Add a proof of concept to support nand speed mode. This reduce load time about 4 times for large binary

Signed-off-by: Michael Trimarchi michael@amarulasolutions.com --- arch/arm/include/asm/mach-imx/regs-gpmi.h | 9 + drivers/mtd/nand/raw/mxs_nand.c | 238 ++++++++++++++++++++-- drivers/mtd/nand/raw/mxs_nand_dt.c | 9 +- include/mxs_nand.h | 1 + 4 files changed, 242 insertions(+), 15 deletions(-)

diff --git a/arch/arm/include/asm/mach-imx/regs-gpmi.h b/arch/arm/include/asm/mach-imx/regs-gpmi.h index 33daa53c45..7a15778631 100644 --- a/arch/arm/include/asm/mach-imx/regs-gpmi.h +++ b/arch/arm/include/asm/mach-imx/regs-gpmi.h @@ -93,6 +93,11 @@ struct mxs_gpmi_regs { #define GPMI_CTRL1_DECOUPLE_CS (1 << 24) #define GPMI_CTRL1_WRN_DLY_SEL_MASK (0x3 << 22) #define GPMI_CTRL1_WRN_DLY_SEL_OFFSET 22 +#define GPMI_CTRL1_WRN_DLY_SEL_4_TO_8NS 0x0 +#define GPMI_CTRL1_WRN_DLY_SEL_6_TO_10NS 0x1 +#define GPMI_CTRL1_WRN_DLY_SEL_7_TO_12NS 0x2 +#define GPMI_CTRL1_WRN_DLY_SEL_NO_DELAY 0x3 + #define GPMI_CTRL1_TIMEOUT_IRQ_EN (1 << 20) #define GPMI_CTRL1_GANGED_RDYBUSY (1 << 19) #define GPMI_CTRL1_BCH_MODE (1 << 18) @@ -111,6 +116,10 @@ struct mxs_gpmi_regs { #define GPMI_CTRL1_ATA_IRQRDY_POLARITY (1 << 2) #define GPMI_CTRL1_CAMERA_MODE (1 << 1) #define GPMI_CTRL1_GPMI_MODE (1 << 0) +#define GPMI_CTRL1_CLEAR_MASK (GPMI_CTRL1_WRN_DLY_SEL_MASK | \ + GPMI_CTRL1_DLL_ENABLE | \ + GPMI_CTRL1_RDN_DELAY_MASK | \ + GPMI_CTRL1_HALF_PERIOD)

#define GPMI_TIMING0_ADDRESS_SETUP_MASK (0xff << 16) #define GPMI_TIMING0_ADDRESS_SETUP_OFFSET 16 diff --git a/drivers/mtd/nand/raw/mxs_nand.c b/drivers/mtd/nand/raw/mxs_nand.c index e56ebcfddc..ba1ce9cf4c 100644 --- a/drivers/mtd/nand/raw/mxs_nand.c +++ b/drivers/mtd/nand/raw/mxs_nand.c @@ -26,8 +26,11 @@ #include <asm/arch/imx-regs.h> #include <asm/mach-imx/regs-bch.h> #include <asm/mach-imx/regs-gpmi.h> +#include <asm/arch/crm_regs.h> #include <asm/arch/sys_proto.h> #include <mxs_nand.h> +#include <linux/math64.h> +#include <clk.h>

#define MXS_NAND_DMA_DESCRIPTOR_COUNT 4

@@ -46,6 +49,10 @@ #endif

#define MXS_NAND_BCH_TIMEOUT 10000 +#define USEC_PER_SEC 1000000 +#define NSEC_PER_SEC 1000000000L + +#define TO_CYCLES(duration, period) DIV_ROUND_UP_ULL(duration, period)

struct nand_ecclayout fake_ecc_layout;

