cpm2: Implement GPIO LIB API on CPM2 Freescale SoC.

This patch implement GPIO LIB support for the CPM2 GPIOs. The code can
also be used for CPM1 GPIO port E, as both cores are compatible at the
register level.

Based on earlier work by Laurent Pinchart.

Signed-off-by: Jochen Friedrich <jochen@scram.de>
Cc: Laurent Pinchart <laurentp@cse-semaphore.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

3 files changed, 136 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
index 1d0968775c0a..18a71839dc9e 100644
--- a/arch/powerpc/platforms/Kconfig
+++ b/arch/powerpc/platforms/Kconfig
@@ -254,6 +254,8 @@ config CPM2
 	select CPM
 	select PPC_LIB_RHEAP
 	select PPC_PCI_CHOICE
+	select ARCH_REQUIRE_GPIOLIB
+	select GENERIC_GPIO
 	help
 	  The CPM2 (Communications Processor Module) is a coprocessor on
 	  embedded CPUs made by Freescale.  Selecting this option means that
diff --git a/arch/powerpc/sysdev/cpm2.c b/arch/powerpc/sysdev/cpm2.c
index 5a6c5dfc53ef..9311778a5082 100644
--- a/arch/powerpc/sysdev/cpm2.c
+++ b/arch/powerpc/sysdev/cpm2.c
@@ -377,3 +377,14 @@ void cpm2_set_pin(int port, int pin, int flags)
 	else
 		clrbits32(&iop[port].odr, pin);
 }
+
+static int cpm_init_par_io(void)
+{
+	struct device_node *np;
+
+	for_each_compatible_node(np, NULL, "fsl,cpm2-pario-bank")
+		cpm2_gpiochip_add32(np);
+	return 0;
+}
+arch_initcall(cpm_init_par_io);
+
diff --git a/arch/powerpc/sysdev/cpm_common.c b/arch/powerpc/sysdev/cpm_common.c
index e4b7296acb2c..53da8a079f96 100644
--- a/arch/powerpc/sysdev/cpm_common.c
+++ b/arch/powerpc/sysdev/cpm_common.c
@@ -19,6 +19,8 @@
 
 #include <linux/init.h>
 #include <linux/of_device.h>
+#include <linux/spinlock.h>
+#include <linux/of.h>
 
 #include <asm/udbg.h>
 #include <asm/io.h>
@@ -28,6 +30,10 @@
 
 #include <mm/mmu_decl.h>
 
+#if defined(CONFIG_CPM2) || defined(CONFIG_8xx_GPIO)
+#include <linux/of_gpio.h>
+#endif
+
 #ifdef CONFIG_PPC_EARLY_DEBUG_CPM
 static u32 __iomem *cpm_udbg_txdesc =
 	(u32 __iomem __force *)CONFIG_PPC_EARLY_DEBUG_CPM_ADDR;
@@ -207,3 +213,120 @@ dma_addr_t cpm_muram_dma(void __iomem *addr)
 	return muram_pbase + ((u8 __iomem *)addr - muram_vbase);
 }
 EXPORT_SYMBOL(cpm_muram_dma);
+
+#if defined(CONFIG_CPM2) || defined(CONFIG_8xx_GPIO)
+
+struct cpm2_ioports {
+	u32 dir, par, sor, odr, dat;
+	u32 res[3];
+};
+
+struct cpm2_gpio32_chip {
+	struct of_mm_gpio_chip mm_gc;
+	spinlock_t lock;
+
+	/* shadowed data register to clear/set bits safely */
+	u32 cpdata;
+};
+
+static inline struct cpm2_gpio32_chip *
+to_cpm2_gpio32_chip(struct of_mm_gpio_chip *mm_gc)
+{
+	return container_of(mm_gc, struct cpm2_gpio32_chip, mm_gc);
+}
+
+static void cpm2_gpio32_save_regs(struct of_mm_gpio_chip *mm_gc)
+{
+	struct cpm2_gpio32_chip *cpm2_gc = to_cpm2_gpio32_chip(mm_gc);
+	struct cpm2_ioports __iomem *iop = mm_gc->regs;
+
+	cpm2_gc->cpdata = in_be32(&iop->dat);
+}
+
+static int cpm2_gpio32_get(struct gpio_chip *gc, unsigned int gpio)
+{
+	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+	struct cpm2_ioports __iomem *iop = mm_gc->regs;
+	u32 pin_mask;
+
+	pin_mask = 1 << (31 - gpio);
+
+	return !!(in_be32(&iop->dat) & pin_mask);
+}
+
+static void cpm2_gpio32_set(struct gpio_chip *gc, unsigned int gpio, int value)
+{
+	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+	struct cpm2_gpio32_chip *cpm2_gc = to_cpm2_gpio32_chip(mm_gc);
+	struct cpm2_ioports __iomem *iop = mm_gc->regs;
+	unsigned long flags;
+	u32 pin_mask = 1 << (31 - gpio);
+
+	spin_lock_irqsave(&cpm2_gc->lock, flags);
+
+	if (value)
+		cpm2_gc->cpdata |= pin_mask;
+	else
+		cpm2_gc->cpdata &= ~pin_mask;
+
+	out_be32(&iop->dat, cpm2_gc->cpdata);
+
+	spin_unlock_irqrestore(&cpm2_gc->lock, flags);
+}
+
+static int cpm2_gpio32_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+	struct cpm2_ioports __iomem *iop = mm_gc->regs;
+	u32 pin_mask;
+
+	pin_mask = 1 << (31 - gpio);
+
+	setbits32(&iop->dir, pin_mask);
+
+	cpm2_gpio32_set(gc, gpio, val);
+
+	return 0;
+}
+
+static int cpm2_gpio32_dir_in(struct gpio_chip *gc, unsigned int gpio)
+{
+	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+	struct cpm2_ioports __iomem *iop = mm_gc->regs;
+	u32 pin_mask;
+
+	pin_mask = 1 << (31 - gpio);
+
+	clrbits32(&iop->dir, pin_mask);
+
+	return 0;
+}
+
+int cpm2_gpiochip_add32(struct device_node *np)
+{
+	struct cpm2_gpio32_chip *cpm2_gc;
+	struct of_mm_gpio_chip *mm_gc;
+	struct of_gpio_chip *of_gc;
+	struct gpio_chip *gc;
+
+	cpm2_gc = kzalloc(sizeof(*cpm2_gc), GFP_KERNEL);
+	if (!cpm2_gc)
+		return -ENOMEM;
+
+	spin_lock_init(&cpm2_gc->lock);
+
+	mm_gc = &cpm2_gc->mm_gc;
+	of_gc = &mm_gc->of_gc;
+	gc = &of_gc->gc;
+
+	mm_gc->save_regs = cpm2_gpio32_save_regs;
+	of_gc->gpio_cells = 2;
+	gc->ngpio = 32;
+	gc->direction_input = cpm2_gpio32_dir_in;
+	gc->direction_output = cpm2_gpio32_dir_out;
+	gc->get = cpm2_gpio32_get;
+	gc->set = cpm2_gpio32_set;
+
+	return of_mm_gpiochip_add(np, mm_gc);
+}
+#endif /* CONFIG_CPM2 || CONFIG_8xx_GPIO */