linux/drivers/mfd/jz4740-adc.c

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/*
* Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
* JZ4740 SoC ADC driver
*
* 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.
*
* This driver synchronizes access to the JZ4740 ADC core between the
* JZ4740 battery and hwmon drivers.
*/
#include <linux/err.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/clk.h>
#include <linux/mfd/core.h>
#include <linux/jz4740-adc.h>
#define JZ_REG_ADC_ENABLE 0x00
#define JZ_REG_ADC_CFG 0x04
#define JZ_REG_ADC_CTRL 0x08
#define JZ_REG_ADC_STATUS 0x0c
#define JZ_REG_ADC_TOUCHSCREEN_BASE 0x10
#define JZ_REG_ADC_BATTERY_BASE 0x1c
#define JZ_REG_ADC_HWMON_BASE 0x20
#define JZ_ADC_ENABLE_TOUCH BIT(2)
#define JZ_ADC_ENABLE_BATTERY BIT(1)
#define JZ_ADC_ENABLE_ADCIN BIT(0)
enum {
JZ_ADC_IRQ_ADCIN = 0,
JZ_ADC_IRQ_BATTERY,
JZ_ADC_IRQ_TOUCH,
JZ_ADC_IRQ_PENUP,
JZ_ADC_IRQ_PENDOWN,
};
struct jz4740_adc {
struct resource *mem;
void __iomem *base;
int irq;
struct irq_chip_generic *gc;
struct clk *clk;
atomic_t clk_ref;
spinlock_t lock;
};
static void jz4740_adc_irq_demux(unsigned int irq, struct irq_desc *desc)
{
struct irq_chip_generic *gc = irq_desc_get_handler_data(desc);
uint8_t status;
unsigned int i;
status = readb(gc->reg_base + JZ_REG_ADC_STATUS);
for (i = 0; i < 5; ++i) {
if (status & BIT(i))
generic_handle_irq(gc->irq_base + i);
}
}
/* Refcounting for the ADC clock is done in here instead of in the clock
* framework, because it is the only clock which is shared between multiple
* devices and thus is the only clock which needs refcounting */
static inline void jz4740_adc_clk_enable(struct jz4740_adc *adc)
{
if (atomic_inc_return(&adc->clk_ref) == 1)
clk_prepare_enable(adc->clk);
}
static inline void jz4740_adc_clk_disable(struct jz4740_adc *adc)
{
if (atomic_dec_return(&adc->clk_ref) == 0)
clk_disable_unprepare(adc->clk);
}
static inline void jz4740_adc_set_enabled(struct jz4740_adc *adc, int engine,
bool enabled)
{
unsigned long flags;
uint8_t val;
spin_lock_irqsave(&adc->lock, flags);
val = readb(adc->base + JZ_REG_ADC_ENABLE);
if (enabled)
val |= BIT(engine);
else
val &= ~BIT(engine);
writeb(val, adc->base + JZ_REG_ADC_ENABLE);
spin_unlock_irqrestore(&adc->lock, flags);
}
static int jz4740_adc_cell_enable(struct platform_device *pdev)
{
struct jz4740_adc *adc = dev_get_drvdata(pdev->dev.parent);
jz4740_adc_clk_enable(adc);
jz4740_adc_set_enabled(adc, pdev->id, true);
return 0;
}
static int jz4740_adc_cell_disable(struct platform_device *pdev)
{
struct jz4740_adc *adc = dev_get_drvdata(pdev->dev.parent);
jz4740_adc_set_enabled(adc, pdev->id, false);
jz4740_adc_clk_disable(adc);
return 0;
}
int jz4740_adc_set_config(struct device *dev, uint32_t mask, uint32_t val)
{
struct jz4740_adc *adc = dev_get_drvdata(dev);
unsigned long flags;
uint32_t cfg;
if (!adc)
return -ENODEV;
spin_lock_irqsave(&adc->lock, flags);
cfg = readl(adc->base + JZ_REG_ADC_CFG);
cfg &= ~mask;
cfg |= val;
writel(cfg, adc->base + JZ_REG_ADC_CFG);
spin_unlock_irqrestore(&adc->lock, flags);
return 0;
}
EXPORT_SYMBOL_GPL(jz4740_adc_set_config);
static struct resource jz4740_hwmon_resources[] = {
{
.start = JZ_ADC_IRQ_ADCIN,
.flags = IORESOURCE_IRQ,
},
{
.start = JZ_REG_ADC_HWMON_BASE,
.end = JZ_REG_ADC_HWMON_BASE + 3,
.flags = IORESOURCE_MEM,
},
};
static struct resource jz4740_battery_resources[] = {
{
.start = JZ_ADC_IRQ_BATTERY,
.flags = IORESOURCE_IRQ,
},
{
.start = JZ_REG_ADC_BATTERY_BASE,
.end = JZ_REG_ADC_BATTERY_BASE + 3,
.flags = IORESOURCE_MEM,
},
};
