diff options
Diffstat (limited to 'drivers/mtd/nand/gpmi-nand/gpmi-lib.c')
| -rw-r--r-- | drivers/mtd/nand/gpmi-nand/gpmi-lib.c | 322 |
1 files changed, 286 insertions, 36 deletions
diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c index a1f43329ad4..3502accd4bc 100644 --- a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c +++ b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c @@ -26,7 +26,7 @@ #include "gpmi-regs.h" #include "bch-regs.h" -struct timing_threshod timing_default_threshold = { +static struct timing_threshod timing_default_threshold = { .max_data_setup_cycles = (BM_GPMI_TIMING0_DATA_SETUP >> BP_GPMI_TIMING0_DATA_SETUP), .internal_data_setup_in_ns = 0, @@ -124,12 +124,42 @@ error: return -ETIMEDOUT; } +static int __gpmi_enable_clk(struct gpmi_nand_data *this, bool v) +{ + struct clk *clk; + int ret; + int i; + + for (i = 0; i < GPMI_CLK_MAX; i++) { + clk = this->resources.clock[i]; + if (!clk) + break; + + if (v) { + ret = clk_prepare_enable(clk); + if (ret) + goto err_clk; + } else { + clk_disable_unprepare(clk); + } + } + return 0; + +err_clk: + for (; i > 0; i--) + clk_disable_unprepare(this->resources.clock[i - 1]); + return ret; +} + +#define gpmi_enable_clk(x) __gpmi_enable_clk(x, true) +#define gpmi_disable_clk(x) __gpmi_enable_clk(x, false) + int gpmi_init(struct gpmi_nand_data *this) { struct resources *r = &this->resources; int ret; - ret = clk_prepare_enable(r->clock); + ret = gpmi_enable_clk(this); if (ret) goto err_out; ret = gpmi_reset_block(r->gpmi_regs, false); @@ -149,7 +179,7 @@ int gpmi_init(struct gpmi_nand_data *this) /* Select BCH ECC. */ writel(BM_GPMI_CTRL1_BCH_MODE, r->gpmi_regs + HW_GPMI_CTRL1_SET); - clk_disable_unprepare(r->clock); + gpmi_disable_clk(this); return 0; err_out: return ret; @@ -205,7 +235,7 @@ int bch_set_geometry(struct gpmi_nand_data *this) ecc_strength = bch_geo->ecc_strength >> 1; page_size = bch_geo->page_size; - ret = clk_prepare_enable(r->clock); + ret = gpmi_enable_clk(this); if (ret) goto err_out; @@ -240,7 +270,7 @@ int bch_set_geometry(struct gpmi_nand_data *this) writel(BM_BCH_CTRL_COMPLETE_IRQ_EN, r->bch_regs + HW_BCH_CTRL_SET); - clk_disable_unprepare(r->clock); + gpmi_disable_clk(this); return 0; err_out: return ret; @@ -263,6 +293,7 @@ static int gpmi_nfc_compute_hardware_timing(struct gpmi_nand_data *this, struct gpmi_nfc_hardware_timing *hw) { struct timing_threshod *nfc = &timing_default_threshold; + struct resources *r = &this->resources; struct nand_chip *nand = &this->nand; struct nand_timing target = this->timing; bool improved_timing_is_available; @@ -302,8 +333,9 @@ static int gpmi_nfc_compute_hardware_timing(struct gpmi_nand_data *this, (target.tRHOH_in_ns >= 0) ; /* Inspect the clock. */ + nfc->clock_frequency_in_hz = clk_get_rate(r->clock[0]); clock_frequency_in_hz = nfc->clock_frequency_in_hz; - clock_period_in_ns = 1000000000 / clock_frequency_in_hz; + clock_period_in_ns = NSEC_PER_SEC / clock_frequency_in_hz; /* * The NFC quantizes setup and hold parameters in terms of clock cycles. @@ -698,17 +730,230 @@ return_results: hw->address_setup_in_cycles = address_setup_in_cycles; hw->use_half_periods = dll_use_half_periods; hw->sample_delay_factor = sample_delay_factor; + hw->device_busy_timeout = GPMI_DEFAULT_BUSY_TIMEOUT; + hw->wrn_dly_sel = BV_GPMI_CTRL1_WRN_DLY_SEL_4_TO_8NS; /* Return success. */ return 0; } +/* + * <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. From the ONFI nand standards, + * we know that tREA is 16ns in mode 5, tREA is 20ns is mode 4. + * Please check it in : www.onfi.org + * C : a constant for adjust the delay. default is 4. + * tRP : the read pulse width. + * Specified by the HW_GPMI_TIMING0:DATA_SETUP: + * 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 