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Subject[PATCH v3] MFD: Add JZ4740 ADC driver
Date
This patch adds a MFD driver for the JZ4740 ADC unit. The driver is used to
demultiplex IRQs and synchronize access to shared registers between the battery,
hwmon and (future) touchscreen driver.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Samuel Ortiz <sameo@linux.intel.com>

---
Changes since v2
- Use atmic_t for clock ref-counting.
- Add a comment why ref-counting is done in the driver and not in the clock
framework.
- Return more appropriate error codes when resources are missing.
- Return result of mfd_add_devices at the end of the drivers probe function.
---
drivers/mfd/Kconfig | 8 +
drivers/mfd/Makefile | 1 +
drivers/mfd/jz4740-adc.c | 384 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/jz4740-adc.h | 32 ++++
4 files changed, 425 insertions(+), 0 deletions(-)
create mode 100644 drivers/mfd/jz4740-adc.c
create mode 100644 include/linux/jz4740-adc.h
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 3f65dd0..2cde665 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -524,6 +524,14 @@ config MFD_JANZ_CMODIO
host many different types of MODULbus daughterboards, including
CAN and GPIO controllers.

+config MFD_JZ4740_ADC
+ tristate "Support for the JZ4740 SoC ADC core"
+ select MFD_CORE
+ depends on MACH_JZ4740
+ help
+ Say yes here if you want support for the ADC unit in the JZ4740 SoC.
+ This driver is necessary for jz4740-battery and jz4740-hwmon driver.
+
endif # MFD_SUPPORT

