[U-Boot] [PATCH 2/2] spi: cadence-qspi: Add direct mode support
Vignesh Raghavendra
vigneshr at ti.com
Fri Oct 18 12:40:51 UTC 2019
Hi,
On 18/10/19 2:34 PM, Simon Goldschmidt wrote:
> On Thu, Oct 17, 2019 at 2:55 PM Simon Goldschmidt
> <simon.k.r.goldschmidt at gmail.com> wrote:
>>
>> On Thu, Oct 17, 2019 at 2:44 PM Vignesh Raghavendra <vigneshr at ti.com> wrote:
>>>
>>> Hi,
>>>
>>> On 17/10/19 5:09 PM, Simon Goldschmidt wrote:
>>>> On Mon, Oct 14, 2019 at 3:27 PM Vignesh Raghavendra <vigneshr at ti.com> wrote:
>>>>>
>>>>> Add support for Direct Access Controller mode of Cadence QSPI. This
>>>>> allows MMIO access to SPI NOR flash providing better read performance.
>>>>>
>>>>> Signed-off-by: Vignesh R <vigneshr at ti.com>
>>>>> Signed-off-by: Vignesh Raghavendra <vigneshr at ti.com>
>>>>
>>>> I've tested this on my socfpga cyclone5 board with an mt25ql256a (running at
>>>> 50MHz) and it seems to work fine.
>>>>
>>>> However, I had the impression it was a bit slower, not faster, although I
>>>> haven't measured, and running at 50MHz with 4 data lines, reading the whole
>>>> flash takes about 1.5 seconds only, so without actually measureing it, it's
>>>> hard to tell if this performance is really worth the 440 bytes of extra code
>>>> it adds?
>>>>
>>>
>>> I should have noted in the commit msg that direct mode is used only when
>>> AHB window is at least 8MB. Working with smaller window sizes would mean
>>> code would fall back to indirect mode most of the time.
>>> I see that socfgpa don't seem to have large AHB windows and therefore
>>> would not use direct access mode.
>>
>> Aha. Yes, socfpga gen5 has a 1MB window only, I think. So the speed hasn't
>> changed.
>>
>>>
>>> On TI platforms its possible to use DMA to read data from memory mapped
>>> region using mem to mem DMA channels which improves throughput by 5 times.
>>
>> Hmm, I'm using a QSPI at 50 MHz and transferring 31 MByte takes about 1.5
>> seconds. The maximum speed of that setup would be 25 MByte/s without any
>> overhead (1.24 seconds for 31 MB). There's no way I could achieve an improvement
>> by 5 on my platform!
>>
>>>
>>>> Note that I'm already short on RAM in SPL (socfpga gen5), so these 440 bytes
>>>> do hurt. Note that patch 1/2 of this series reduced SPL code size by 320 bytes
>>>> for me :-)
>>>>
>>>
>>> Hmm, I read this as patch 1 brings down memory consumption by 320 bytes
>>> and patch 2 adds 440 bytes (delta being +120 bytes for entire series).
>>> I can see if size can be optimized, but would like to avoid #ifdef'ery
>>> within the driver if possible.
>>
>> Well, I can only say I'm currently struggling to keep SPI-NOR and MMC enabled
>> at the same time in socfpga_socrates (moving more code to DM). And even if it
>> sounds like not much, 440 bytes *are* much for me at this point.
>>
>> I still would prefer having a Kconfig option for this that can be disabled
>> for socfpga.
>
> Oh well, maybe just go ahead adding this and I'll try how it fits. We can alway
> add reduced functionality later by checking for CONFIG_SPL_SPI_FLASH_TINY,
> whicht might be a better config option to guard this than something cadence-qspi
> specific.
>
Okay, thanks! Guarding with CONFIG_SPL_SPI_FLASH_TINY as and where
required seems fair idea. BTW, it would be great if you could confirm
Quad read works fine when spi-tx-bus-width = 1 and spi-rx-bus-width = 4
as I suggested in other thread?
