[PATCH 2/7] mtd: nand: Introduce nand_data_interface

On Tue, 6 Sep 2016 15:34:44 +0200
Sascha Hauer [off-list ref] wrote:

On Tue, Sep 06, 2016 at 01:21:18PM +0200, Boris Brezillon wrote:

quoted

On Tue,  6 Sep 2016 12:39:10 +0200
Sascha Hauer [off-list ref] wrote:
  

quoted

Currently we have no data structure to fully describe a NAND timing.
We only have struct nand_sdr_timings for NAND timings in SDR mode,
but nothing for DDR mode and also no container to store both types
of timing.
This patch adds struct nand_data_interface which stores the timing
type and a union of different timings. This can be used to pass to
drivers in order to configure the timing.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 include/linux/mtd/nand.h | 109 ++++++++++++++++++++++++++---------------------
 1 file changed, 60 insertions(+), 49 deletions(-)

diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 9af9575..19c73ef 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h

@@ -568,6 +568,66 @@ struct nand_buffers {
 	uint8_t *databuf;
 };
 
+/*
+ * struct nand_sdr_timings - SDR NAND chip timings
+ *
+ * This struct defines the timing requirements of a SDR NAND chip.
+ * These information can be found in every NAND datasheets and the timings
+ * meaning are described in the ONFI specifications:
+ * www.onfi.org/~/media/ONFI/specs/onfi_3_1_spec.pdf (chapter 4.15 Timing
+ * Parameters)
+ *
+ * All these timings are expressed in picoseconds.
+ */
+
+struct nand_sdr_timings {
+	u32 tALH_min;
+	u32 tADL_min;
+	u32 tALS_min;
+	u32 tAR_min;
+	u32 tCEA_max;
+	u32 tCEH_min;
+	u32 tCH_min;
+	u32 tCHZ_max;
+	u32 tCLH_min;
+	u32 tCLR_min;
+	u32 tCLS_min;
+	u32 tCOH_min;
+	u32 tCS_min;
+	u32 tDH_min;
+	u32 tDS_min;
+	u32 tFEAT_max;
+	u32 tIR_min;
+	u32 tITC_max;
+	u32 tRC_min;
+	u32 tREA_max;
+	u32 tREH_min;
+	u32 tRHOH_min;
+	u32 tRHW_min;
+	u32 tRHZ_max;
+	u32 tRLOH_min;
+	u32 tRP_min;
+	u32 tRR_min;
+	u64 tRST_max;
+	u32 tWB_max;
+	u32 tWC_min;
+	u32 tWH_min;
+	u32 tWHR_min;
+	u32 tWP_min;
+	u32 tWW_min;
+};
+
+enum nand_data_interface_type {
+	NAND_SDR_IFACE,
+};
+  

I know this is my code, and I'm the one to blame here, but can you
document the nand_data_interface fields (kerneldoc format)?  

Sure, can do. Do you know what tCEH is? This one is not documented in
the ONFI spec.

Maybe you're not looking at the latest ONFI spec ;). Anyway, I was not
asking you to document the nand_sdr_timings fields (pointing to the
spec should be enough), just the nand_data_interface ones.