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Message-ID: <20241030104717.88688-6-bastien.curutchet@bootlin.com>
Date: Wed, 30 Oct 2024 11:47:17 +0100
From: Bastien Curutchet <bastien.curutchet@...tlin.com>
To: Santosh Shilimkar <ssantosh@...nel.org>,
Krzysztof Kozlowski <krzk@...nel.org>,
Miquel Raynal <miquel.raynal@...tlin.com>,
Richard Weinberger <richard@....at>,
Vignesh Raghavendra <vigneshr@...com>
Cc: linux-kernel@...r.kernel.org,
linux-mtd@...ts.infradead.org,
Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
Herve Codina <herve.codina@...tlin.com>,
Christopher Cordahi <christophercordahi@...ometrics.ca>,
Bastien Curutchet <bastien.curutchet@...tlin.com>
Subject: [PATCH 5/5] mtd: rawnand: davinci: Implement setup_interface() operation
The setup_interface() operation isn't implemented. It forces the driver
to use the ONFI mode 0, though it could use more optimal modes.
Implement the setup_interface() operation. It uses the
aemif_set_cs_timings() function from the AEMIF driver to update the
chip select timings. The calculation of the register's contents is
directly extracted from ยง20.3.2.3 of the DaVinci TRM [1]
These timings are previously set by the AEMIF driver itself from
device-tree properties. Therefore, IMHO, failing to update them in the
setup_interface() isn't critical, which is why 0 is returned even when
timings aren't updated.
MAX_TH_PS and MAX_TSU_PS are the worst case timings based on the
Keystone2 and DaVinci datasheets.
[1] : https://www.ti.com/lit/ug/spruh77c/spruh77c.pdf
Signed-off-by: Bastien Curutchet <bastien.curutchet@...tlin.com>
---
drivers/mtd/nand/raw/davinci_nand.c | 78 +++++++++++++++++++++++++++++
1 file changed, 78 insertions(+)
diff --git a/drivers/mtd/nand/raw/davinci_nand.c b/drivers/mtd/nand/raw/davinci_nand.c
index 11dc30c29957..76f0306dfe77 100644
--- a/drivers/mtd/nand/raw/davinci_nand.c
+++ b/drivers/mtd/nand/raw/davinci_nand.c
@@ -20,6 +20,7 @@
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
+#include <memory/ti-aemif.h>
#define NRCSR_OFFSET 0x00
#define NANDFCR_OFFSET 0x60
@@ -44,6 +45,9 @@
#define MASK_ALE 0x08
#define MASK_CLE 0x10
+#define MAX_TSU_PS 3000 /* Input setup time in ps */
+#define MAX_TH_PS 1600 /* Input hold time in ps */
+
struct davinci_nand_pdata {
uint32_t mask_ale;
uint32_t mask_cle;
@@ -120,6 +124,7 @@ struct davinci_nand_info {
uint32_t core_chipsel;
struct clk *clk;
+ struct aemif_device *aemif;
};
static DEFINE_SPINLOCK(davinci_nand_lock);
@@ -767,9 +772,81 @@ static int davinci_nand_exec_op(struct nand_chip *chip,
return 0;
}
+#define TO_CYCLES(ps, period_ns) (DIV_ROUND_UP((ps) / 1000, (period_ns)))
+
+static int davinci_nand_setup_interface(struct nand_chip *chip, int chipnr,
+ const struct nand_interface_config *conf)
+{
+ struct davinci_nand_info *info = to_davinci_nand(nand_to_mtd(chip));
