Commit 88e0abcd authored by Pawel Moll's avatar Pawel Moll

mfd: Versatile Express system registers driver

This is a platform driver for Versatile Express' "system
register" block. It's a random collection of registers providing
the following functionality:

- low level platform functions like board ID access; in order to
  use those, the driver must be initialized early, either statically
  or based on the DT

- config bus bridge via "system control" interface; as the response
  from the controller does not generate interrupt (yet), the status
  register is periodically polled using a timer

- pseudo GPIO lines providing MMC card status and Flash WP#
  signal control

- LED interface for a set of 8 LEDs on the motherboard, with
  "heartbeat", "mmc0" and "cpu0" to "cpu5" as default triggers
Signed-off-by: default avatarPawel Moll <pawel.moll@arm.com>
parent 3ecbf05b
ARM Versatile Express system registers
--------------------------------------
This is a system control registers block, providing multiple low level
platform functions like board detection and identification, software
interrupt generation, MMC and NOR Flash control etc.
Required node properties:
- compatible value : = "arm,vexpress,sysreg";
- reg : physical base address and the size of the registers window
- gpio-controller : specifies that the node is a GPIO controller
- #gpio-cells : size of the GPIO specifier, should be 2:
- first cell is the pseudo-GPIO line number:
0 - MMC CARDIN
1 - MMC WPROT
2 - NOR FLASH WPn
- second cell can take standard GPIO flags (currently ignored).
Example:
v2m_sysreg: sysreg@10000000 {
compatible = "arm,vexpress-sysreg";
reg = <0x10000000 0x1000>;
gpio-controller;
#gpio-cells = <2>;
};
This block also can also act a bridge to the platform's configuration
bus via "system control" interface, addressing devices with site number,
position in the board stack, config controller, function and device
numbers - see motherboard's TRM for more details.
The node describing a config device must refer to the sysreg node via
"arm,vexpress,config-bridge" phandle (can be also defined in the node's
parent) and relies on the board topology properties - see main vexpress
node documentation for more details. It must must also define the
following property:
- arm,vexpress-sysreg,func : must contain two cells:
- first cell defines function number (eg. 1 for clock generator,
2 for voltage regulators etc.)
- device number (eg. osc 0, osc 1 etc.)
Example:
mcc {
arm,vexpress,config-bridge = <&v2m_sysreg>;
osc@0 {
compatible = "arm,vexpress-osc";
arm,vexpress-sysreg,func = <1 0>;
};
};
...@@ -138,4 +138,4 @@ obj-$(CONFIG_MFD_RC5T583) += rc5t583.o rc5t583-irq.o ...@@ -138,4 +138,4 @@ obj-$(CONFIG_MFD_RC5T583) += rc5t583.o rc5t583-irq.o
obj-$(CONFIG_MFD_SEC_CORE) += sec-core.o sec-irq.o obj-$(CONFIG_MFD_SEC_CORE) += sec-core.o sec-irq.o
obj-$(CONFIG_MFD_SYSCON) += syscon.o obj-$(CONFIG_MFD_SYSCON) += syscon.o
obj-$(CONFIG_MFD_LM3533) += lm3533-core.o lm3533-ctrlbank.o obj-$(CONFIG_MFD_LM3533) += lm3533-core.o lm3533-ctrlbank.o
obj-$(CONFIG_VEXPRESS_CONFIG) += vexpress-config.o obj-$(CONFIG_VEXPRESS_CONFIG) += vexpress-config.o vexpress-sysreg.o
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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.