16ns, but in mx6q, we use 12ns. + * + * 4.3) since {1} equals {2}, we get: + * + * (tREA + 4 - tRP) * 8 + * RDN_DELAY = --------------------- {3} + * RP + * + * 4.4) We only support the fastest asynchronous mode of ONFI nand. + * For some ONFI nand, the mode 4 is the fastest mode; + * while for some ONFI nand, the mode 5 is the fastest mode. + * So we only support the mode 4 and mode 5. It is no need to + * support other modes. + */ +static void gpmi_compute_edo_timing(struct gpmi_nand_data *this, + struct gpmi_nfc_hardware_timing *hw) +{ + struct resources *r = &this->resources; + unsigned long rate = clk_get_rate(r->clock[0]); + int mode = this->timing_mode; + int dll_threshold = 16; /* in ns */ + unsigned long delay; + unsigned long clk_period; + int t_rea; + int c = 4; + int t_rp; + int rp; + + /* + * [1] for GPMI_HW_GPMI_TIMING0: + * The async mode requires 40MHz for mode 4, 50MHz for mode 5. + * The GPMI can support 100MHz at most. So if we want to + * get the 40MHz or 50MHz, we have to set DS=1, DH=1. + * Set the ADDRESS_SETUP to 0 in mode 4. + */ + hw->data_setup_in_cycles = 1; + hw->data_hold_in_cycles = 1; + hw->address_setup_in_cycles = ((mode == 5) ? 1 : 0); + + /* [2] for GPMI_HW_GPMI_TIMING1 */ + hw->device_busy_timeout = 0x9000; + + /* [3] for GPMI_HW_GPMI_CTRL1 */ + hw->wrn_dly_sel = BV_GPMI_CTRL1_WRN_DLY_SEL_NO_DELAY; + + if (GPMI_IS_MX6Q(this)) + dll_threshold = 12; + + /* + * Enlarge 10 times for the numerator and denominator in {3}. + * This make us to get more accurate result. + */ + clk_period = NSEC_PER_SEC / (rate / 10); + dll_threshold *= 10; + t_rea = ((mode == 5) ? 16 : 20) * 10; + c *= 10; + + t_rp = clk_period * 1; /* DATA_SETUP is 1 */ + + if (clk_period > dll_threshold) { + hw->use_half_periods = 1; + rp = clk_period / 2; + } else { + hw->use_half_periods = 0; + rp = clk_period; + } + + /* + * Multiply the numerator with 10, we could do a round off: + * 7.8 round up to 8; 7.4 round down to 7. + */ + delay = (((t_rea + c - t_rp) * 8) * 10) / rp; + delay = (delay + 5) / 10; + + hw->sample_delay_factor = delay; +} + +static int enable_edo_mode(struct gpmi_nand_data *this, int mode) +{ + struct resources *r = &this->resources; + struct nand_chip *nand = &this->nand; + struct mtd_info *mtd = &this->mtd; + uint8_t feature[ONFI_SUBFEATURE_PARAM_LEN] = {}; + unsigned long rate; + int ret; + + nand->select_chip(mtd, 0); + + /* [1] send SET FEATURE commond to NAND */ + feature[0] = mode; + ret = nand->onfi_set_features(mtd, nand, + ONFI_FEATURE_ADDR_TIMING_MODE, feature); + if (ret) + goto err_out; + + /* [2] send GET FEATURE command to double-check the timing mode */ + memset(feature, 0, ONFI_SUBFEATURE_PARAM_LEN); + ret = nand->onfi_get_features(mtd, nand, + ONFI_FEATURE_ADDR_TIMING_MODE, feature); + if (ret || feature[0] != mode) + goto err_out; + + nand->select_chip(mtd, -1); + + /* [3] set the main IO clock, 100MHz for mode 5, 80MHz for mode 4. */ + rate = (mode == 5) ? 100000000 : 80000000; + clk_set_rate(r->clock[0], rate); + + /* Let the gpmi_begin() re-compute the timing again. */ + this->flags &= ~GPMI_TIMING_INIT_OK; + + this->flags |= GPMI_ASYNC_EDO_ENABLED; + this->timing_mode = mode; + dev_info(this->dev, "enable the asynchronous EDO mode %d\n", mode); + return 0; + +err_out: + nand->select_chip(mtd, -1); + dev_err(this->dev, "mode:%d ,failed in set feature.