@@ -1310,6 +1317,206 @@ err1: return ret; }

+#if (defined(CONFIG_MX6UL) || defined(CONFIG_MX6ULL)) +/* + * <1> Firstly, we should know what's the GPMI-clock means. + * The GPMI-clock is the internal clock in the gpmi nand controller. + * If you set 100MHz to gpmi nand controller, the GPMI-clock's period + * is 10ns. Mark the GPMI-clock's period as GPMI-clock-period. + * + * <2> Secondly, we should know what's the frequency on the nand chip pins. + * The frequency on the nand chip pins is derived from the GPMI-clock. + * We can get it from the following equation: + * + * F = G / (DS + DH) + * + * F : the frequency on the nand chip pins. + * G : the GPMI clock, such as 100MHz. + * DS : GPMI_HW_GPMI_TIMING0:DATA_SETUP + * DH : GPMI_HW_GPMI_TIMING0:DATA_HOLD + * + * <3> Thirdly, when the frequency on the nand chip pins is above 33MHz, + * the nand EDO(extended Data Out) timing could be applied. + * The GPMI implements a feedback read strobe to sample the read data. + * The feedback read strobe can be delayed to support the nand EDO timing + * where the read strobe may deasserts before the read data is valid, and + * read data is valid for some time after read strobe. + * + * The following figure illustrates some aspects of a NAND Flash read: + * + * |<---tREA---->| + * | | + * | | | + * |<--tRP-->| | + * | | | + * __ ___|__________________________________ + * RDN ________/ | + * | + * /---------\ + * Read Data --------------< >--------- + * ---------/ + * | | + * |<-D->| + * FeedbackRDN ________ ____________ + * ___________/ + * + * D stands for delay, set in the HW_GPMI_CTRL1:RDN_DELAY. + * + * + * <4> Now, we begin to describe how to compute the right RDN_DELAY. + * + * 4.1) From the aspect of the nand chip pins: + * Delay = (tREA + C - tRP) {1} + * + * tREA : the maximum read access time. + * C : a constant to adjust the delay. default is 4000ps. + * tRP : the read pulse width, which is exactly: + * tRP = (GPMI-clock-period) * DATA_SETUP + * + * 4.2) From the aspect of the GPMI nand controller: + * Delay = RDN_DELAY * 0.125 * RP {2} + * + * RP : the DLL reference period. + * if (GPMI-clock-period > DLL_THRETHOLD) + * RP = GPMI-clock-period / 2; + * else + * RP = GPMI-clock-period; + * + * Set the HW_GPMI_CTRL1:HALF_PERIOD if GPMI-clock-period + * is greater DLL_THRETHOLD. In other SOCs, the DLL_THRETHOLD + * is 16000ps, but in mx6q, we use 12000ps. + * + * 4.3) since {1} equals {2}, we get: + * + * (tREA + 4000 - tRP) * 8 + * RDN_DELAY = ----------------------- {3} + * RP + */ +static void mxs_compute_timings(struct nand_chip *chip, + const struct nand_sdr_timings *sdr) +{ + struct mxs_nand_info *nand_info = nand_get_controller_data(chip); + unsigned long int clk_rate; + unsigned int dll_wait_time_us; + unsigned int dll_threshold_ps = nand_info->max_chain_delay; + unsigned int period_ps, reference_period_ps; + unsigned int data_setup_cycles, data_hold_cycles, addr_setup_cycles; + unsigned int tRP_ps; + bool use_half_period; + int sample_delay_ps, sample_delay_factor; + u16 busy_timeout_cycles; + u8 wrn_dly_sel; + u32 timing0; + u32 timing1; + u32 ctrl1n; + u32 clkcfg; + + if (sdr->tRC_min >= 30000) { + /* ONFI non-EDO modes [0-3] */ + clk_rate = 22000000; + wrn_dly_sel = GPMI_CTRL1_WRN_DLY_SEL_4_TO_8NS; + clkcfg = (3 << MXC_CCM_CSCDR1_BCH_PODF_OFFSET) | \ + (3 << MXC_CCM_CSCDR1_GPMI_PODF_OFFSET); + } else if (sdr->tRC_min >= 25000) { + /* ONFI EDO mode 4 */ + clk_rate = 80000000; + wrn_dly_sel = GPMI_CTRL1_WRN_DLY_SEL_NO_DELAY; + clkcfg = (1 << MXC_CCM_CSCDR1_BCH_PODF_OFFSET) | \ + (1 << MXC_CCM_CSCDR1_GPMI_PODF_OFFSET); + } else { + /* ONFI EDO mode 5 */ + clk_rate = 100000000; + wrn_dly_sel = GPMI_CTRL1_WRN_DLY_SEL_NO_DELAY; + clkcfg = (1 << MXC_CCM_CSCDR1_BCH_PODF_OFFSET) | \ + (1 << MXC_CCM_CSCDR1_GPMI_PODF_OFFSET); + } + + /* SDR core timings are given in picoseconds */ + period_ps = div_u64((u64)NSEC_PER_SEC * 1000, clk_rate); + + addr_setup_cycles = TO_CYCLES(sdr->tALS_min, period_ps); + data_setup_cycles = TO_CYCLES(sdr->tDS_min, period_ps); + data_hold_cycles = TO_CYCLES(sdr->tDH_min, period_ps); + busy_timeout_cycles = TO_CYCLES(sdr->tWB_max + sdr->tR_max, period_ps); + + timing0 = (addr_setup_cycles << GPMI_TIMING0_ADDRESS_SETUP_OFFSET) | + (data_hold_cycles << GPMI_TIMING0_DATA_HOLD_OFFSET) | + (data_setup_cycles << GPMI_TIMING0_DATA_SETUP_OFFSET); + timing1 = (busy_timeout_cycles * 4096) << GPMI_TIMING1_DEVICE_BUSY_TIMEOUT_OFFSET; + + /* + * Derive NFC ideal delay from {3}: + * + * (tREA + 4000 - tRP) * 8 + * RDN_DELAY = ----------------------- + * RP + */ + if (period_ps > dll_threshold_ps) { + use_half_period = true; + reference_period_ps = period_ps / 2; + } else { + use_half_period = false; + reference_period_ps = period_ps; + } + + tRP_ps = data_setup_cycles * period_ps; + sample_delay_ps = (sdr->tREA_max + 4000 - tRP_ps) * 8; + if (sample_delay_ps > 0) + sample_delay_factor = sample_delay_ps / reference_period_ps; + else + sample_delay_factor = 0; + + ctrl1n = (wrn_dly_sel << GPMI_CTRL1_WRN_DLY_SEL_OFFSET); + if (sample_delay_factor) + ctrl1n |= (sample_delay_factor << GPMI_CTRL1_RDN_DELAY_OFFSET) | + GPMI_CTRL1_DLL_ENABLE | + (use_half_period ? GPMI_CTRL1_HALF_PERIOD : 0); + + + writel(timing0, &nand_info->gpmi_regs->hw_gpmi_timing0); + writel(timing1, &nand_info->gpmi_regs->hw_gpmi_timing1); + + /* + * Clear several CTRL1 fields, DLL must be disabled when setting + * RDN_DELAY or HALF_PERIOD. + */ + writel(GPMI_CTRL1_CLEAR_MASK, &nand_info->gpmi_regs->hw_gpmi_ctrl1_clr); + writel(ctrl1n, &nand_info->gpmi_regs->hw_gpmi_ctrl1_set); + + setup_gpmi_io_clk(clkcfg); + + /* Wait 64 clock cycles before using the GPMI after enabling the DLL */ + dll_wait_time_us = USEC_PER_SEC / clk_rate * 64; + if (!dll_wait_time_us) + dll_wait_time_us = 1; + + /* Wait for the DLL to settle. */ + udelay(dll_wait_time_us); +} + +static int mxs_nand_setup_interface(struct mtd_info *mtd, int chipnr, + const struct nand_data_interface *conf) +{ + struct nand_chip *chip = mtd_to_nand(mtd); + const struct nand_sdr_timings *sdr; + + + sdr = nand_get_sdr_timings(conf); + if (IS_ERR(sdr)) + return PTR_ERR(sdr); + + /* Stop here if this call was just a check */ + if (chipnr < 0) + return 0; + + /* Do the actual derivation of the controller timings */ + mxs_compute_timings(chip, sdr); + + return 0; +} + +#endif + int mxs_nand_init_spl(struct nand_chip *nand) { struct mxs_nand_info *nand_info; @@ -1342,16 +1549,16 @@ int mxs_nand_init_spl(struct nand_chip *nand)