*
* Copyright (C) 2012 ARM Limited
*/
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/io.h>
#include <linux/leds.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/timer.h>
#include <linux/vexpress.h>
#define SYS_ID 0x000
#define SYS_SW 0x004
#define SYS_LED 0x008
#define SYS_100HZ 0x024
#define SYS_FLAGS 0x030
#define SYS_FLAGSSET 0x030
#define SYS_FLAGSCLR 0x034
#define SYS_NVFLAGS 0x038
#define SYS_NVFLAGSSET 0x038
#define SYS_NVFLAGSCLR 0x03c
#define SYS_MCI 0x048
#define SYS_FLASH 0x04c
#define SYS_CFGSW 0x058
#define SYS_24MHZ 0x05c
#define SYS_MISC 0x060
#define SYS_DMA 0x064
#define SYS_PROCID0 0x084
#define SYS_PROCID1 0x088
#define SYS_CFGDATA 0x0a0
#define SYS_CFGCTRL 0x0a4
#define SYS_CFGSTAT 0x0a8
#define SYS_HBI_MASK 0xfff
#define SYS_ID_HBI_SHIFT 16
#define SYS_PROCIDx_HBI_SHIFT 0
#define SYS_MCI_CARDIN (1 << 0)
#define SYS_MCI_WPROT (1 << 1)
#define SYS_FLASH_WPn (1 << 0)
#define SYS_MISC_MASTERSITE (1 << 14)
#define SYS_CFGCTRL_START (1 << 31)
#define SYS_CFGCTRL_WRITE (1 << 30)
#define SYS_CFGCTRL_DCC(n) (((n) & 0xf) << 26)
#define SYS_CFGCTRL_FUNC(n) (((n) & 0x3f) << 20)
#define SYS_CFGCTRL_SITE(n) (((n) & 0x3) << 16)
#define SYS_CFGCTRL_POSITION(n) (((n) & 0xf) << 12)
#define SYS_CFGCTRL_DEVICE(n) (((n) & 0xfff) << 0)
#define SYS_CFGSTAT_ERR (1 << 1)
#define SYS_CFGSTAT_COMPLETE (1 << 0)
static void __iomem *vexpress_sysreg_base;
static struct device *vexpress_sysreg_dev;
static int vexpress_master_site;
void vexpress_flags_set(u32 data)
{
writel(~0, vexpress_sysreg_base + SYS_FLAGSCLR);
writel(data, vexpress_sysreg_base + SYS_FLAGSSET);
}
u32 vexpress_get_procid(int site)
{
if (site == VEXPRESS_SITE_MASTER)
site = vexpress_master_site;
return readl(vexpress_sysreg_base + (site == VEXPRESS_SITE_DB1 ?
SYS_PROCID0 : SYS_PROCID1));
}
u32 vexpress_get_hbi(int site)
{
u32 id;
switch (site) {
case VEXPRESS_SITE_MB:
id = readl(vexpress_sysreg_base + SYS_ID);
return (id >> SYS_ID_HBI_SHIFT) & SYS_HBI_MASK;
case VEXPRESS_SITE_MASTER:
case VEXPRESS_SITE_DB1:
case VEXPRESS_SITE_DB2:
id = vexpress_get_procid(site);
return (id >> SYS_PROCIDx_HBI_SHIFT) & SYS_HBI_MASK;
}
return ~0;
}
void __iomem *vexpress_get_24mhz_clock_base(void)
{
return vexpress_sysreg_base + SYS_24MHZ;
}
static void vexpress_sysreg_find_prop(struct device_node *node,
const char *name, u32 *val)
{
of_node_get(node);
while (node) {
if (of_property_read_u32(node, name, val) == 0) {
of_node_put(node);
return;
}
node = of_get_next_parent(node);
}
}
unsigned __vexpress_get_site(struct device *dev, struct device_node *node)
{
u32 site = 0;
WARN_ON(dev && node && dev->of_node != node);
if (dev && !node)
node = dev->of_node;
if (node) {
vexpress_sysreg_find_prop(node, "arm,vexpress,site", &site);
} else if (dev && dev->bus == &platform_bus_type) {
struct platform_device *pdev = to_platform_device(dev);
if (pdev->num_resources == 1 &&
pdev->resource[0].flags == IORESOURCE_BUS)
site = pdev->resource[0].start;
} else if (dev && strncmp(dev_name(dev), "ct:", 3) == 0) {
site = VEXPRESS_SITE_MASTER;
}
if (site == VEXPRESS_SITE_MASTER)
site = vexpress_master_site;
return site;
}
struct vexpress_sysreg_config_func {
u32 template;
u32 device;
};
static struct vexpress_config_bridge *vexpress_sysreg_config_bridge;
static struct timer_list vexpress_sysreg_config_timer;
static u32 *vexpress_sysreg_config_data;
static int vexpress_sysreg_config_tries;
static void *vexpress_sysreg_config_func_get(struct device *dev,
struct device_node *node)
{
struct vexpress_sysreg_config_func *config_func;
u32 site;
u32 position = 0;
u32 dcc = 0;
u32 func_device[2];
int err = -EFAULT;
if (node) {
of_node_get(node);
vexpress_sysreg_find_prop(node, "arm,vexpress,site", &site);
vexpress_sysreg_find_prop(node, "arm,vexpress,position",
&position);
vexpress_sysreg_find_prop(node, "arm,vexpress,dcc", &dcc);
err = of_property_read_u32_array(node,
"arm,vexpress-sysreg,func", func_device,
ARRAY_SIZE(func_device));
of_node_put(node);
} else if (dev && dev->bus == &platform_bus_type) {
struct platform_device *pdev = to_platform_device(dev);
if (pdev->num_resources == 1 &&
pdev->resource[0].flags == IORESOURCE_BUS) {
site = pdev->resource[0].start;
func_device[0] = pdev->resource[0].end;
func_device[1] = pdev->id;
err = 0;
}
}
if (err)
return NULL;
config_func = kzalloc(sizeof(*config_func), GFP_KERNEL);
if (!config_func)
return NULL;
config_func->template = SYS_CFGCTRL_DCC(dcc);
config_func->template |= SYS_CFGCTRL_FUNC(func_device[0]);
config_func->template |= SYS_CFGCTRL_SITE(site == VEXPRESS_SITE_MASTER ?
