc: atmel-mci: use SET_RUNTIME_PM_OPS() macro
  PM / Kconfig: Replace PM_RUNTIME with PM in dependencies
  ARM / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  sound / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  phy / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  video / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  tty / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  spi: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  ACPI / PM: Do not disable wakeup GPEs that have not been enabled
  ACPI / utils: Drop error messages from acpi_evaluate_reference()
  ...
2014-12-18 20:28:33 -08:00

295 lines
7.4 KiB
C

/*
* Mediatek 8250 driver.
*
* Copyright (c) 2014 MundoReader S.L.
* Author: Matthias Brugger <matthias.bgg@gmail.com>
*
* 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.
*
* 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.
*/
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/serial_8250.h>
#include <linux/serial_reg.h>
#include "8250.h"
#define UART_MTK_HIGHS 0x09 /* Highspeed register */
#define UART_MTK_SAMPLE_COUNT 0x0a /* Sample count register */
#define UART_MTK_SAMPLE_POINT 0x0b /* Sample point register */
#define MTK_UART_RATE_FIX 0x0d /* UART Rate Fix Register */
struct mtk8250_data {
int line;
struct clk *uart_clk;
};
static void
mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
{
unsigned long flags;
unsigned int baud, quot;
struct uart_8250_port *up =
container_of(port, struct uart_8250_port, port);
serial8250_do_set_termios(port, termios, old);
/*
* Mediatek UARTs use an extra highspeed register (UART_MTK_HIGHS)
*
* We need to recalcualte the quot register, as the claculation depends
* on the vaule in the highspeed register.
*
* Some baudrates are not supported by the chip, so we use the next
* lower rate supported and update termios c_flag.
*
* If highspeed register is set to 3, we need to specify sample count
* and sample point to increase accuracy. If not, we reset the
* registers to their default values.
*/
baud = uart_get_baud_rate(port, termios, old,
port->uartclk / 16 / 0xffff,
port->uartclk / 16);
if (baud <= 115200) {
serial_port_out(port, UART_MTK_HIGHS, 0x0);
quot = uart_get_divisor(port, baud);
} else if (baud <= 576000) {
serial_port_out(port, UART_MTK_HIGHS, 0x2);
/* Set to next lower baudrate supported */
if ((baud == 500000) || (baud == 576000))
baud = 460800;
quot = DIV_ROUND_UP(port->uartclk, 4 * baud);
} else {
serial_port_out(port, UART_MTK_HIGHS, 0x3);
/* Set to highest baudrate supported */
if (baud >= 1152000)
baud = 921600;
quot = DIV_ROUND_UP(port->uartclk, 256 * baud);
}
/*
* Ok, we're now changing the port state. Do it with
* interrupts disabled.
*/
spin_lock_irqsave(&port->lock, flags);
/* set DLAB we have cval saved in up->lcr from the call to the core */
serial_port_out(port, UART_LCR, up->lcr | UART_LCR_DLAB);
serial_dl_write(up, quot);
/* reset DLAB */
serial_port_out(port, UART_LCR, up->lcr);
if (baud > 460800) {
unsigned int tmp;
tmp = DIV_ROUND_CLOSEST(port->uartclk, quot * baud);
serial_port_out(port, UART_MTK_SAMPLE_COUNT, tmp - 1);
serial_port_out(port, UART_MTK_SAMPLE_POINT,
(tmp - 2) >> 1);
} else {
serial_port_out(port, UART_MTK_SAMPLE_COUNT, 0x00);
serial_port_out(port, UART_MTK_SAMPLE_POINT, 0xff);
}
spin_unlock_irqrestore(&port->lock, flags);
/* Don't rewrite B0 */
if (tty_termios_baud_rate(termios))
tty_termios_encode_baud_rate(termios, baud, baud);
}
static void
mtk8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
{
if (!state)
pm_runtime_get_sync(port->dev);
