[PATCH v5 10/14] ARM: OMAP2+: gpmc: waitpin helper
Afzal Mohammed
afzal at ti.com
Mon Jun 11 10:27:21 EDT 2012
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 <afzal at ti.com>
---
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;
+ default:
+ dev_err(gpmc_dev, "multiple waitpins selected on CS:%u\n", cs);
+ return -EINVAL;
+ break;
+ }
+
+ 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;
+}
+
+static int gpmc_setup_waitpin(struct gpmc_peripheral *g_per)
+{
+ int ret;
+ u32 l, shift;
+
+ if (!g_per->have_waitpin)
+ return 0;
+
+ ret = gpmc_waitpin_request(g_per->waitpin);
+ if (IS_ERR_VALUE(ret)) {
+ dev_err(gpmc_dev, "waitpin %u reserved\n", g_per->waitpin);
+ return ret;
+ }
+
+ l = gpmc_read_reg(GPMC_CONFIG);
+ shift = g_per->waitpin + GPMC_CONFIG_WAITPIN_POLARITY_SHIFT;
+ if (g_per->waitpin_polarity == HIGH)
+ l |= 1 << shift;
+ else
+ l &= ~(1 << shift);
+ gpmc_write_reg(GPMC_CONFIG, l);
+
+ return 0;
+}
+
static __devinit int gpmc_probe(struct platform_device *pdev)
{
u32 l;
diff --git a/arch/arm/plat-omap/include/plat/gpmc.h b/arch/arm/plat-omap/include/plat/gpmc.h
index ff3f32c..e1b130c 100644
--- a/arch/arm/plat-omap/include/plat/gpmc.h
+++ b/arch/arm/plat-omap/include/plat/gpmc.h
@@ -64,6 +64,7 @@
#define GPMC_CONFIG1_WAIT_WRITE_MON (1 << 21)
#define GPMC_CONFIG1_WAIT_MON_IIME(val) ((val & 3) << 18)
#define GPMC_CONFIG1_WAIT_PIN_SEL(val) ((val & 3) << 16)
+#define GPMC_CONFIG1_WAIT_PIN_SEL_MASK GPMC_CONFIG1_WAIT_PIN_SEL(3)
#define GPMC_CONFIG1_DEVICESIZE(val) ((val & 3) << 12)
#define GPMC_CONFIG1_DEVICESIZE_8 GPMC_CONFIG1_DEVICESIZE(0)
#define GPMC_CONFIG1_DEVICESIZE_16 GPMC_CONFIG1_DEVICESIZE(1)
@@ -78,6 +79,14 @@
#define GPMC_CONFIG1_FCLK_DIV4 (GPMC_CONFIG1_FCLK_DIV(3))
#define GPMC_CONFIG7_CSVALID (1 << 6)
+#define GPMC_WAITPIN_ACTIVE_HIGH (1 << 4)
+#define GPMC_WAITPIN_ACTIVE_LOW (0 << 4)
+#define GPMC_WAITPIN_0 (1 << 0)
+#define GPMC_WAITPIN_1 (1 << 1)
+#define GPMC_WAITPIN_2 (1 << 2)
+#define GPMC_WAITPIN_3 (1 << 3)
+#define GPMC_WAITPIN_MASK (GPMC_WAITPIN_0 | GPMC_WAITPIN_1 | \
+ GPMC_WAITPIN_2 | GPMC_WAITPIN_3)
#define GPMC_DEVICETYPE_NOR 0
#define GPMC_DEVICETYPE_NAND 2
#define GPMC_CONFIG_WRITEPROTECT 0x00000010
--
1.7.10.2
More information about the linux-arm-kernel
mailing list