+ const struct nand_sdr_timings *sdr;
+ struct aemif_cs_timings timings;
+ s32 cfg, min, cyc_ns;
+
+ cyc_ns = 1000000000 / clk_get_rate(info->clk);
+
+ sdr = nand_get_sdr_timings(conf);
+ if (IS_ERR(sdr))
+ return PTR_ERR(sdr);
+
+ cfg = TO_CYCLES(sdr->tCLR_min, cyc_ns) - 1;
+ timings.rsetup = cfg > 0 ? cfg : 0;
+
+ cfg = max_t(s32, TO_CYCLES(sdr->tREA_max + MAX_TSU_PS, cyc_ns),
+ TO_CYCLES(sdr->tRP_min, cyc_ns)) - 1;
+ timings.rstrobe = cfg > 0 ? cfg : 0;
+
+ min = TO_CYCLES(sdr->tCEA_max + MAX_TSU_PS, cyc_ns) - 2;
+ while ((s32)(timings.rsetup + timings.rstrobe) < min)
+ timings.rstrobe++;
+
+ cfg = TO_CYCLES((s32)(MAX_TH_PS - sdr->tCHZ_max), cyc_ns) - 1;
+ timings.rhold = cfg > 0 ? cfg : 0;
+
+ min = TO_CYCLES(sdr->tRC_min, cyc_ns) - 3;
+ while ((s32)(timings.rsetup + timings.rstrobe + timings.rhold) < min)
+ timings.rhold++;
+
+ cfg = TO_CYCLES((s32)(sdr->tRHZ_max - (timings.rhold + 1) * cyc_ns * 1000), cyc_ns);
+ cfg = max_t(s32, cfg, TO_CYCLES(sdr->tCHZ_max, cyc_ns)) - 1;
+ timings.ta = cfg > 0 ? cfg : 0;
+
+ cfg = TO_CYCLES(sdr->tWP_min, cyc_ns) - 1;
+ timings.wstrobe = cfg > 0 ? cfg : 0;
+
+ cfg = max_t(s32, TO_CYCLES(sdr->tCLS_min, cyc_ns), TO_CYCLES(sdr->tALS_min, cyc_ns));
+ cfg = max_t(s32, cfg, TO_CYCLES(sdr->tCS_min, cyc_ns)) - 1;
+ timings.wsetup = cfg > 0 ? cfg : 0;
+
+ min = TO_CYCLES(sdr->tDS_min, cyc_ns) - 2;
+ while ((s32)(timings.wsetup + timings.wstrobe) < min)
+ timings.wstrobe++;
+
+ cfg = max_t(s32, TO_CYCLES(sdr->tCLH_min, cyc_ns), TO_CYCLES(sdr->tALH_min, cyc_ns));
+ cfg = max_t(s32, cfg, TO_CYCLES(sdr->tCH_min, cyc_ns));
+ cfg = max_t(s32, cfg, TO_CYCLES(sdr->tDH_min, cyc_ns)) - 1;
+ timings.whold = cfg > 0 ? cfg : 0;
+
+ min = TO_CYCLES(sdr->tWC_min, cyc_ns) - 2;
+ while ((s32)(timings.wsetup + timings.wstrobe + timings.whold) < min)
+ timings.whold++;
+
+ dev_dbg(&info->pdev->dev, "RSETUP %x RSTROBE %x RHOLD %x\n",
+ timings.rsetup, timings.rstrobe, timings.rhold);
+ dev_dbg(&info->pdev->dev, "TA %x\n", timings.ta);
+ dev_dbg(&info->pdev->dev, "WSETUP %x WSTROBE %x WHOLD %x\n",
+ timings.wsetup, timings.wstrobe, timings.whold);
+
+ if (aemif_set_cs_timings(info->aemif, info->core_chipsel, &timings) < 0)
+ dev_info(&info->pdev->dev,
+ "Failed to dynamically update the CS timings, keep them unchanged");
+
+ return 0;
+}
+
static const struct nand_controller_ops davinci_nand_controller_ops = {
.attach_chip = davinci_nand_attach_chip,
.exec_op = davinci_nand_exec_op,
+ .setup_interface = davinci_nand_setup_interface,
};
static int nand_davinci_probe(struct platform_device *pdev)
@@ -834,6 +911,7 @@ static int nand_davinci_probe(struct platform_device *pdev)
info->pdev = pdev;
info->base = base;
info->vaddr = vaddr;
+ info->aemif = dev_get_drvdata(pdev->dev.parent);
mtd = nand_to_mtd(&info->chip);
mtd->dev.parent = &pdev->dev;
--
2.47.0
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