[PATCH 2/3] mtd: nand: atmel: Add ->setup_data_interface() hooks

From: Boris Brezillon
Date: Mon Feb 20 2017 - 12:16:50 EST

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The NAND controller IP can adapt the NAND controller timings dynamically.
Implement the ->setup_data_interface() hook to support this feature.

Note that it's not supported on at91rm9200 because this SoC has a
completely different SMC block, which is not supported yet.

Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
---
drivers/mtd/nand/atmel/nand-controller.c | 333 ++++++++++++++++++++++++++++++-
1 file changed, 328 insertions(+), 5 deletions(-)

diff --git a/drivers/mtd/nand/atmel/nand-controller.c b/drivers/mtd/nand/atmel/nand-controller.c
index 4207c0d37826..ae46ef711d67 100644
--- a/drivers/mtd/nand/atmel/nand-controller.c
+++ b/drivers/mtd/nand/atmel/nand-controller.c
@@ -57,6 +57,7 @@
#include <linux/interrupt.h>
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/atmel-matrix.h>
+#include <linux/mfd/syscon/atmel-smc.h>
#include <linux/module.h>
#include <linux/mtd/nand.h>
#include <linux/of_address.h>
@@ -147,6 +148,8 @@ struct atmel_nand_cs {
void __iomem *virt;
dma_addr_t dma;
} io;
+
+ struct atmel_smc_cs_conf smcconf;
};

struct atmel_nand {
@@ -190,6 +193,8 @@ struct atmel_nand_controller_ops {
void (*nand_init)(struct atmel_nand_controller *nc,
struct atmel_nand *nand);
int (*ecc_init)(struct atmel_nand *nand);
+ int (*setup_data_interface)(struct atmel_nand *nand, int csline,
+ const struct nand_data_interface *conf);
};

struct atmel_nand_controller_caps {
@@ -1144,6 +1149,293 @@ static int atmel_hsmc_nand_ecc_init(struct atmel_nand *nand)
return 0;
}