vexpress_master_site : site);
config_func->template |= SYS_CFGCTRL_POSITION(position);
config_func->device |= func_device[1];
dev_dbg(vexpress_sysreg_dev, "func 0x%p = 0x%x, %d\n", config_func,
config_func->template, config_func->device);
return config_func;
}
static void vexpress_sysreg_config_func_put(void *func)
{
kfree(func);
}
static int vexpress_sysreg_config_func_exec(void *func, int offset,
bool write, u32 *data)
{
int status;
struct vexpress_sysreg_config_func *config_func = func;
u32 command;
if (WARN_ON(!vexpress_sysreg_base))
return -ENOENT;
command = readl(vexpress_sysreg_base + SYS_CFGCTRL);
if (WARN_ON(command & SYS_CFGCTRL_START))
return -EBUSY;
command = SYS_CFGCTRL_START;
command |= write ? SYS_CFGCTRL_WRITE : 0;
command |= config_func->template;
command |= SYS_CFGCTRL_DEVICE(config_func->device + offset);
/* Use a canary for reads */
if (!write)
*data = 0xdeadbeef;
dev_dbg(vexpress_sysreg_dev, "command %x, data %x\n",
command, *data);
writel(*data, vexpress_sysreg_base + SYS_CFGDATA);
writel(0, vexpress_sysreg_base + SYS_CFGSTAT);
writel(command, vexpress_sysreg_base + SYS_CFGCTRL);
mb();
if (vexpress_sysreg_dev) {
/* Schedule completion check */
if (!write)
vexpress_sysreg_config_data = data;
vexpress_sysreg_config_tries = 100;
mod_timer(&vexpress_sysreg_config_timer,
jiffies + usecs_to_jiffies(100));
status = VEXPRESS_CONFIG_STATUS_WAIT;
} else {
/* Early execution, no timer available, have to spin */
u32 cfgstat;
do {
cpu_relax();
cfgstat = readl(vexpress_sysreg_base + SYS_CFGSTAT);
} while (!cfgstat);
if (!write && (cfgstat & SYS_CFGSTAT_COMPLETE))
*data = readl(vexpress_sysreg_base + SYS_CFGDATA);
status = VEXPRESS_CONFIG_STATUS_DONE;
if (cfgstat & SYS_CFGSTAT_ERR)
status = -EINVAL;
}
return status;
}
struct vexpress_config_bridge_info vexpress_sysreg_config_bridge_info = {
.name = "vexpress-sysreg",
.func_get = vexpress_sysreg_config_func_get,
.func_put = vexpress_sysreg_config_func_put,
.func_exec = vexpress_sysreg_config_func_exec,
};
static void vexpress_sysreg_config_complete(unsigned long data)
{
int status = VEXPRESS_CONFIG_STATUS_DONE;
u32 cfgstat = readl(vexpress_sysreg_base + SYS_CFGSTAT);
if (cfgstat & SYS_CFGSTAT_ERR)
status = -EINVAL;
if (!vexpress_sysreg_config_tries--)
status = -ETIMEDOUT;
if (status < 0) {
dev_err(vexpress_sysreg_dev, "error %d\n", status);
} else if (!(cfgstat & SYS_CFGSTAT_COMPLETE)) {
mod_timer(&vexpress_sysreg_config_timer,
jiffies + usecs_to_jiffies(50));
return;
}
if (vexpress_sysreg_config_data) {
*vexpress_sysreg_config_data = readl(vexpress_sysreg_base +
SYS_CFGDATA);
dev_dbg(vexpress_sysreg_dev, "read data %x\n",
*vexpress_sysreg_config_data);
vexpress_sysreg_config_data = NULL;
}
vexpress_config_complete(vexpress_sysreg_config_bridge, status);
}
void __init vexpress_sysreg_early_init(void __iomem *base)
{
struct device_node *node = of_find_compatible_node(NULL, NULL,
"arm,vexpress-sysreg");
if (node)
base = of_iomap(node, 0);
if (WARN_ON(!base))
return;
vexpress_sysreg_base = base;
if (readl(vexpress_sysreg_base + SYS_MISC) & SYS_MISC_MASTERSITE)
vexpress_master_site = VEXPRESS_SITE_DB2;
else
vexpress_master_site = VEXPRESS_SITE_DB1;
vexpress_sysreg_config_bridge = vexpress_config_bridge_register(
node, &vexpress_sysreg_config_bridge_info);