serial8250_do_pm(port, state, old);
if (state)
pm_runtime_put_sync_suspend(port->dev);
}
static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
struct mtk8250_data *data)
{
int err;
struct device_node *np = pdev->dev.of_node;
data->uart_clk = of_clk_get(np, 0);
if (IS_ERR(data->uart_clk)) {
dev_warn(&pdev->dev, "Can't get timer clock\n");
return PTR_ERR(data->uart_clk);
}
err = clk_prepare_enable(data->uart_clk);
if (err) {
dev_warn(&pdev->dev, "Can't prepare clock\n");
clk_put(data->uart_clk);
return err;
}
p->uartclk = clk_get_rate(data->uart_clk);
return 0;
}
static int mtk8250_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 mtk8250_data *data;
int err;
if (!regs || !irq) {
dev_err(&pdev->dev, "no registers/irq defined\n");
return -EINVAL;
}
uart.port.membase = devm_ioremap(&pdev->dev, regs->start,
resource_size(regs));
if (!uart.port.membase)
return -ENOMEM;
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
if (pdev->dev.of_node) {
err = mtk8250_probe_of(pdev, &uart.port, data);
if (err)
return err;
} else
return -ENODEV;
spin_lock_init(&uart.port.lock);
uart.port.mapbase = regs->start;
uart.port.irq = irq->start;
uart.port.pm = mtk8250_do_pm;
uart.port.type = PORT_16550;
uart.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT;
uart.port.dev = &pdev->dev;
uart.port.iotype = UPIO_MEM32;
uart.port.regshift = 2;
uart.port.private_data = data;
uart.port.set_termios = mtk8250_set_termios;
/* Disable Rate Fix function */
writel(0x0, uart.port.membase +
(MTK_UART_RATE_FIX << uart.port.regshift));
data->line = serial8250_register_8250_port(&uart);
if (data->line < 0)
return data->line;
platform_set_drvdata(pdev, data);
pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);
return 0;
}
static int mtk8250_remove(struct platform_device *pdev)
{
struct mtk8250_data *data = platform_get_drvdata(pdev);
pm_runtime_get_sync(&pdev->dev);
serial8250_unregister_port(data->line);
if (!IS_ERR(data->uart_clk)) {
clk_disable_unprepare(data->uart_clk);
clk_put(data->uart_clk);
}
pm_runtime_disable(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int mtk8250_suspend(struct device *dev)
{
struct mtk8250_data *data = dev_get_drvdata(dev);
serial8250_suspend_port(data->line);
return 0;
}
static int mtk8250_resume(struct device *dev)
{
struct mtk8250_data *data = dev_get_drvdata(dev);
serial8250_resume_port(data->line);
return 0;
}
#endif /* CONFIG_PM_SLEEP */
#ifdef CONFIG_PM
static int mtk8250_runtime_suspend(struct device *dev)
{
struct mtk8250_data *data = dev_get_drvdata(dev);
if (!IS_ERR(data->uart_clk))
clk_disable_unprepare(data->uart_clk);
return 0;
}
static int mtk8250_runtime_resume(struct device *dev)
{
struct mtk8250_data *data = dev_get_drvdata(dev);
if (!IS_ERR(data->uart_clk))
clk_prepare_enable(data->uart_clk);
return 0;
}
#endif
static const struct dev_pm_ops mtk8250_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(mtk8250_suspend, mtk8250_resume)
SET_RUNTIME_PM_OPS(mtk8250_runtime_suspend, mtk8250_runtime_resume,
NULL)
};
static const struct of_device_id mtk8250_of_match[] = {
{ .compatible = "mediatek,mt6577-uart" },
{ /* Sentinel */ }
};
MODULE_DEVICE_TABLE(of, mtk8250_of_match);
static struct platform_driver mtk8250_platform_driver = {
.driver = {
.name = "mt6577-uart",
.pm = &mtk8250_pm_ops,
.of_match_table = mtk8250_of_match,
},
.probe = mtk8250_probe,
.remove = mtk8250_remove,
};
module_platform_driver(mtk8250_platform_driver);
MODULE_AUTHOR("Matthias Brugger");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Mediatek 8250 serial port driver");