[PATCH v2 03/22] memory: omap-gpmc: Introduce GPMC to NAND interface

Roger Quadros rogerq at ti.com
Fri Aug 7 02:12:13 PDT 2015


The OMAP GPMC module has certain registers dedicated for NAND
access and some NAND bits mixed with other GPMC functionality.

For the NAND dedicated registers we have the struct gpmc_nand_regs.

The NAND driver needs to access NAND specific bits from the
following non-dedicated registers
1) FIFOEVENT and TERMCOUNT from GPMC_IRQENABLE and GPMC_IRQSTATUS
2) EMPTYWRITEBUFFERSTATUS from GPMC_STATUS

For accessing these bits we introduce the struct gpmc_nand_ops.

Rename the gpmc_update_nand_reg() API to gpmc_omap_get_nand_ops()
and make it return the gpmc_nand_ops along with updating the
gpmc_nand_regs. This API will be called by the OMAP NAND driver
to access the necessary bits in GPMC register space.

Signed-off-by: Roger Quadros <rogerq at ti.com>
---
 drivers/memory/omap-gpmc.c | 21 +++++++++++++++++++++
 include/linux/omap-gpmc.h  | 42 ++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 61 insertions(+), 2 deletions(-)

diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c
index 3a27a84..79d78ab 100644
--- a/drivers/memory/omap-gpmc.c
+++ b/drivers/memory/omap-gpmc.c
@@ -1099,6 +1099,27 @@ void gpmc_update_nand_reg(struct gpmc_nand_regs *reg, int cs)
 	}
 }
 
+static struct gpmc_nand_ops nand_ops;
+
+/**
+ * gpmc_omap_get_nand_ops - Get the GPMC NAND interface
+ * @regs: the GPMC NAND register map exclusive for NAND use.
+ * @cs: GPMC chip select number on which the NAND sits. The
+ *      register map returned will be specific to this chip select.
+ *
+ * Returns NULL on error e.g. invalid cs.
+ */
+struct gpmc_nand_ops *gpmc_omap_get_nand_ops(struct gpmc_nand_regs *reg, int cs)
+{
+	if (cs >= gpmc_cs_num)
+		return NULL;
+
+	gpmc_update_nand_reg(reg, cs);
+
+	return &nand_ops;
+}
+EXPORT_SYMBOL_GPL(gpmc_omap_get_nand_ops);
+
 int gpmc_get_client_irq(unsigned irq_config)
 {
 	int i;
diff --git a/include/linux/omap-gpmc.h b/include/linux/omap-gpmc.h
index 2dcef1c..a811c91 100644
--- a/include/linux/omap-gpmc.h
+++ b/include/linux/omap-gpmc.h
@@ -14,14 +14,52 @@
 #define GPMC_IRQ_FIFOEVENTENABLE	0x01
 #define GPMC_IRQ_COUNT_EVENT		0x02
 
+enum gpmc_nand_irq {
+	GPMC_NAND_IRQ_FIFOEVENT = 0,
+	GPMC_NAND_IRQ_TERMCOUNT,
+};
+
+/**
+ * gpmc_nand_ops - Interface between NAND and GPMC
+ * @nand_irq_enable: enable the requested GPMC NAND interrupt event.
+ * @nand_irq_disable: disable the requested GPMC NAND interrupt event.
+ * @nand_irq_clear: clears the GPMC NAND interrupt event status.
+ * @nand_irq_status: get the NAND interrupt event status.
+ * @nand_write_buffer_empty: get the NAND write buffer empty status.
+ */
+struct gpmc_nand_ops {
+	int (*nand_irq_enable)(enum gpmc_nand_irq irq);
+	int (*nand_irq_disable)(enum gpmc_nand_irq irq);
+	void (*nand_irq_clear)(enum gpmc_nand_irq irq);
+	u32 (*nand_irq_status)(void);
+	bool (*nand_writebuffer_empty)(void);
+};
+
+struct gpmc_nand_regs;
+
+#if IS_ENABLED(CONFIG_OMAP_GPMC)
+struct gpmc_nand_ops *gpmc_omap_get_nand_ops(struct gpmc_nand_regs *regs,
+					     int cs);
+#else
+static inline gpmc_nand_ops *gpmc_omap_get_nand_ops(struct gpmc_nand_regs *regs,
+						    int cs);
+{
+	return NULL;
+}
+#endif /* CONFIG_OMAP_GPMC */
+
+/*--------------------------------*/
+
+/* deprecated APIs */
+extern void gpmc_update_nand_reg(struct gpmc_nand_regs *reg, int cs);
+/*--------------------------------*/
+
 extern int gpmc_calc_timings(struct gpmc_timings *gpmc_t,
 			     struct gpmc_settings *gpmc_s,
 			     struct gpmc_device_timings *dev_t);
 
-struct gpmc_nand_regs;
 struct device_node;
 
-extern void gpmc_update_nand_reg(struct gpmc_nand_regs *reg, int cs);
 extern int gpmc_get_client_irq(unsigned irq_config);
 
 extern unsigned int gpmc_ticks_to_ns(unsigned int ticks);
-- 
2.1.4




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