On 02/20/2017 10:12 PM, Boris Brezillon wrote:
> 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 <[email protected]>
> ---
> 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;
You probably want to multiply before dividing to retain precision.
> + /*
> + * 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;
Ew, that's totally cryptic here ...
> + totalcycles += ncycles;
> + ret = atmel_smc_cs_conf_set_setup(smcconf, ATMEL_SMC_NWE_SHIFT,
> + ncycles);
> + if (ret)
> + return ret;
[...]
> +static const struct atmel_nand_controller_caps atmel_sam9260_nc_caps = {
> + .ale_offs = 1 << 21,
> + .cle_offs = 1 << 22,
BIT(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",
>
--
Best regards,
Marek Vasut