Regards
Vignesh
> Regards,
> Simon
>
>>
>> Regards,
>> Simon
>>
>>>
>>> Regards
>>> Vignesh
>>>
>>>> Regards,
>>>> Simon
>>>>
>>>>
>>>>> ---
>>>>> drivers/spi/cadence_qspi.c | 40 ++++++++++++----------
>>>>> drivers/spi/cadence_qspi.h | 19 ++++++-----
>>>>> drivers/spi/cadence_qspi_apb.c | 61 +++++++++++++++++++++++++++++-----
>>>>> 3 files changed, 87 insertions(+), 33 deletions(-)
>>>>>
>>>>> diff --git a/drivers/spi/cadence_qspi.c b/drivers/spi/cadence_qspi.c
>>>>> index 673a2e9a6c4c..6c98cbf39ae4 100644
>>>>> --- a/drivers/spi/cadence_qspi.c
>>>>> +++ b/drivers/spi/cadence_qspi.c
>>>>> @@ -12,12 +12,13 @@
>>>>> #include <spi.h>
>>>>> #include <spi-mem.h>
>>>>> #include <linux/errno.h>
>>>>> +#include <linux/sizes.h>
>>>>> #include "cadence_qspi.h"
>>>>>
>>>>> #define CQSPI_STIG_READ 0
>>>>> #define CQSPI_STIG_WRITE 1
>>>>> -#define CQSPI_INDIRECT_READ 2
>>>>> -#define CQSPI_INDIRECT_WRITE 3
>>>>> +#define CQSPI_READ 2
>>>>> +#define CQSPI_WRITE 3
>>>>>
>>>>> static int cadence_spi_write_speed(struct udevice *bus, uint hz)
>>>>> {
>>>>> @@ -189,6 +190,7 @@ static int cadence_spi_remove(struct udevice *dev)
>>>>>
>>>>> static int cadence_spi_set_mode(struct udevice *bus, uint mode)
>>>>> {
>>>>> + struct cadence_spi_platdata *plat = bus->platdata;
>>>>> struct cadence_spi_priv *priv = dev_get_priv(bus);
>>>>>
>>>>> /* Disable QSPI */
>>>>> @@ -197,6 +199,10 @@ static int cadence_spi_set_mode(struct udevice *bus, uint mode)
>>>>> /* Set SPI mode */
>>>>> cadence_qspi_apb_set_clk_mode(priv->regbase, mode);
>>>>>
>>>>> + /* Enable Direct Access Controller */
>>>>> + if (plat->use_dac_mode)
>>>>> + cadence_qspi_apb_dac_mode_enable(priv->regbase);
>>>>> +
>>>>> /* Enable QSPI */
>>>>> cadence_qspi_apb_controller_enable(priv->regbase);
>>>>>
>>>>> @@ -221,12 +227,12 @@ static int cadence_spi_mem_exec_op(struct spi_slave *spi,
>>>>> if (!op->addr.nbytes)
>>>>> mode = CQSPI_STIG_READ;
>>>>> else
>>>>> - mode = CQSPI_INDIRECT_READ;
>>>>> + mode = CQSPI_READ;
>>>>> } else {
>>>>> if (!op->addr.nbytes || !op->data.buf.out)
>>>>> mode = CQSPI_STIG_WRITE;
>>>>> else
>>>>> - mode = CQSPI_INDIRECT_WRITE;
>>>>> + mode = CQSPI_WRITE;
>>>>> }
>>>>>
>>>>> switch (mode) {
>>>>> @@ -236,19 +242,15 @@ static int cadence_spi_mem_exec_op(struct spi_slave *spi,
>>>>> case CQSPI_STIG_WRITE:
>>>>> err = cadence_qspi_apb_command_write(base, op);
>>>>> break;
>>>>> - case CQSPI_INDIRECT_READ:
>>>>> - err = cadence_qspi_apb_indirect_read_setup(plat, op);
>>>>> - if (!err) {
>>>>> - err = cadence_qspi_apb_indirect_read_execute
>>>>> - (plat, op->data.nbytes, op->data.buf.in);
>>>>> - }
>>>>> + case CQSPI_READ:
>>>>> + err = cadence_qspi_apb_read_setup(plat, op);
>>>>> + if (!err)
>>>>> + err = cadence_qspi_apb_read_execute(plat, op);
>>>>> break;
>>>>> - case CQSPI_INDIRECT_WRITE:
>>>>> - err = cadence_qspi_apb_indirect_write_setup(plat, op);
>>>>> - if (!err) {
>>>>> - err = cadence_qspi_apb_indirect_write_execute
>>>>> - (plat, op->data.nbytes, op->data.buf.out);
>>>>> - }
>>>>> + case CQSPI_WRITE:
>>>>> + err = cadence_qspi_apb_write_setup(plat, op);
>>>>> + if (!err)
>>>>> + err = cadence_qspi_apb_write_execute(plat, op);
>>>>> break;
>>>>> default:
>>>>> err = -1;
>>>>> @@ -264,13 +266,17 @@ static int cadence_spi_ofdata_to_platdata(struct udevice *bus)
>>>>> ofnode subnode;
>>>>>
>>>>> plat->regbase = (void *)devfdt_get_addr_index(bus, 0);