WARN_ON(!vexpress_sysreg_config_bridge);
}
void __init vexpress_sysreg_of_early_init(void)
{
vexpress_sysreg_early_init(NULL);
}
static struct vexpress_sysreg_gpio {
unsigned long reg;
u32 value;
} vexpress_sysreg_gpios[] = {
[VEXPRESS_GPIO_MMC_CARDIN] = {
.reg = SYS_MCI,
.value = SYS_MCI_CARDIN,
},
[VEXPRESS_GPIO_MMC_WPROT] = {
.reg = SYS_MCI,
.value = SYS_MCI_WPROT,
},
[VEXPRESS_GPIO_FLASH_WPn] = {
.reg = SYS_FLASH,
.value = SYS_FLASH_WPn,
},
};
static int vexpress_sysreg_gpio_direction_input(struct gpio_chip *chip,
unsigned offset)
{
return 0;
}
static int vexpress_sysreg_gpio_direction_output(struct gpio_chip *chip,
unsigned offset, int value)
{
return 0;
}
static int vexpress_sysreg_gpio_get(struct gpio_chip *chip,
unsigned offset)
{
struct vexpress_sysreg_gpio *gpio = &vexpress_sysreg_gpios[offset];
u32 reg_value = readl(vexpress_sysreg_base + gpio->reg);
return !!(reg_value & gpio->value);
}
static void vexpress_sysreg_gpio_set(struct gpio_chip *chip,
unsigned offset, int value)
{
struct vexpress_sysreg_gpio *gpio = &vexpress_sysreg_gpios[offset];
u32 reg_value = readl(vexpress_sysreg_base + gpio->reg);
if (value)
reg_value |= gpio->value;
else
reg_value &= ~gpio->value;
writel(reg_value, vexpress_sysreg_base + gpio->reg);
}
static struct gpio_chip vexpress_sysreg_gpio_chip = {
.label = "vexpress-sysreg",
.direction_input = vexpress_sysreg_gpio_direction_input,
.direction_output = vexpress_sysreg_gpio_direction_output,
.get = vexpress_sysreg_gpio_get,
.set = vexpress_sysreg_gpio_set,
.ngpio = ARRAY_SIZE(vexpress_sysreg_gpios),
.base = 0,
};
static ssize_t vexpress_sysreg_sys_id_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "0x%08x\n", readl(vexpress_sysreg_base + SYS_ID));
}
DEVICE_ATTR(sys_id, S_IRUGO, vexpress_sysreg_sys_id_show, NULL);
static int __devinit vexpress_sysreg_probe(struct platform_device *pdev)
{
int err;
struct resource *res = platform_get_resource(pdev,
IORESOURCE_MEM, 0);
if (!devm_request_mem_region(&pdev->dev, res->start,
resource_size(res), pdev->name)) {
dev_err(&pdev->dev, "Failed to request memory region!\n");
return -EBUSY;
}
if (!vexpress_sysreg_base)
vexpress_sysreg_base = devm_ioremap(&pdev->dev, res->start,
resource_size(res));
if (!vexpress_sysreg_base) {
dev_err(&pdev->dev, "Failed to obtain base address!\n");
return -EFAULT;
}
setup_timer(&vexpress_sysreg_config_timer,
vexpress_sysreg_config_complete, 0);
vexpress_sysreg_gpio_chip.dev = &pdev->dev;
err = gpiochip_add(&vexpress_sysreg_gpio_chip);
if (err) {
vexpress_config_bridge_unregister(
vexpress_sysreg_config_bridge);
dev_err(&pdev->dev, "Failed to register GPIO chip! (%d)\n",
err);
return err;
}
vexpress_sysreg_dev = &pdev->dev;
device_create_file(vexpress_sysreg_dev, &dev_attr_sys_id);
return 0;
}
static const struct of_device_id vexpress_sysreg_match[] = {
{ .compatible = "arm,vexpress-sysreg", },
{},
};
static struct platform_driver vexpress_sysreg_driver = {
.driver = {
.name = "vexpress-sysreg",
.of_match_table = vexpress_sysreg_match,
},
.probe = vexpress_sysreg_probe,
};
static int __init vexpress_sysreg_init(void)
{
return platform_driver_register(&vexpress_sysreg_driver);
}
core_initcall(vexpress_sysreg_init);
#if defined(CONFIG_LEDS_CLASS)
struct vexpress_sysreg_led {
u32 mask;