menu "Multimedia Capabilities Port drivers"
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 130c5f0..8a751dd 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -73,3 +73,4 @@ obj-$(CONFIG_PMIC_ADP5520) += adp5520.o
obj-$(CONFIG_LPC_SCH) += lpc_sch.o
obj-$(CONFIG_MFD_RDC321X) += rdc321x-southbridge.o
obj-$(CONFIG_MFD_JANZ_CMODIO) += janz-cmodio.o
+obj-$(CONFIG_MFD_JZ4740_ADC) += jz4740-adc.o
diff --git a/drivers/mfd/jz4740-adc.c b/drivers/mfd/jz4740-adc.c
new file mode 100644
index 0000000..7a844ae
--- /dev/null
+++ b/drivers/mfd/jz4740-adc.c
@@ -0,0 +1,384 @@
+/*
+ * 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/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;
+ int irq_base;
+
+ struct clk *clk;
+ atomic_t clk_ref;
+
+ spinlock_t lock;
+};
+
+static inline void jz4740_adc_irq_set_masked(struct jz4740_adc *adc, int irq,
+ bool masked)
+{
+ unsigned long flags;
+ uint8_t val;
+
+ irq -= adc->irq_base;
+
+ spin_lock_irqsave(&adc->lock, flags);
+
+ val = readb(adc->base + JZ_REG_ADC_CTRL);
+ if (masked)
+ val |= BIT(irq);
+ else
+ val &= ~BIT(irq);
+ writeb(val, adc->base + JZ_REG_ADC_CTRL);
+
+ spin_unlock_irqrestore(&adc->lock, flags);
+}
+
+static void jz4740_adc_irq_mask(unsigned int irq)
+{
+ struct jz4740_adc *adc = get_irq_chip_data(irq);
+ jz4740_adc_irq_set_masked(adc, irq, true);
+}
+
+static void jz4740_adc_irq_unmask(unsigned int irq)
+{
+ struct jz4740_adc *adc = get_irq_chip_data(irq);
+ jz4740_adc_irq_set_masked(adc, irq, false);
+}
+
+static void jz4740_adc_irq_ack(unsigned int irq)
+{
+ struct jz4740_adc *adc = get_irq_chip_data(irq);
+
+ irq -= adc->irq_base;
+ writeb(BIT(irq), adc->base + JZ_REG_ADC_STATUS);
+}
+
+static struct irq_chip jz4740_adc_irq_chip = {
+ .name = "jz4740-adc",
+ .mask = jz4740_adc_irq_mask,
+ .unmask = jz4740_adc_irq_unmask,
+ .ack = jz4740_adc_irq_ack,
+};
+
+static void jz4740_adc_irq_demux(unsigned int irq, struct irq_desc *desc)
+{
+ struct jz4740_adc *adc = get_irq_desc_data(desc);
+ uint8_t status;
+ unsigned int i;
+
+ status = readb(adc->base + JZ_REG_ADC_STATUS);
+
+ for (i = 0; i < 5; ++i) {
+ if (status & BIT(i))
+ generic_handle_irq(adc->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_enable(adc->clk);
+}
+
+static inline void jz4740_adc_clk_disable(struct jz4740_adc *adc)
+{
+ if (atomic_dec_return(&adc->clk_ref) == 0)
+ clk_disable(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,
+ },
+};
+
+const struct mfd_cell jz4740_adc_cells[] = {
+ {
+ .id = 0,
+ .name = "jz4740-hwmon",
+ .num_resources = ARRAY_SIZE(jz4740_hwmon_resources),
+ .resources = jz4740_hwmon_resources,
+ .platform_data = (void *)&jz4740_adc_cells[0],
+ .data_size = sizeof(struct mfd_cell),
+
+ .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,
+ .platform_data = (void *)&jz4740_adc_cells[1],
+ .data_size = sizeof(struct mfd_cell),
+
+ .enable = jz4740_adc_cell_enable,
+ .disable = jz4740_adc_cell_disable,
+ },
+};
+
+static int __devinit jz4740_adc_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct jz4740_adc *adc;
+ struct resource *mem_base;
+ int irq;
+
+ adc = kmalloc(sizeof(*adc), GFP_KERNEL);
+
+ 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);
+ goto err_free;
+ }
+
+ adc->irq_base = platform_get_irq(pdev, 1);
+ if (adc->irq_base < 0) {
+ ret = adc->irq_base;
+ dev_err(&pdev->dev, "Failed to get irq base: %d\n", ret);
+ goto err_free;
+ }
+
+ mem_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!mem_base) {
+ ret = -ENOENT;
+ dev_err(&pdev->dev, "Failed to get platform mmio resource\n");
+ goto err_free;
+ }
+
+ /* 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) {
+ ret = -EBUSY;
+ dev_err(&pdev->dev, "Failed to request mmio memory region\n");
+ goto err_free;
+ }
+
+ 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);
+
+ for (irq = adc->irq_base; irq < adc->irq_base + 5; ++irq) {
+ set_irq_chip_data(irq, adc);
+ set_irq_chip_and_handler(irq, &jz4740_adc_irq_chip,
+ handle_level_irq);
+ }
+
+ set_irq_data(adc->irq, adc);
+ set_irq_chained_handler(adc->irq, jz4740_adc_irq_demux);
+
+ writeb(0x00, adc->base + JZ_REG_ADC_ENABLE);
+ writeb(0xff, adc->base + JZ_REG_ADC_CTRL);
+
+ return mfd_add_devices(&pdev->dev, 0, jz4740_adc_cells,
+ ARRAY_SIZE(jz4740_adc_cells), mem_base, adc->irq_base);
+
+err_iounmap:
+ platform_set_drvdata(pdev, NULL);
+ iounmap(adc->base);
+err_release_mem_region:
+ release_mem_region(adc->mem->start, resource_size(adc->mem));
+err_free:
+ kfree(adc);
+
+ return ret;
+}
+
+static int __devexit jz4740_adc_remove(struct platform_device *pdev)
+{
+ struct jz4740_adc *adc = platform_get_drvdata(pdev);
+
+ mfd_remove_devices(&pdev->dev);
+
+ set_irq_data(adc->irq, NULL);
+ set_irq_chained_handler(adc->irq, NULL);
+
+ iounmap(adc->base);
+ release_mem_region(adc->mem->start, resource_size(adc->mem));
+
+ clk_put(adc->clk);
+
+ platform_set_drvdata(pdev, NULL);
+
+ kfree(adc);
+
+ return 0;
+}
+
+struct platform_driver jz4740_adc_driver = {
+ .probe = jz4740_adc_probe,
+ .remove = __devexit_p(jz4740_adc_remove),
+ .driver = {
+ .name = "jz4740-adc",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init jz4740_adc_init(void)
+{
+ return platform_driver_register(&jz4740_adc_driver);
+}
+module_init(jz4740_adc_init);
+
+static void __exit jz4740_adc_exit(void)
+{
+ platform_driver_unregister(&jz4740_adc_driver);
+}
+module_exit(jz4740_adc_exit);
+
+MODULE_DESCRIPTION("JZ4740 SoC ADC driver");
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:jz4740-adc");
diff --git a/include/linux/jz4740-adc.h b/include/linux/jz4740-adc.h
new file mode 100644
index 0000000..9053f95
--- /dev/null
+++ b/include/linux/jz4740-adc.h
@@ -0,0 +1,32 @@
+
+#ifndef __LINUX_JZ4740_ADC
+#define __LINUX_JZ4740_ADC
+
+#include <linux/device.h>
+
+/*
+ * jz4740_adc_set_config - Configure a JZ4740 adc device
+ * @dev: Pointer to a jz4740-adc device
+ * @mask: Mask for the config value to be set
+ * @val: Value to be set
+ *
+ * This function can be used by the JZ4740 ADC mfd cells to configure their
+ * options in the shared config register.
+*/
+int jz4740_adc_set_config(struct device *dev, uint32_t mask, uint32_t val);
+
+#define JZ_ADC_CONFIG_SPZZ BIT(31)
+#define JZ_ADC_CONFIG_EX_IN BIT(30)
+#define JZ_ADC_CONFIG_DNUM_MASK (0x7 << 16)
+#define JZ_ADC_CONFIG_DMA_ENABLE BIT(15)
+#define JZ_ADC_CONFIG_XYZ_MASK (0x2 << 13)
+#define JZ_ADC_CONFIG_SAMPLE_NUM_MASK (0x7 << 10)
+#define JZ_ADC_CONFIG_CLKDIV_MASK (0xf << 5)
+#define JZ_ADC_CONFIG_BAT_MB BIT(4)
+
+#define JZ_ADC_CONFIG_DNUM(dnum) ((dnum) << 16)
+#define JZ_ADC_CONFIG_XYZ_OFFSET(dnum) ((xyz) << 13)
+#define JZ_ADC_CONFIG_SAMPLE_NUM(x) ((x) << 10)
+#define JZ_ADC_CONFIG_CLKDIV(div) ((div) << 5)
+
+#endif
--
1.5.6.5


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