>>>>> - plat->ahbbase = (void *)devfdt_get_addr_index(bus, 1);
>>>>> + plat->ahbbase = (void *)devfdt_get_addr_size_index(bus, 1,
>>>>> + &plat->ahbsize);
>>>>> plat->is_decoded_cs = dev_read_bool(bus, "cdns,is-decoded-cs");
>>>>> plat->fifo_depth = dev_read_u32_default(bus, "cdns,fifo-depth", 128);
>>>>> plat->fifo_width = dev_read_u32_default(bus, "cdns,fifo-width", 4);
>>>>> plat->trigger_address = dev_read_u32_default(bus,
>>>>> "cdns,trigger-address",
>>>>> 0);
>>>>> + /* Use DAC mode only when MMIO window is at least 8M wide */
>>>>> + if (plat->ahbsize >= SZ_8M)
>>>>> + plat->use_dac_mode = true;
>>>>>
>>>>> /* All other paramters are embedded in the child node */
>>>>> subnode = dev_read_first_subnode(bus);
>>>>> diff --git a/drivers/spi/cadence_qspi.h b/drivers/spi/cadence_qspi.h
>>>>> index e655b027d788..619f0bed8efd 100644
>>>>> --- a/drivers/spi/cadence_qspi.h
>>>>> +++ b/drivers/spi/cadence_qspi.h
>>>>> @@ -23,6 +23,8 @@ struct cadence_spi_platdata {
>>>>> u32 fifo_depth;
>>>>> u32 fifo_width;
>>>>> u32 trigger_address;
>>>>> + fdt_addr_t ahbsize;
>>>>> + bool use_dac_mode;
>>>>>
>>>>> /* Flash parameters */
>>>>> u32 page_size;
>>>>> @@ -52,20 +54,21 @@ struct cadence_spi_priv {
>>>>> void cadence_qspi_apb_controller_init(struct cadence_spi_platdata *plat);
>>>>> void cadence_qspi_apb_controller_enable(void *reg_base_addr);
>>>>> void cadence_qspi_apb_controller_disable(void *reg_base_addr);
>>>>> +void cadence_qspi_apb_dac_mode_enable(void *reg_base);
>>>>>
>>>>> int cadence_qspi_apb_command_read(void *reg_base_addr,
>>>>> const struct spi_mem_op *op);
>>>>> int cadence_qspi_apb_command_write(void *reg_base_addr,
>>>>> const struct spi_mem_op *op);
>>>>>
>>>>> -int cadence_qspi_apb_indirect_read_setup(struct cadence_spi_platdata *plat,
>>>>> - const struct spi_mem_op *op);
>>>>> -int cadence_qspi_apb_indirect_read_execute(struct cadence_spi_platdata *plat,
>>>>> - unsigned int rxlen, u8 *rxbuf);
>>>>> -int cadence_qspi_apb_indirect_write_setup(struct cadence_spi_platdata *plat,
>>>>> - const struct spi_mem_op *op);
>>>>> -int cadence_qspi_apb_indirect_write_execute(struct cadence_spi_platdata *plat,
>>>>> - unsigned int txlen, const u8 *txbuf);
>>>>> +int cadence_qspi_apb_read_setup(struct cadence_spi_platdata *plat,
>>>>> + const struct spi_mem_op *op);
>>>>> +int cadence_qspi_apb_read_execute(struct cadence_spi_platdata *plat,
>>>>> + const struct spi_mem_op *op);
>>>>> +int cadence_qspi_apb_write_setup(struct cadence_spi_platdata *plat,
>>>>> + const struct spi_mem_op *op);
>>>>> +int cadence_qspi_apb_write_execute(struct cadence_spi_platdata *plat,
>>>>> + const struct spi_mem_op *op);
>>>>>
>>>>> void cadence_qspi_apb_chipselect(void *reg_base,
>>>>> unsigned int chip_select, unsigned int decoder_enable);
>>>>> diff --git a/drivers/spi/cadence_qspi_apb.c b/drivers/spi/cadence_qspi_apb.c
>>>>> index 8dd0495dfcf4..fd491f2c8104 100644
>>>>> --- a/drivers/spi/cadence_qspi_apb.c
>>>>> +++ b/drivers/spi/cadence_qspi_apb.c
>>>>> @@ -189,6 +189,15 @@ void cadence_qspi_apb_controller_disable(void *reg_base)
>>>>> writel(reg, reg_base + CQSPI_REG_CONFIG);
>>>>> }
>>>>>
>>>>> +void cadence_qspi_apb_dac_mode_enable(void *reg_base)
>>>>> +{
>>>>> + unsigned int reg;
>>>>> +
>>>>> + reg = readl(reg_base + CQSPI_REG_CONFIG);
>>>>> + reg |= CQSPI_REG_CONFIG_DIRECT;
>>>>> + writel(reg, reg_base + CQSPI_REG_CONFIG);
>>>>> +}
>>>>> +