static const struct mfd_cell jz4740_adc_cells[] = {
{
.id = 0,
.name = "jz4740-hwmon",
.num_resources = ARRAY_SIZE(jz4740_hwmon_resources),
.resources = jz4740_hwmon_resources,
.enable = jz4740_adc_cell_enable,
.disable = jz4740_adc_cell_disable,
},
{
.id = 1,
.name = "jz4740-battery",
.num_resources = ARRAY_SIZE(jz4740_battery_resources),
.resources = jz4740_battery_resources,
.enable = jz4740_adc_cell_enable,
.disable = jz4740_adc_cell_disable,
},
};
static int jz4740_adc_probe(struct platform_device *pdev)
{
struct irq_chip_generic *gc;
struct irq_chip_type *ct;
struct jz4740_adc *adc;
struct resource *mem_base;
int ret;
int irq_base;
adc = devm_kzalloc(&pdev->dev, sizeof(*adc), GFP_KERNEL);
if (!adc) {
dev_err(&pdev->dev, "Failed to allocate driver structure\n");
return -ENOMEM;
}
adc->irq = platform_get_irq(pdev, 0);
if (adc->irq < 0) {
ret = adc->irq;
dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
return ret;
}
irq_base = platform_get_irq(pdev, 1);
if (irq_base < 0) {
dev_err(&pdev->dev, "Failed to get irq base: %d\n", irq_base);
return irq_base;
}
mem_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!mem_base) {
dev_err(&pdev->dev, "Failed to get platform mmio resource\n");
return -ENOENT;
}
/* Only request the shared registers for the MFD driver */
adc->mem = request_mem_region(mem_base->start, JZ_REG_ADC_STATUS,
pdev->name);
if (!adc->mem) {
dev_err(&pdev->dev, "Failed to request mmio memory region\n");
return -EBUSY;
}
adc->base = ioremap_nocache(adc->mem->start, resource_size(adc->mem));
if (!adc->base) {
ret = -EBUSY;
dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
goto err_release_mem_region;
}
adc->clk = clk_get(&pdev->dev, "adc");
if (IS_ERR(adc->clk)) {
ret = PTR_ERR(adc->clk);
dev_err(&pdev->dev, "Failed to get clock: %d\n", ret);
goto err_iounmap;
}
spin_lock_init(&adc->lock);
atomic_set(&adc->clk_ref, 0);
platform_set_drvdata(pdev, adc);
gc = irq_alloc_generic_chip("INTC", 1, irq_base, adc->base,
handle_level_irq);
ct = gc->chip_types;
ct->regs.mask = JZ_REG_ADC_CTRL;
ct->regs.ack = JZ_REG_ADC_STATUS;
ct->chip.irq_mask = irq_gc_mask_set_bit;
ct->chip.irq_unmask = irq_gc_mask_clr_bit;
ct->chip.irq_ack = irq_gc_ack_set_bit;
irq_setup_generic_chip(gc, IRQ_MSK(5), 0, 0, IRQ_NOPROBE | IRQ_LEVEL);
adc->gc = gc;
irq_set_handler_data(adc->irq, gc);
irq_set_chained_handler(adc->irq, jz4740_adc_irq_demux);
writeb(0x00, adc->base + JZ_REG_ADC_ENABLE);
writeb(0xff, adc->base + JZ_REG_ADC_CTRL);
ret = mfd_add_devices(&pdev->dev, 0, jz4740_adc_cells,
ARRAY_SIZE(jz4740_adc_cells), mem_base,
irq_base, NULL);
if (ret < 0)
goto err_clk_put;
return 0;
err_clk_put:
clk_put(adc->clk);
err_iounmap:
iounmap(adc->base);
err_release_mem_region:
release_mem_region(adc->mem->start, resource_size(adc->mem));
return ret;
}
static int jz4740_adc_remove(struct platform_device *pdev)
{
struct jz4740_adc *adc = platform_get_drvdata(pdev);
mfd_remove_devices(&pdev->dev);
irq_remove_generic_chip(adc->gc, IRQ_MSK(5), IRQ_NOPROBE | IRQ_LEVEL, 0);
kfree(adc->gc);
irq_set_handler_data(adc->irq, NULL);
irq_set_chained_handler(adc->irq, NULL);
iounmap(adc->base);
release_mem_region(adc->mem->start, resource_size(adc->mem));
clk_put(adc->clk);
return 0;
}
static struct platform_driver jz4740_adc_driver = {
.probe = jz4740_adc_probe,
.remove = jz4740_adc_remove,
.driver = {
.name = "jz4740-adc",
.owner = THIS_MODULE,
},
};
module_platform_driver(jz4740_adc_driver);
MODULE_DESCRIPTION("JZ4740 SoC ADC driver");
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:jz4740-adc");