lkml.org 
[lkml]   [2021]   [Nov]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] memory: renesas-rpc-if: avoid use of undocumented bits
Date
Instead of writing fixed values with undocumented bits which happen to
be set on some SoCs, better switch to read-modify-write operations
changing only bits which are documented. This is way more future-proof
as we don't know yet how these bits may be on upcoming SoCs.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---

This patch is based on the Krzysztof's for-next branch as it depends on
Prabhakar's G2L additions.

Tested on a V3U with some debug code verifying that the same values are
written before and after the patch.

@Prabhakar: would you be so kind and test this patch on G2L?

drivers/memory/renesas-rpc-if.c | 58 +++++++++++++--------------------
1 file changed, 22 insertions(+), 36 deletions(-)

diff --git a/drivers/memory/renesas-rpc-if.c b/drivers/memory/renesas-rpc-if.c
index 8c51145c0f5c..a9f3e7bdddf8 100644
--- a/drivers/memory/renesas-rpc-if.c
+++ b/drivers/memory/renesas-rpc-if.c
@@ -20,7 +20,6 @@

#define RPCIF_CMNCR 0x0000 /* R/W */
#define RPCIF_CMNCR_MD BIT(31)
-#define RPCIF_CMNCR_SFDE BIT(24) /* undocumented but must be set */
#define RPCIF_CMNCR_MOIIO3(val) (((val) & 0x3) << 22)
#define RPCIF_CMNCR_MOIIO2(val) (((val) & 0x3) << 20)
#define RPCIF_CMNCR_MOIIO1(val) (((val) & 0x3) << 18)
@@ -290,49 +289,36 @@ int rpcif_hw_init(struct rpcif *rpc, bool hyperflash)
rpcif_rzg2l_timing_adjust_sdr(rpc);
}

- /*
- * NOTE: The 0x260 are undocumented bits, but they must be set.
- * RPCIF_PHYCNT_STRTIM is strobe timing adjustment bits,
- * 0x0 : the delay is biggest,
- * 0x1 : the delay is 2nd biggest,
- * On H3 ES1.x, the value should be 0, while on others,
- * the value should be 7.
- */
- if (rpc->type == RPCIF_RCAR_GEN3) {
- regmap_write(rpc->regmap, RPCIF_PHYCNT, RPCIF_PHYCNT_STRTIM(7) |
- RPCIF_PHYCNT_PHYMEM(hyperflash ? 3 : 0) | 0x260);
- } else {
- regmap_read(rpc->regmap, RPCIF_PHYCNT, &dummy);
- dummy &= ~RPCIF_PHYCNT_PHYMEM_MASK;
- dummy |= RPCIF_PHYCNT_PHYMEM(hyperflash ? 3 : 0) | 0x260;
- regmap_write(rpc->regmap, RPCIF_PHYCNT, dummy);
- }
+ regmap_update_bits(rpc->regmap, RPCIF_PHYCNT, RPCIF_PHYCNT_PHYMEM_MASK,
+ RPCIF_PHYCNT_PHYMEM(hyperflash ? 3 : 0));
+
+ if (rpc->type == RPCIF_RCAR_GEN3)
+ regmap_update_bits(rpc->regmap, RPCIF_PHYCNT,
+ RPCIF_PHYCNT_STRTIM(7), RPCIF_PHYCNT_STRTIM(7));

- /*
- * NOTE: The 0x1511144 are undocumented bits, but they must be set
- * for RPCIF_PHYOFFSET1.
- * The 0x31 are undocumented bits, but they must be set
- * for RPCIF_PHYOFFSET2.
- */
- regmap_write(rpc->regmap, RPCIF_PHYOFFSET1, 0x1511144 |
- RPCIF_PHYOFFSET1_DDRTMG(3));
- regmap_write(rpc->regmap, RPCIF_PHYOFFSET2, 0x31 |
- RPCIF_PHYOFFSET2_OCTTMG(4));
+ regmap_update_bits(rpc->regmap, RPCIF_PHYOFFSET1, RPCIF_PHYOFFSET1_DDRTMG(3),
+ RPCIF_PHYOFFSET1_DDRTMG(3));
+ regmap_update_bits(rpc->regmap, RPCIF_PHYOFFSET2, RPCIF_PHYOFFSET2_OCTTMG(7),
+ RPCIF_PHYOFFSET2_OCTTMG(4));

if (hyperflash)
regmap_update_bits(rpc->regmap, RPCIF_PHYINT,
RPCIF_PHYINT_WPVAL, 0);

if (rpc->type == RPCIF_RCAR_GEN3)
- regmap_write(rpc->regmap, RPCIF_CMNCR, RPCIF_CMNCR_SFDE |
- RPCIF_CMNCR_MOIIO_HIZ | RPCIF_CMNCR_IOFV_HIZ |
- RPCIF_CMNCR_BSZ(hyperflash ? 1 : 0));
+ regmap_update_bits(rpc->regmap, RPCIF_CMNCR,
+ RPCIF_CMNCR_MOIIO_HIZ | RPCIF_CMNCR_BSZ(3),
+ RPCIF_CMNCR_MOIIO_HIZ |
+ RPCIF_CMNCR_BSZ(hyperflash ? 1 : 0));
else
- regmap_write(rpc->regmap, RPCIF_CMNCR, RPCIF_CMNCR_SFDE |
- RPCIF_CMNCR_MOIIO3(1) | RPCIF_CMNCR_MOIIO2(1) |
- RPCIF_CMNCR_MOIIO1(1) | RPCIF_CMNCR_MOIIO0(1) |
- RPCIF_CMNCR_IO3FV(2) | RPCIF_CMNCR_IO2FV(2) |
- RPCIF_CMNCR_IO0FV(2) | RPCIF_CMNCR_BSZ(hyperflash ? 1 : 0));
+ regmap_update_bits(rpc->regmap, RPCIF_CMNCR,
+ RPCIF_CMNCR_MOIIO_HIZ | RPCIF_CMNCR_IOFV_HIZ |
+ RPCIF_CMNCR_BSZ(3),
+ RPCIF_CMNCR_MOIIO3(1) | RPCIF_CMNCR_MOIIO2(1) |
+ RPCIF_CMNCR_MOIIO1(1) | RPCIF_CMNCR_MOIIO0(1) |
+ RPCIF_CMNCR_IO3FV(2) | RPCIF_CMNCR_IO2FV(2) |
+ RPCIF_CMNCR_IO0FV(2) |
+ RPCIF_CMNCR_BSZ(hyperflash ? 1 : 0));

/* Set RCF after BSZ update */
regmap_write(rpc->regmap, RPCIF_DRCR, RPCIF_DRCR_RCF);
--
2.30.2
\
 
 \ /
  Last update: 2021-11-17 10:38    [W:0.115 / U:0.132 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site