On 06/11/2012 09:27 AM, Afzal Mohammed wrote:
> Helper for configuring waitpin. There are two parts to it;
> configuring at CS level and the other at device level.
> A device embedding multiple CS has been provided the
> capability to use same waitpin (different waitpins has not
> been supported as presently there are no GPMC peripherals
> doing so)
>
> Signed-off-by: Afzal Mohammed <[email protected]>
> ---
> arch/arm/mach-omap2/gpmc.c | 122
> ++++++++++++++++++++++++++++++++
> arch/arm/plat-omap/include/plat/gpmc.h | 9 +++
> 2 files changed, 131 insertions(+)
>
> diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
> index 5a6f708..9073a8a 100644
> --- a/arch/arm/mach-omap2/gpmc.c
> +++ b/arch/arm/mach-omap2/gpmc.c
> @@ -75,6 +75,8 @@
> #define GPMC_CONFIG6_CYCLE2CYCLEDIFFCSEN BIT(6)
> #define GPMC_CONFIG6_CYCLE2CYCLESAMECSEN BIT(7)
>
> +#define GPMC_CONFIG_WAITPIN_POLARITY_SHIFT 0x8
> +
> #define GPMC_CS0_OFFSET 0x60
> #define GPMC_CS_SIZE 0x30
>
> @@ -93,6 +95,19 @@
> */
> #define GPMC_NR_IRQ 2
>
> +enum {
> + GPMC_WAITPIN_IDX0,
> + GPMC_WAITPIN_IDX1,
> + GPMC_WAITPIN_IDX2,
> + GPMC_WAITPIN_IDX3,
> + GPMC_NR_WAITPIN
> +};
> +
> +enum {
> + LOW,
> + HIGH
> +};
> +
> struct gpmc_client_irq {
> unsigned irq;
> u32 bitmask;
> @@ -140,6 +155,8 @@ struct gpmc_peripheral {
> struct platform_device *pdev;
> };
>
> +static unsigned gpmc_waitpin_map;
> +
> static struct gpmc_client_irq gpmc_client_irq[GPMC_NR_IRQ];
> static struct irq_chip gpmc_irq_chip;
> static unsigned gpmc_irq_start;
> @@ -1162,6 +1179,62 @@ static void gpmc_print_cs_timings(int cs)
> gpmc_get_one_timing(cs, GPMC_CS_CONFIG6, 7, 7));
> }
>
> +static int gpmc_setup_cs_waitpin(struct gpmc_peripheral *g_per, unsigned cs,
> + unsigned conf)
> +{
> + unsigned idx;
> + bool polarity = 0;
> + u32 l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG1);
> +
> + switch (conf & GPMC_WAITPIN_MASK) {
> + case GPMC_WAITPIN_0:
> + idx = GPMC_WAITPIN_IDX0;
> + break;
> + case GPMC_WAITPIN_1:
> + idx = GPMC_WAITPIN_IDX1;
> + break;
> + case GPMC_WAITPIN_2:
> + idx = GPMC_WAITPIN_IDX2;
> + break;
> + case GPMC_WAITPIN_3:
> + idx = GPMC_WAITPIN_IDX3;
> + break;
> + /* no waitpin */
> + case 0:
> + return 0;
> + break;
Do you need the break and return?
> + default:
> + dev_err(gpmc_dev, "multiple waitpins selected on CS:%u\n", cs);
> + return -EINVAL;
> + break;
Same as above.
> + }
> +
> + polarity = !!(conf & GPMC_WAITPIN_ACTIVE_HIGH);
> +
> + if (g_per->have_waitpin) {
> + if (g_per->waitpin != idx ||
> + g_per->waitpin_polarity != polarity) {
> + dev_err(gpmc_dev, "error: conflict: waitpin %u with
> polarity %d on device %s.%d\n",
> + g_per->waitpin, g_per->waitpin_polarity,
> + g_per->name, g_per->id);
> + return -EBUSY;
> + }
> + } else {
> + g_per->have_waitpin = true;
> + g_per->waitpin = idx;
> + g_per->waitpin_polarity = polarity;
> + }
> +
> + l |= conf & GPMC_CONFIG1_WAIT_WRITE_MON;
> + l |= conf & GPMC_CONFIG1_WAIT_READ_MON;
> + l &= ~GPMC_CONFIG1_WAIT_PIN_SEL_MASK;
> + l |= GPMC_CONFIG1_WAIT_PIN_SEL(idx);
> +
> + gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1, l);
> +
> + return 0;
> +}
> +
> static inline unsigned gpmc_bit_to_irq(unsigned bitmask)
> {
> return bitmask;
> @@ -1185,6 +1258,55 @@ static __devinit int gpmc_setup_cs_irq(struct
> gpmc_cs_data *cs,
> return n;
> }
>
> +static inline int gpmc_waitpin_is_reserved(unsigned waitpin)
> +{
> + return gpmc_waitpin_map & (0x1 << waitpin);
> +}
> +
> +static inline void gpmc_reserve_waitpin(unsigned waitpin)
> +{
> + gpmc_waitpin_map &= ~(0x1 << waitpin);
> + gpmc_waitpin_map |= (0x1 << waitpin);
> +}
> +
> +static int gpmc_waitpin_request(unsigned waitpin)
> +{
> + if (!(waitpin < GPMC_NR_WAITPIN))
> + return -ENODEV;
> +
> + if (gpmc_waitpin_is_reserved(waitpin))
> + return -EBUSY;
> + else
> + gpmc_reserve_waitpin(waitpin);
> +
> + return 0;
> +}
I am wondering if we should combine all the gpmc_xxx_request pin
functions into one. For example ...
static int gpmc_pin_request(int type, int pin)
{
int pin_num, pin_mask;
switch(type) {
case GPMC_PIN_TYPE_CS:
pin_num = GPMC_CS_NUM;
pin_mask = gpmc_cs_map;
break;
case GPMC_PIN_TYPE_WAIT:
pin_num = GPMC_NR_WAITPN;
pin_mask = gpmc_waitpin_map;
break;
case GPMC_PIN_TYPE_WRITEPROTECT:
pin_num = GPMC_NR_WP;
pin_mask = gpmc_wp_map;
break;
default:
return -ENODEV;
}
if (pin >= pin_num)
return -ENODEV;
if (gpmc_pin_is_reserved(pin_mask, pin))
return -EBUSY;
gpmc_reserve_pin(pin_mask, pin);
return 0;
}
Jon
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