\n", mode); + return -EINVAL; +} + +int gpmi_extra_init(struct gpmi_nand_data *this) +{ + struct nand_chip *chip = &this->nand; + + /* Enable the asynchronous EDO feature. */ + if (GPMI_IS_MX6Q(this) && chip->onfi_version) { + int mode = onfi_get_async_timing_mode(chip); + + /* We only support the timing mode 4 and mode 5. */ + if (mode & ONFI_TIMING_MODE_5) + mode = 5; + else if (mode & ONFI_TIMING_MODE_4) + mode = 4; + else + return 0; + + return enable_edo_mode(this, mode); + } + return 0; +} + /* Begin the I/O */ void gpmi_begin(struct gpmi_nand_data *this) { struct resources *r = &this->resources; - struct timing_threshod *nfc = &timing_default_threshold; - unsigned char *gpmi_regs = r->gpmi_regs; + void __iomem *gpmi_regs = r->gpmi_regs; unsigned int clock_period_in_ns; uint32_t reg; unsigned int dll_wait_time_in_us; @@ -716,60 +961,66 @@ void gpmi_begin(struct gpmi_nand_data *this) int ret; /* Enable the clock. */ - ret = clk_prepare_enable(r->clock); + ret = gpmi_enable_clk(this); if (ret) { pr_err("We failed in enable the clk\n"); goto err_out; } - /* set ready/busy timeout */ - writel(0x500 << BP_GPMI_TIMING1_BUSY_TIMEOUT, - gpmi_regs + HW_GPMI_TIMING1); - - /* Get the timing information we need. */ - nfc->clock_frequency_in_hz = clk_get_rate(r->clock); - clock_period_in_ns = 1000000000 / nfc->clock_frequency_in_hz; + /* Only initialize the timing once */ + if (this->flags & GPMI_TIMING_INIT_OK) + return; + this->flags |= GPMI_TIMING_INIT_OK; - gpmi_nfc_compute_hardware_timing(this, &hw); + if (this->flags & GPMI_ASYNC_EDO_ENABLED) + gpmi_compute_edo_timing(this, &hw); + else + gpmi_nfc_compute_hardware_timing(this, &hw); - /* Set up all the simple timing parameters. */ + /* [1] Set HW_GPMI_TIMING0 */ reg = BF_GPMI_TIMING0_ADDRESS_SETUP(hw.address_setup_in_cycles) | BF_GPMI_TIMING0_DATA_HOLD(hw.data_hold_in_cycles) | BF_GPMI_TIMING0_DATA_SETUP(hw.data_setup_in_cycles) ; writel(reg, gpmi_regs + HW_GPMI_TIMING0); - /* - * DLL_ENABLE must be set to 0 when setting RDN_DELAY or HALF_PERIOD. - */ + /* [2] Set HW_GPMI_TIMING1 */ + writel(BF_GPMI_TIMING1_BUSY_TIMEOUT(hw.device_busy_timeout), + gpmi_regs + HW_GPMI_TIMING1); + + /* [3] The following code is to set the HW_GPMI_CTRL1. */ + + /* Set the WRN_DLY_SEL */ + writel(BM_GPMI_CTRL1_WRN_DLY_SEL, gpmi_regs + HW_GPMI_CTRL1_CLR); + writel(BF_GPMI_CTRL1_WRN_DLY_SEL(hw.wrn_dly_sel), + gpmi_regs + HW_GPMI_CTRL1_SET); + + /* DLL_ENABLE must be set to 0 when setting RDN_DELAY or HALF_PERIOD. */ writel(BM_GPMI_CTRL1_DLL_ENABLE, gpmi_regs + HW_GPMI_CTRL1_CLR); /* Clear out the DLL control fields. */ - writel(BM_GPMI_CTRL1_RDN_DELAY, gpmi_regs + HW_GPMI_CTRL1_CLR); - writel(BM_GPMI_CTRL1_HALF_PERIOD, gpmi_regs + HW_GPMI_CTRL1_CLR); + reg = BM_GPMI_CTRL1_RDN_DELAY | BM_GPMI_CTRL1_HALF_PERIOD; + writel(reg, gpmi_regs + HW_GPMI_CTRL1_CLR); /* If no sample delay is called for, return immediately. */ if (!hw.sample_delay_factor) return; - /* Configure the HALF_PERIOD flag. */ - if (hw.use_half_periods) - writel(BM_GPMI_CTRL1_HALF_PERIOD, - gpmi_regs + HW_GPMI_CTRL1_SET); + /* Set RDN_DELAY or HALF_PERIOD. */ + reg = ((hw.use_half_periods) ? BM_GPMI_CTRL1_HALF_PERIOD : 0) + | BF_GPMI_CTRL1_RDN_DELAY(hw.sample_delay_factor); - /* Set the delay factor. */ - writel(BF_GPMI_CTRL1_RDN_DELAY(hw.sample_delay_factor), - gpmi_regs + HW_GPMI_CTRL1_SET); + writel(reg, gpmi_regs + HW_GPMI_CTRL1_SET); - /* Enable the DLL. */ + /* At last, we enable the DLL. */ writel(BM_GPMI_CTRL1_DLL_ENABLE, gpmi_regs + HW_GPMI_CTRL1_SET); /* * After we enable the GPMI DLL, we have to wait 64 clock cycles before - * we can use the GPMI. - * - * Calculate the amount of time we need to wait, in microseconds. + * we can use the GPMI. Calculate the amount of time we need to wait, + * in microseconds. */ + clock_period_in_ns = NSEC_PER_SEC / clk_get_rate(r->clock[0]); dll_wait_time_in_us = (clock_period_in_ns * 64) / 1000; if (!dll_wait_time_in_us) @@ -784,8 +1035,7 @@ err_out: void gpmi_end(struct gpmi_nand_data *this) { - struct resources *r = &this->resources; - clk_disable_unprepare(r->clock); + gpmi_disable_clk(this); } /* Clears a BCH interrupt. */ |