[PATCH v4 2/4] mfd: lubbock_cplds: add lubbock IO board

Robert Jarzmik
2015-01-24T15:06:22Z

Lubbock () board is the IO motherboard of the Intel PXA25x Development
Platform, which supports the Lubbock pxa25x soc board.

Historically, this support was in arch/arm/mach-pxa/lubbock.c. When
gpio-pxa was moved to drivers/pxa, it became a driver, and its
initialization and probing happened at postcore initcall. The lubbock
code used to install the chained lubbock interrupt handler at init_irq()
time.

The consequence of the gpio-pxa change is that the installed chained irq
handler lubbock_irq_handler() was overwritten in pxa_gpio_probe(_dt)(),
removing :
- the handler
- the falling edge detection setting of GPIO0, which revealed the
interrupt request from the lubbock IO board.

As a fix, move the gpio0 chained handler setup to a place where we have
the guarantee that pxa_gpio_probe() was called before, so that lubbock
handler becomes the true IRQ chained handler of GPIO0, demuxing the
lubbock IO board interrupts.

This patch moves all that handling to a mfd driver. It's only purpose
for the time being is the interrupt handling, but in the future it
should encompass all the motherboard CPLDs handling :
- leds
- switches
- hexleds

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
---
Since v1: change the name from cottula to lubbock_io
Dmitry pointed out the Cottula was the pxa25x family name,
lubbock was the pxa25x development board name. Therefore the
name was changed to lubbock_io (lubbock IO board)
change the resources to bi-irq ioresource
Discussion between Arnd and Robert to change the gpio
request by a irq request.
Since v2: take into account Mark's review
Use irq flags from resources (DT case and pdata case).
Change of name from lubbock_io to lubbock-io
Since v3: take into account Lee's review + Russell's advice
whitespace errors fixes
debug/info messages formatting
return X; empty lines
---
drivers/mfd/Kconfig | 10 +++
drivers/mfd/Makefile | 1 +
drivers/mfd/lubbock.c | 199 ++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 210 insertions(+)
create mode 100644 drivers/mfd/lubbock.c

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 2e6b731..4d8939f 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -91,6 +91,16 @@ config MFD_AXP20X
components like regulators or the PEK (Power Enable Key) under the
corresponding menus.