nand->options |= NAND_NO_SUBPAGE_WRITE;

- nand->cmd_ctrl = mxs_nand_cmd_ctrl; - nand->dev_ready = mxs_nand_device_ready; - nand->select_chip = mxs_nand_select_chip; + nand->cmd_ctrl = mxs_nand_cmd_ctrl; + nand->dev_ready = mxs_nand_device_ready; + nand->select_chip = mxs_nand_select_chip;

- nand->read_byte = mxs_nand_read_byte; - nand->read_buf = mxs_nand_read_buf; + nand->read_byte = mxs_nand_read_byte; + nand->read_buf = mxs_nand_read_buf;

- nand->ecc.read_page = mxs_nand_ecc_read_page; + nand->ecc.read_page = mxs_nand_ecc_read_page;

- nand->ecc.mode = NAND_ECC_HW; + nand->ecc.mode = NAND_ECC_HW;

return 0; } @@ -1384,16 +1591,19 @@ int mxs_nand_init_ctrl(struct mxs_nand_info *nand_info) if (nand_info->dev) nand->flash_node = dev_of_offset(nand_info->dev);

- nand->cmd_ctrl = mxs_nand_cmd_ctrl; + nand->cmd_ctrl = mxs_nand_cmd_ctrl;

- nand->dev_ready = mxs_nand_device_ready; - nand->select_chip = mxs_nand_select_chip; - nand->block_bad = mxs_nand_block_bad; + nand->dev_ready = mxs_nand_device_ready; + nand->select_chip = mxs_nand_select_chip; + nand->block_bad = mxs_nand_block_bad;

- nand->read_byte = mxs_nand_read_byte; +#if (defined(CONFIG_MX6UL) || defined(CONFIG_MX6ULL)) + nand->setup_data_interface = mxs_nand_setup_interface; +#endif + nand->read_byte = mxs_nand_read_byte;

- nand->read_buf = mxs_nand_read_buf; - nand->write_buf = mxs_nand_write_buf; + nand->read_buf = mxs_nand_read_buf; + nand->write_buf = mxs_nand_write_buf;

/* first scan to find the device and get the page size */ if (nand_scan_ident(mtd, CONFIG_SYS_MAX_NAND_DEVICE, NULL)) diff --git a/drivers/mtd/nand/raw/mxs_nand_dt.c b/drivers/mtd/nand/raw/mxs_nand_dt.c index 18c042c7bb..872e5fe684 100644 --- a/drivers/mtd/nand/raw/mxs_nand_dt.c +++ b/drivers/mtd/nand/raw/mxs_nand_dt.c @@ -22,22 +22,27 @@

struct mxs_nand_dt_data { unsigned int max_ecc_strength_supported; + int max_chain_delay; /* See the async EDO mode */ };

static const struct mxs_nand_dt_data mxs_nand_imx6q_data = { .max_ecc_strength_supported = 40, + .max_chain_delay = 12000, };

static const struct mxs_nand_dt_data mxs_nand_imx6sx_data = { .max_ecc_strength_supported = 62, + .max_chain_delay = 12000, };

static const struct mxs_nand_dt_data mxs_nand_imx7d_data = { .max_ecc_strength_supported = 62, + .max_chain_delay = 12000, };

static const struct mxs_nand_dt_data mxs_nand_imx8qxp_data = { .max_ecc_strength_supported = 62, + .max_chain_delay = 12000, };

static const struct udevice_id mxs_nand_dt_ids[] = { @@ -72,8 +77,10 @@ static int mxs_nand_dt_probe(struct udevice *dev) int ret;

data = (void *)dev_get_driver_data(dev); - if (data) + if (data) { info->max_ecc_strength_supported = data->max_ecc_strength_supported; + info->max_chain_delay = data->max_chain_delay; + }

info->dev = dev;

diff --git a/include/mxs_nand.h b/include/mxs_nand.h index c0cefaca90..c7c6870ed9 100644 --- a/include/mxs_nand.h +++ b/include/mxs_nand.h @@ -42,6 +42,7 @@ struct mxs_nand_info { struct nand_chip chip; struct udevice *dev; unsigned int max_ecc_strength_supported; + int max_chain_delay; bool use_minimum_ecc; /* legacy bch geometry flag */ bool legacy_bch_geometry;