struct led_classdev cdev;
} vexpress_sysreg_leds[] = {
{ .mask = 1 << 0, .cdev.name = "v2m:green:user1",
.cdev.default_trigger = "heartbeat", },
{ .mask = 1 << 1, .cdev.name = "v2m:green:user2",
.cdev.default_trigger = "mmc0", },
{ .mask = 1 << 2, .cdev.name = "v2m:green:user3",
.cdev.default_trigger = "cpu0", },
{ .mask = 1 << 3, .cdev.name = "v2m:green:user4",
.cdev.default_trigger = "cpu1", },
{ .mask = 1 << 4, .cdev.name = "v2m:green:user5",
.cdev.default_trigger = "cpu2", },
{ .mask = 1 << 5, .cdev.name = "v2m:green:user6",
.cdev.default_trigger = "cpu3", },
{ .mask = 1 << 6, .cdev.name = "v2m:green:user7",
.cdev.default_trigger = "cpu4", },
{ .mask = 1 << 7, .cdev.name = "v2m:green:user8",
.cdev.default_trigger = "cpu5", },
};
static DEFINE_SPINLOCK(vexpress_sysreg_leds_lock);
static void vexpress_sysreg_led_brightness_set(struct led_classdev *cdev,
enum led_brightness brightness)
{
struct vexpress_sysreg_led *led = container_of(cdev,
struct vexpress_sysreg_led, cdev);
unsigned long flags;
u32 val;
spin_lock_irqsave(&vexpress_sysreg_leds_lock, flags);
val = readl(vexpress_sysreg_base + SYS_LED);
if (brightness == LED_OFF)
val &= ~led->mask;
else
val |= led->mask;
writel(val, vexpress_sysreg_base + SYS_LED);
spin_unlock_irqrestore(&vexpress_sysreg_leds_lock, flags);
}
static int __init vexpress_sysreg_init_leds(void)
{
struct vexpress_sysreg_led *led;
int i;
/* Clear all user LEDs */
writel(0, vexpress_sysreg_base + SYS_LED);
for (i = 0, led = vexpress_sysreg_leds;
i < ARRAY_SIZE(vexpress_sysreg_leds); i++, led++) {
int err;
led->cdev.brightness_set = vexpress_sysreg_led_brightness_set;
err = led_classdev_register(vexpress_sysreg_dev, &led->cdev);
if (err) {
dev_err(vexpress_sysreg_dev,
"Failed to register LED %d! (%d)\n",
i, err);
while (led--, i--)
led_classdev_unregister(&led->cdev);
return err;
}
}
return 0;
}
device_initcall(vexpress_sysreg_init_leds);
#endif
...@@ -24,6 +24,17 @@ ...@@ -24,6 +24,17 @@
#define VEXPRESS_CONFIG_STATUS_DONE 0 #define VEXPRESS_CONFIG_STATUS_DONE 0
#define VEXPRESS_CONFIG_STATUS_WAIT 1 #define VEXPRESS_CONFIG_STATUS_WAIT 1
#define VEXPRESS_GPIO_MMC_CARDIN 0
#define VEXPRESS_GPIO_MMC_WPROT 1
#define VEXPRESS_GPIO_FLASH_WPn 2
#define VEXPRESS_RES_FUNC(_site, _func) \
{ \
.start = (_site), \
.end = (_func), \
.flags = IORESOURCE_BUS, \
}
/* Config bridge API */ /* Config bridge API */
/** /**
...@@ -82,4 +93,18 @@ int vexpress_config_read(struct vexpress_config_func *func, int offset, ...@@ -82,4 +93,18 @@ int vexpress_config_read(struct vexpress_config_func *func, int offset,
int vexpress_config_write(struct vexpress_config_func *func, int offset, int vexpress_config_write(struct vexpress_config_func *func, int offset,
u32 data); u32 data);
/* Platform control */
u32 vexpress_get_procid(int site);
u32 vexpress_get_hbi(int site);
void *vexpress_get_24mhz_clock_base(void);
void vexpress_flags_set(u32 data);
#define vexpress_get_site_by_node(node) __vexpress_get_site(NULL, node)
#define vexpress_get_site_by_dev(dev) __vexpress_get_site(dev, NULL)
unsigned __vexpress_get_site(struct device *dev, struct device_node *node);
void vexpress_sysreg_early_init(void __iomem *base);
void vexpress_sysreg_of_early_init(void);
#endif #endif
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