+static int atmel_smc_nand_prepare_smcconf(struct atmel_nand *nand,
+ const struct nand_data_interface *conf,
+ struct atmel_smc_cs_conf *smcconf)
+{
+ u32 ncycles, totalcycles, timeps, mckperiodps;
+ struct atmel_nand_controller *nc;
+ int ret;
+
+ nc = to_nand_controller(nand->base.controller);
+
+ /* DDR interface not supported. */
+ if (conf->type != NAND_SDR_IFACE)
+ return -ENOTSUPP;
+
+ /*
+ * tRC < 30ns implies EDO mode. This controller does not support this
+ * mode.
+ */
+ if (conf->timings.sdr.tRC_min < 30)
+ return -ENOTSUPP;
+
+ atmel_smc_cs_conf_init(smcconf);
+
+ mckperiodps = NSEC_PER_SEC / clk_get_rate(nc->mck);
+ mckperiodps *= 1000;
+
+ /*
+ * Set write pulse timing. This one is easy to extract:
+ *
+ * NWE_PULSE = tWP
+ */
+ ncycles = DIV_ROUND_UP(conf->timings.sdr.tWP_min, mckperiodps);
+ totalcycles = ncycles;
+ ret = atmel_smc_cs_conf_set_pulse(smcconf, ATMEL_SMC_NWE_SHIFT,
+ ncycles);
+ if (ret)
+ return ret;
+
+ /*
+ * The write setup timing depends on the operation done on the NAND.
+ * All operations goes through the same data bus, but the operation
+ * type depends on the address we are writing to (ALE/CLE address
+ * lines).
+ * Since we have no way to differentiate the different operations at
+ * the SMC level, we must consider the worst case (the biggest setup
+ * time among all operation types):
+ *
+ * NWE_SETUP = max(tCLS, tCS, tALS, tDS) - NWE_PULSE
+ */
+ timeps = max3(conf->timings.sdr.tCLS_min, conf->timings.sdr.tCS_min,
+ conf->timings.sdr.tALS_min);
+ timeps = max(timeps, conf->timings.sdr.tDS_min);
+ ncycles = DIV_ROUND_UP(timeps, mckperiodps);
+ ncycles = ncycles > totalcycles ? ncycles - totalcycles : 0;
+ totalcycles += ncycles;
+ ret = atmel_smc_cs_conf_set_setup(smcconf, ATMEL_SMC_NWE_SHIFT,
+ ncycles);
+ if (ret)
+ return ret;
+
+ /*
+ * As for the write setup timing, the write hold timing depends on the
+ * operation done on the NAND:
+ *
+ * NWE_HOLD = max(tCLH, tCH, tALH, tDH, tWH)
+ */
+ timeps = max3(conf->timings.sdr.tCLH_min, conf->timings.sdr.tCH_min,
+ conf->timings.sdr.tALH_min);
+ timeps = max3(timeps, conf->timings.sdr.tDH_min,
+ conf->timings.sdr.tWH_min);
+ ncycles = DIV_ROUND_UP(timeps, mckperiodps);
+ totalcycles += ncycles;
+
+ /*
+ * The write cycle timing is directly matching tWC, but is also
+ * dependent on the other timings on the setup and hold timings we
+ * calculated earlier, which gives:
+ *
+ * NWE_CYCLE = max(tWC, NWE_SETUP + NWE_PULSE + NWE_HOLD)
+ */
+ ncycles = DIV_ROUND_UP(conf->timings.sdr.tWC_min, mckperiodps);
+ ncycles = max(totalcycles, ncycles);
+ ret = atmel_smc_cs_conf_set_cycle(smcconf, ATMEL_SMC_NWE_SHIFT,
+ ncycles);
+ if (ret)
+ return ret;
+
+ /*
+ * We don't want the CS line to be toggled between each byte/word
+ * transfer to the NAND. The only way to guarantee that is to have the
+ * NCS_{WR,RD}_{SETUP,HOLD} timings set to 0, which in turn means:
+ *
+ * NCS_WR_PULSE = NWE_CYCLE
+ */
+ ret = atmel_smc_cs_conf_set_pulse(smcconf, ATMEL_SMC_NCS_WR_SHIFT,
+ ncycles);
+ if (ret)
+ return ret;
+
+ /*
+ * As for the write setup timing, the read hold timing depends on the
+ * operation done on the NAND:
+ *
+ * NRD_HOLD = max(tREH, tRHOH)
+ */
+ timeps = max(conf->timings.sdr.tREH_min, conf->timings.sdr.tRHOH_min);
+ ncycles = DIV_ROUND_UP(timeps, mckperiodps);
+ totalcycles = ncycles;
+
+ /*
+ * TDF = tRHZ - NRD_HOLD
+ */
+ ncycles = DIV_ROUND_UP(conf->timings.sdr.tRHZ_max, mckperiodps);
+ ncycles -= totalcycles;
+
+ /*
+ * In ONFI 4.0 specs, tRHZ has been increased to support EDO NANDs and
+ * we might end up with a config that does not fit in the TDF field.
+ * Just take the max value in this case and hope that the NAND is more
+ * tolerant than advertised.
+ */
+ if (ncycles > ATMEL_SMC_MODE_TDF_MAX)
+ ncycles = ATMEL_SMC_MODE_TDF_MAX;
+
+ smcconf->mode |= ATMEL_SMC_MODE_TDF(ncycles) |
+ ATMEL_SMC_MODE_TDFMODE_OPTIMIZED;
+
+ /*
+ * Read pulse timing directly matches tRP:
+ *
+ * NRD_PULSE = tRP
+ */
+ ncycles = DIV_ROUND_UP(conf->timings.sdr.tRP_min, mckperiodps);
+ totalcycles += ncycles;
+ ret = atmel_smc_cs_conf_set_pulse(smcconf, ATMEL_SMC_NRD_SHIFT,
+ ncycles);
+ if (ret)
+ return ret;
+
