#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,
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);
/* 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;
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;
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;
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;
(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.
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;
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)
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. */
projects / deliverable / linux.git / blobdiff