>>>>> /* Return 1 if idle, otherwise return 0 (busy). */
>>>>> static unsigned int cadence_qspi_wait_idle(void *reg_base)
>>>>> {
>>>>> @@ -512,8 +521,8 @@ int cadence_qspi_apb_command_write(void *reg_base, const struct spi_mem_op *op)
>>>>> }
>>>>>
>>>>> /* Opcode + Address (3/4 bytes) + dummy bytes (0-4 bytes) */
>>>>> -int cadence_qspi_apb_indirect_read_setup(struct cadence_spi_platdata *plat,
>>>>> - const struct spi_mem_op *op)
>>>>> +int cadence_qspi_apb_read_setup(struct cadence_spi_platdata *plat,
>>>>> + const struct spi_mem_op *op)
>>>>> {
>>>>> unsigned int reg;
>>>>> unsigned int rd_reg;
>>>>> @@ -577,8 +586,9 @@ static int cadence_qspi_wait_for_data(struct cadence_spi_platdata *plat)
>>>>> return -ETIMEDOUT;
>>>>> }
>>>>>
>>>>> -int cadence_qspi_apb_indirect_read_execute(struct cadence_spi_platdata *plat,
>>>>> - unsigned int n_rx, u8 *rxbuf)
>>>>> +static int
>>>>> +cadence_qspi_apb_indirect_read_execute(struct cadence_spi_platdata *plat,
>>>>> + unsigned int n_rx, u8 *rxbuf)
>>>>> {
>>>>> unsigned int remaining = n_rx;
>>>>> unsigned int bytes_to_read = 0;
>>>>> @@ -639,9 +649,26 @@ failrd:
>>>>> return ret;
>>>>> }
>>>>>
>>>>> +int cadence_qspi_apb_read_execute(struct cadence_spi_platdata *plat,
>>>>> + const struct spi_mem_op *op)
>>>>> +{
>>>>> + u32 from = op->addr.val;
>>>>> + void *buf = op->data.buf.in;
>>>>> + size_t len = op->data.nbytes;
>>>>> +
>>>>> + if (plat->use_dac_mode && (from + len < plat->ahbsize)) {
>>>>> + memcpy_fromio(buf, plat->ahbbase + from, len);
>>>>> + if (!cadence_qspi_wait_idle(plat->regbase))
>>>>> + return -EIO;
>>>>> + return 0;
>>>>> + }
>>>>> +
>>>>> + return cadence_qspi_apb_indirect_read_execute(plat, len, buf);
>>>>> +}
>>>>> +
>>>>> /* Opcode + Address (3/4 bytes) */
>>>>> -int cadence_qspi_apb_indirect_write_setup(struct cadence_spi_platdata *plat,
>>>>> - const struct spi_mem_op *op)
>>>>> +int cadence_qspi_apb_write_setup(struct cadence_spi_platdata *plat,
>>>>> + const struct spi_mem_op *op)
>>>>> {
>>>>> unsigned int reg;
>>>>>
>>>>> @@ -662,8 +689,9 @@ int cadence_qspi_apb_indirect_write_setup(struct cadence_spi_platdata *plat,
>>>>> return 0;
>>>>> }
>>>>>
>>>>> -int cadence_qspi_apb_indirect_write_execute(struct cadence_spi_platdata *plat,
>>>>> - unsigned int n_tx, const u8 *txbuf)
>>>>> +static int
>>>>> +cadence_qspi_apb_indirect_write_execute(struct cadence_spi_platdata *plat,
>>>>> + unsigned int n_tx, const u8 *txbuf)
>>>>> {
>>>>> unsigned int page_size = plat->page_size;
>>>>> unsigned int remaining = n_tx;
>>>>> @@ -735,6 +763,23 @@ failwr:
>>>>> return ret;
>>>>> }
>>>>>
>>>>> +int cadence_qspi_apb_write_execute(struct cadence_spi_platdata *plat,
>>>>> + const struct spi_mem_op *op)
>>>>> +{
>>>>> + u32 to = op->addr.val;
>>>>> + const void *buf = op->data.buf.out;
>>>>> + size_t len = op->data.nbytes;
>>>>> +
>>>>> + if (plat->use_dac_mode && (to + len < plat->ahbsize)) {
>>>>> + memcpy_toio(plat->ahbbase + to, buf, len);
>>>>> + if (!cadence_qspi_wait_idle(plat->regbase))
>>>>> + return -EIO;
>>>>> + return 0;
>>>>> + }
>>>>> +
>>>>> + return cadence_qspi_apb_indirect_write_execute(plat, len, buf);
>>>>> +}
>>>>> +
>>>>> void cadence_qspi_apb_enter_xip(void *reg_base, char xip_dummy)
>>>>> {
>>>>> unsigned int reg;
>>>>> --
>>>>> 2.23.0
>>>>>
>>>
>>> --
>>> Regards
>>> Vignesh
--
Regards
Vignesh
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