Re: [PATCH 06/33] ARM: pxa/lubbock: add GPIO driver for LUB_MISC_WR register

[Russell King - ARM Linux]

On Mon, Aug 29, 2016 at 09:57:20PM +0200, Robert Jarzmik wrote:
> Russell King  writes:
> If gpio_reg_init() failed (and I know, the probability of a lack of memory at
> that stage of the kernel boot is ridiculous), this will end up as an NULL
> pointer dereference if either IRDA or PCMCIA is used.
> 
> If it's expected, then the the pr_err() below would deserve a pr_crit(). I 
> would
> as well take an option on a "panic()" if lubbock_misc_wr_gc allocation fails. 
> If
> not, maybe a not-NULL test on lubbock_misc_wr_gc is in order, even if that 
> would
> be "hidding under the carpet" and rather difficult to debug later.
> 
> Apart this detail point, it's good for me.

I'd prefer to kill the function entirely.  The PCMCIA user of it goes
later in the series, and all that's left are the three users in lubbock.c,
those being IrDA and ads7846.  I'd like to see pxaficp go the same way
as sa1100_ir - converting to using gpiolib gpiod* APIs to manage the
FIR mode select GPIO itself internally.

That leaves ads7846_cs(), and I'd be surprised if SPI didn't already of
wiring GPIOs up as chip selects.

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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[PATCH 06/33] ARM: pxa/lubbock: add GPIO driver for LUB_MISC_WR register

[Russell King]

Add a gpio driver for the lubbock miscellaneous write IO register so we
can take advantage of subsystems modelled around gpiolib, rather than
having to provide platform specific callbacks.

Signed-off-by: Russell King 
---
 arch/arm/mach-pxa/Kconfig   |  1 +
 arch/arm/mach-pxa/lubbock.c | 24 
 2 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/arch/arm/mach-pxa/Kconfig b/arch/arm/mach-pxa/Kconfig
index cd894d69e766..e7577803a911 100644
--- a/arch/arm/mach-pxa/Kconfig
+++ b/arch/arm/mach-pxa/Kconfig
@@ -29,6 +29,7 @@ config MACH_PXA3XX_DT
 
 config ARCH_LUBBOCK
bool "Intel DBPXA250 Development Platform (aka Lubbock)"
+   select GPIO_REG
select PXA25x
select SA
 
diff --git a/arch/arm/mach-pxa/lubbock.c b/arch/arm/mach-pxa/lubbock.c
index 7245f3359564..e974d1eb0f88 100644
--- a/arch/arm/mach-pxa/lubbock.c
+++ b/arch/arm/mach-pxa/lubbock.c
@@ -13,6 +13,7 @@
  */
 #include 
 #include 
+#include 
 #include 
 #include 
 #include 
@@ -110,20 +111,18 @@ static unsigned long lubbock_pin_config[] __initdata = {
 };
 
 #define LUB_HEXLED __LUB_REG(LUBBOCK_FPGA_PHYS + 0x010)
-#define LUB_MISC_WR__LUB_REG(LUBBOCK_FPGA_PHYS + 0x080)
 
 void lubbock_set_hexled(uint32_t value)
 {
LUB_HEXLED = value;
 }
 
+static struct gpio_chip *lubbock_misc_wr_gc;
+
 void lubbock_set_misc_wr(unsigned int mask, unsigned int set)
 {
-   unsigned long flags;
-
-   local_irq_save(flags);
-   LUB_MISC_WR = (LUB_MISC_WR & ~mask) | (set & mask);
-   local_irq_restore(flags);
+   unsigned long m = mask, v = set;
+   lubbock_misc_wr_gc->set_multiple(lubbock_misc_wr_gc, , );
 }
 EXPORT_SYMBOL(lubbock_set_misc_wr);
 
@@ -443,9 +442,9 @@ static void lubbock_irda_transceiver_mode(struct device 
*dev, int mode)
 
local_irq_save(flags);
if (mode & IR_SIRMODE) {
-   LUB_MISC_WR &= ~(1 << 4);
+   lubbock_set_misc_wr(BIT(4), 0);
} else if (mode & IR_FIRMODE) {
-   LUB_MISC_WR |= 1 << 4;
+   lubbock_set_misc_wr(BIT(4), BIT(4));
}
pxa2xx_transceiver_mode(dev, mode);
local_irq_restore(flags);
@@ -463,6 +462,15 @@ static void __init lubbock_init(void)
 
pxa2xx_mfp_config(ARRAY_AND_SIZE(lubbock_pin_config));
 
+   lubbock_misc_wr_gc = gpio_reg_init(NULL, (void *)_MISC_WR,
+  -1, 16, "lubbock", 0, LUB_MISC_WR,
+  NULL);
+   if (IS_ERR(lubbock_misc_wr_gc)) {
+   pr_err("Lubbock: unable to register lubbock GPIOs: %ld\n",
+  PTR_ERR(lubbock_misc_wr_gc));
+   lubbock_misc_wr_gc = NULL;
+   }
+
pxa_set_ffuart_info(NULL);
pxa_set_btuart_info(NULL);
pxa_set_stuart_info(NULL);
-- 
2.1.0


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