+ /*
+ * The write cycle timing is directly matching tWC, but is also
+ * dependent on the setup and hold timings we calculated earlier,
+ * which gives:
+ *
+ * NRD_CYCLE = max(tRC, NRD_PULSE + NRD_HOLD)
+ *
+ * NRD_SETUP is always 0.
+ */
+ ncycles = DIV_ROUND_UP(conf->timings.sdr.tRC_min, mckperiodps);
+ ncycles = max(totalcycles, ncycles);
+ ret = atmel_smc_cs_conf_set_cycle(smcconf, ATMEL_SMC_NRD_SHIFT,
+ ncycles);
+ if (ret)
+ return ret;
+
+ /*
+ * We don't want the CS line to be toggled between each byte/word
+ * transfer from the NAND. The only way to guarantee that is to have
+ * the NCS_{WR,RD}_{SETUP,HOLD} timings set to 0, which in turn means:
+ *
+ * NCS_RD_PULSE = NRD_CYCLE
+ */
+ ret = atmel_smc_cs_conf_set_pulse(smcconf, ATMEL_SMC_NCS_RD_SHIFT,
+ ncycles);
+ if (ret)
+ return ret;
+
+ /* Txxx timings are directly matching tXXX ones. */
+ ncycles = DIV_ROUND_UP(conf->timings.sdr.tCLR_min, mckperiodps);
+ ret = atmel_smc_cs_conf_set_timing(smcconf,
+ ATMEL_HSMC_TIMINGS_TCLR_SHIFT,
+ ncycles);
+ if (ret)
+ return ret;
+
+ ncycles = DIV_ROUND_UP(conf->timings.sdr.tADL_min, mckperiodps);
+ ret = atmel_smc_cs_conf_set_timing(smcconf,
+ ATMEL_HSMC_TIMINGS_TADL_SHIFT,
+ ncycles);
+ if (ret)
+ return ret;
+
+ ncycles = DIV_ROUND_UP(conf->timings.sdr.tAR_min, mckperiodps);
+ ret = atmel_smc_cs_conf_set_timing(smcconf,
+ ATMEL_HSMC_TIMINGS_TAR_SHIFT,
+ ncycles);
+ if (ret)
+ return ret;
+
+ ncycles = DIV_ROUND_UP(conf->timings.sdr.tRR_min, mckperiodps);
+ ret = atmel_smc_cs_conf_set_timing(smcconf,
+ ATMEL_HSMC_TIMINGS_TRR_SHIFT,
+ ncycles);
+ if (ret)
+ return ret;
+
+ ncycles = DIV_ROUND_UP(conf->timings.sdr.tWB_max, mckperiodps);
+ ret = atmel_smc_cs_conf_set_timing(smcconf,
+ ATMEL_HSMC_TIMINGS_TWB_SHIFT,
+ ncycles);
+ if (ret)
+ return ret;
+
+ /* Attach the CS line to the NFC logic. */
+ smcconf->timings |= ATMEL_HSMC_TIMINGS_NFSEL;
+
+ /* Set the appropriate data bus width. */
+ if (nand->base.options & NAND_BUSWIDTH_16)
+ smcconf->mode |= ATMEL_SMC_MODE_DBW_16;
+
+ /* Operate in NRD/NWE READ/WRITEMODE. */
+ smcconf->mode |= ATMEL_SMC_MODE_READMODE_NRD |
+ ATMEL_SMC_MODE_WRITEMODE_NWE;
+
+ return 0;
+}
+
+static int atmel_smc_nand_setup_data_interface(struct atmel_nand *nand,
+ int csline,
+ const struct nand_data_interface *conf)
+{
+ struct atmel_nand_controller *nc;
+ struct atmel_smc_cs_conf smcconf;
+ struct atmel_nand_cs *cs;
+ int ret;
+
+ nc = to_nand_controller(nand->base.controller);
+
+ ret = atmel_smc_nand_prepare_smcconf(nand, conf, &smcconf);
+ if (ret)
+ return ret;
+
+ if (csline == NAND_DATA_IFACE_CHECK_ONLY)
+ return 0;
+
+ cs = &nand->cs[csline];
+ cs->smcconf = smcconf;
+ atmel_smc_cs_conf_apply(nc->smc, cs->id, &cs->smcconf);
+
+ return 0;
+}
+
+static int atmel_hsmc_nand_setup_data_interface(struct atmel_nand *nand,
+ int csline,
+ const struct nand_data_interface *conf)
+{
+ struct atmel_nand_controller *nc;
+ struct atmel_smc_cs_conf smcconf;
+ struct atmel_nand_cs *cs;
+ int ret;
+
+ nc = to_nand_controller(nand->base.controller);
+
+ ret = atmel_smc_nand_prepare_smcconf(nand, conf, &smcconf);
+ if (ret)
+ return ret;
+
+ if (csline == NAND_DATA_IFACE_CHECK_ONLY)
+ return 0;
+
+ cs = &nand->cs[csline];
+ cs->smcconf = smcconf;
+
+ if (cs->rb.type == ATMEL_NAND_NATIVE_RB)
+ cs->smcconf.timings |= ATMEL_HSMC_TIMINGS_RBNSEL(cs->rb.id);
+
+ atmel_hsmc_cs_conf_apply(nc->smc, cs->id, &cs->smcconf);
+
+ return 0;
+}
+
+static int atmel_nand_setup_data_interface(struct mtd_info *mtd, int csline,
+ const struct nand_data_interface *conf)
+{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ struct atmel_nand *nand = to_atmel_nand(chip);
+ struct atmel_nand_controller *nc;
+
+ nc = to_nand_controller(nand->base.controller);
+
+ if (csline >= nand->numcs ||
+ (csline < 0 && csline != NAND_DATA_IFACE_CHECK_ONLY))
+ return -EINVAL;
+
+ return nc->caps->ops->setup_data_interface(nand, csline, conf);
+}
+
static void atmel_nand_init(struct atmel_nand_controller *nc,
struct atmel_nand *nand)
{
@@ -1161,6 +1453,9 @@ static void atmel_nand_init(struct atmel_nand_controller *nc,
chip->write_buf = atmel_nand_write_buf;
chip->select_chip = atmel_nand_select_chip;