+config MFD_LUBBOCK
+ bool "Lubbock Motherboard"
+ def_bool ARCH_LUBBOCK
+ select MFD_CORE
+ help
+ This driver supports the Lubbock multifunction chip found on the
+ pxa25x development platform system (named Lubbock). This IO board
+ supports the interrupts handling, ethernet controller, flash chips,
+ etc ...
+
config MFD_CROS_EC
tristate "ChromeOS Embedded Controller"
select MFD_CORE
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 53467e2..aff1f4f 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_MFD_88PM805) += 88pm805.o 88pm80x.o
obj-$(CONFIG_MFD_SM501) += sm501.o
obj-$(CONFIG_MFD_ASIC3) += asic3.o tmio_core.o
obj-$(CONFIG_MFD_BCM590XX) += bcm590xx.o
+obj-$(CONFIG_MFD_LUBBOCK) += lubbock.o
obj-$(CONFIG_MFD_CROS_EC) += cros_ec.o
obj-$(CONFIG_MFD_CROS_EC_I2C) += cros_ec_i2c.o
obj-$(CONFIG_MFD_CROS_EC_SPI) += cros_ec_spi.o
diff --git a/drivers/mfd/lubbock.c b/drivers/mfd/lubbock.c
new file mode 100644
index 0000000..4077fc5
--- /dev/null
+++ b/drivers/mfd/lubbock.c
@@ -0,0 +1,199 @@
+/*
+ * Intel Cotulla MFD - lubbock motherboard
+ *
+ * Copyright (C) 2014 Robert Jarzmik
+ *
+ * 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.
+ *
+ * Lubbock motherboard driver, supporting Lubbock (aka. PXA25X) SoC board.
+ */
+
+#include <linux/bitops.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+
+#define COT_IRQ_MASK_EN 0xc0
+#define COT_IRQ_SET_CLR 0xd0
+
+#define LUBBOCK_NB_IRQ 8
+
+struct lubbock {
+ void __iomem *base;
+ int irq;
+ unsigned int irq_mask;
+ struct gpio_desc *gpio0;
+ struct irq_domain *irqdomain;
+};
+
+static irqreturn_t lubbock_irq_handler(int in_irq, void *d)
+{
+ struct lubbock *cot = d;
+ unsigned long pending;
+ unsigned int bit;
+
+ pending = readl(cot->base + COT_IRQ_SET_CLR) & cot->irq_mask;
+ for_each_set_bit(bit, &pending, LUBBOCK_NB_IRQ)
+ generic_handle_irq(irq_find_mapping(cot->irqdomain, bit));
+
+ return IRQ_HANDLED;
+}
+
+static void lubbock_irq_mask_ack(struct irq_data *d)
+{
+ struct lubbock *cot = irq_data_get_irq_chip_data(d);
+ unsigned int lubbock_irq = irqd_to_hwirq(d);
+ unsigned int set, bit = BIT(lubbock_irq);
+
+ cot->irq_mask &= ~bit;
+ writel(cot->irq_mask, cot->base + COT_IRQ_MASK_EN);
+ set = readl(cot->base + COT_IRQ_SET_CLR);
+ writel(set & ~bit, cot->base + COT_IRQ_SET_CLR);
+}
+
+static void lubbock_irq_unmask(struct irq_data *d)
+{
+ struct lubbock *cot = irq_data_get_irq_chip_data(d);
+ unsigned int lubbock_irq = irqd_to_hwirq(d);
+ unsigned int bit = BIT(lubbock_irq);
+
+ cot->irq_mask |= bit;
+ writel(cot->irq_mask, cot->base + COT_IRQ_MASK_EN);
+}
+
+static struct irq_chip lubbock_irq_chip = {
+ .name = "lubbock",
+ .irq_mask_ack = lubbock_irq_mask_ack,
+ .irq_unmask = lubbock_irq_unmask,
+ .flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_SKIP_SET_WAKE,
+};
+
+static int lubbock_irq_domain_map(struct irq_domain *d, unsigned int irq,
+ irq_hw_number_t hwirq)
+{
+ struct lubbock *cot = d->host_data;
+
+ irq_set_chip_and_handler(irq, &lubbock_irq_chip, handle_level_irq);
+ irq_set_chip_data(irq, cot);
+
+ return 0;
+}
+
+static const struct irq_domain_ops lubbock_irq_domain_ops = {
+ .xlate = irq_domain_xlate_twocell,
+ .map = lubbock_irq_domain_map,
+};
+
+static int lubbock_resume(struct platform_device *pdev)
+{
+ struct lubbock *cot = platform_get_drvdata(pdev);
+
+ writel(cot->irq_mask, cot->base + COT_IRQ_MASK_EN);
+
+ return 0;
+}
+
+static int lubbock_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct lubbock *cot;
+ int ret;
+ unsigned int base_irq = 0;
+ unsigned long irqflags;
+
+ cot = devm_kzalloc(&pdev->dev, sizeof(*cot), GFP_KERNEL);
+ if (!cot)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ if (res) {
+ cot->irq = (unsigned int)res->start;
+ irqflags = res->flags;
+ }
+ if (!cot->irq)
+ return -ENODEV;
+
+ base_irq = platform_get_irq(pdev, 1);
+ if (base_irq < 0)
+ base_irq = 0;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ cot->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(cot->base))
+ return PTR_ERR(cot->base);
+
+ platform_set_drvdata(pdev, cot);
+
+ writel(cot->irq_mask, cot->base + COT_IRQ_MASK_EN);
+ writel(0, cot->base + COT_IRQ_SET_CLR);
+
+ ret = devm_request_irq(&pdev->dev, cot->irq, lubbock_irq_handler,
+ irqflags, dev_name(&pdev->dev), cot);
+ if (ret == -ENOSYS)
+ return -EPROBE_DEFER;
+
+ if (ret) {
+ dev_err(&pdev->dev, "couldn't request main irq%d: %d\n",
+ cot->irq, ret);
+ return ret;
+ }
+
+ irq_set_irq_wake(cot->irq, 1);
+ cot->irqdomain = irq_domain_add_linear(pdev->dev.of_node,
+ LUBBOCK_NB_IRQ,
+ &lubbock_irq_domain_ops, cot);
+ if (!cot->irqdomain)
+ return -ENODEV;
+
+ if (base_irq) {
+ ret = irq_create_strict_mappings(cot->irqdomain, base_irq, 0,
+ LUBBOCK_NB_IRQ);
+ if (ret) {
+ dev_err(&pdev->dev, "couldn't create the irq mapping %d..%d\n",
+ base_irq, base_irq + LUBBOCK_NB_IRQ);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static int lubbock_remove(struct platform_device *pdev)
+{
+ struct lubbock *cot = platform_get_drvdata(pdev);
+
+ irq_set_chip_and_handler(cot->irq, NULL, NULL);
+
+ return 0;
+}
+
+static const struct of_device_id lubbock_id_table[] = {
+ { .compatible = "intel,lubbock-cplds", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, lubbock_id_table);
+
+static struct platform_driver lubbock_driver = {
+ .driver = {
+ .name = "lubbock_cplds",
+ .of_match_table = of_match_ptr(lubbock_id_table),
+ },
+ .probe = lubbock_probe,
+ .remove = lubbock_remove,
+ .resume = lubbock_resume,
+};
+
+module_platform_driver(lubbock_driver);
+
+MODULE_DESCRIPTION("Lubbock MFD driver");
+MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
+MODULE_LICENSE("GPL");
--
2.1.0