+ if (nc->mck && nc->caps->ops->setup_data_interface)
+ chip->setup_data_interface = atmel_nand_setup_data_interface;
+
/* Some NANDs require a longer delay than the default one (20us). */
chip->chip_delay = 40;

@@ -1735,6 +2030,12 @@ static int atmel_nand_controller_init(struct atmel_nand_controller *nc,
if (nc->caps->legacy_of_bindings || !nc->dev->of_node)
return 0;

+ nc->mck = of_clk_get(dev->parent->of_node, 0);
+ if (IS_ERR(nc->mck)) {
+ dev_err(dev, "Failed to retrieve MCK clk\n");
+ return PTR_ERR(nc->mck);
+ }
+
np = of_parse_phandle(dev->parent->of_node, "atmel,smc", 0);
if (!np) {
dev_err(dev, "Missing or invalid atmel,smc property\n");
@@ -2045,6 +2346,7 @@ const struct atmel_nand_controller_ops atmel_hsmc_nc_ops = {
.remove = atmel_hsmc_nand_controller_remove,
.ecc_init = atmel_hsmc_nand_ecc_init,
.nand_init = atmel_hsmc_nand_init,
+ .setup_data_interface = atmel_hsmc_nand_setup_data_interface,
};

static const struct atmel_nand_controller_caps atmel_sama5_nc_caps = {
@@ -2099,7 +2401,14 @@ atmel_smc_nand_controller_remove(struct atmel_nand_controller *nc)
return 0;
}

-const struct atmel_nand_controller_ops atmel_smc_nc_ops = {
+/*
+ * The SMC reg layout of at91rm9200 is completely different which prevents us
+ * from re-using atmel_smc_nand_setup_data_interface() for the
+ * ->setup_data_interface() hook.
+ * At this point, there's no support for the at91rm9200 SMC IP, so we leave
+ * ->setup_data_interface() unassigned.
+ */
+const struct atmel_nand_controller_ops at91rm9200_nc_ops = {
.probe = atmel_smc_nand_controller_probe,
.remove = atmel_smc_nand_controller_remove,
.ecc_init = atmel_nand_ecc_init,
@@ -2109,6 +2418,20 @@ const struct atmel_nand_controller_ops atmel_smc_nc_ops = {
static const struct atmel_nand_controller_caps atmel_rm9200_nc_caps = {
.ale_offs = 1 << 21,
.cle_offs = 1 << 22,
+ .ops = &at91rm9200_nc_ops,
+};
+
+const struct atmel_nand_controller_ops atmel_smc_nc_ops = {
+ .probe = atmel_smc_nand_controller_probe,
+ .remove = atmel_smc_nand_controller_remove,
+ .ecc_init = atmel_nand_ecc_init,
+ .nand_init = atmel_smc_nand_init,
+ .setup_data_interface = atmel_smc_nand_setup_data_interface,
+};
+
+static const struct atmel_nand_controller_caps atmel_sam9260_nc_caps = {
+ .ale_offs = 1 << 21,
+ .cle_offs = 1 << 22,
.ops = &atmel_smc_nc_ops,
};

@@ -2129,14 +2452,14 @@ static const struct atmel_nand_controller_caps atmel_sam9g45_nc_caps = {
static const struct atmel_nand_controller_caps atmel_rm9200_nand_caps = {
.ale_offs = 1 << 21,
.cle_offs = 1 << 22,
- .ops = &atmel_smc_nc_ops,
+ .ops = &at91rm9200_nc_ops,
.legacy_of_bindings = true,
};

static const struct atmel_nand_controller_caps atmel_sam9261_nand_caps = {
.ale_offs = 1 << 22,
.cle_offs = 1 << 21,
- .ops = &atmel_smc_nc_ops,
+ .ops = &at91rm9200_nc_ops,
.legacy_of_bindings = true,
};

@@ -2144,7 +2467,7 @@ static const struct atmel_nand_controller_caps atmel_sam9g45_nand_caps = {
.has_dma = true,
.ale_offs = 1 << 21,
.cle_offs = 1 << 22,
- .ops = &atmel_smc_nc_ops,
+ .ops = &at91rm9200_nc_ops,
.legacy_of_bindings = true,
};

@@ -2155,7 +2478,7 @@ static const struct of_device_id atmel_nand_controller_of_ids[] = {
},
{
.compatible = "atmel,at91sam9260-nand-controller",
- .data = &atmel_rm9200_nc_caps,
+ .data = &atmel_sam9260_nc_caps,
},
{
.compatible = "atmel,at91sam9261-nand-controller",
--
2.7.4

Next message: Boris Brezillon: "[PATCH 0/3] mtd: nand: atmel: Add ->setup_data_interface() + PM ops"
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Next in thread: Boris Brezillon: "[PATCH 2/3] memory: atmel-ebi: Add missing ->numcs assignment"
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