[U-Boot] [PATCH 02/15 v2] spi: Add driver for Marvell Armada 3700 SoC
Jagan Teki
jagannadh.teki at gmail.com
Fri Sep 23 16:03:54 CEST 2016
On Fri, Sep 23, 2016 at 6:54 PM, Stefan Roese <sr at denx.de> wrote:
> On 23.09.2016 14:53, Jagan Teki wrote:
>>
>> On Fri, Sep 23, 2016 at 5:47 PM, Stefan Roese <sr at denx.de> wrote:
>>>
>>> The SPI IP core in the Marvell Armada 3700 is similar to the one in the
>>> other Armada SoCs. But the differences are big enough that it makes
>>> sense to introduce a new driver instead of cluttering the old
>>> kirkwood driver with #ifdef's.
>>>
>>> Signed-off-by: Stefan Roese <sr at denx.de>
>>> Cc: Nadav Haklai <nadavh at marvell.com>
>>> Cc: Kostya Porotchkin <kostap at marvell.com>
>>> Cc: Wilson Ding <dingwei at marvell.com>
>>> Cc: Victor Gu <xigu at marvell.com>
>>> Cc: Hua Jing <jinghua at marvell.com>
>>> Cc: Terry Zhou <bjzhou at marvell.com>
>>> Cc: Hanna Hawa <hannah at marvell.com>
>>> Cc: Haim Boot <hayim at marvell.com>
>>> Cc: Jagan Teki <jteki at openedev.com>
>>> ---
>>> v2:
>>> - Evaluated hz and used values provided by the DT in
>>> mvebu_spi_set_speed()
>>> as suggested by Jagan
>>>
>>> drivers/spi/Kconfig | 7 +
>>> drivers/spi/Makefile | 1 +
>>> drivers/spi/mvebu_a3700_spi.c | 289
>>> ++++++++++++++++++++++++++++++++++++++++++
>>> 3 files changed, 297 insertions(+)
>>> create mode 100644 drivers/spi/mvebu_a3700_spi.c
>>>
>>> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
>>> index 5da66a6..8724f87 100644
>>> --- a/drivers/spi/Kconfig
>>> +++ b/drivers/spi/Kconfig
>>> @@ -68,6 +68,13 @@ config ICH_SPI
>>> access the SPI NOR flash on platforms embedding this Intel
>>> ICH IP core.
>>>
>>> +config MVEBU_A3700_SPI
>>> + bool "Marvell Armada 3700 SPI driver"
>>> + help
>>> + Enable the Marvell Armada 3700 SPI driver. This driver can be
>>> + used to access the SPI NOR flash on platforms embedding this
>>> + Marvell IP core.
>>> +
>>> config PIC32_SPI
>>> bool "Microchip PIC32 SPI driver"
>>> depends on MACH_PIC32
>>> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
>>> index b1d9e20..247c5f6 100644
>>> --- a/drivers/spi/Makefile
>>> +++ b/drivers/spi/Makefile
>>> @@ -37,6 +37,7 @@ obj-$(CONFIG_KIRKWOOD_SPI) += kirkwood_spi.o
>>> obj-$(CONFIG_LPC32XX_SSP) += lpc32xx_ssp.o
>>> obj-$(CONFIG_MPC52XX_SPI) += mpc52xx_spi.o
>>> obj-$(CONFIG_MPC8XXX_SPI) += mpc8xxx_spi.o
>>> +obj-$(CONFIG_MVEBU_A3700_SPI) += mvebu_a3700_spi.o
>>> obj-$(CONFIG_MXC_SPI) += mxc_spi.o
>>> obj-$(CONFIG_MXS_SPI) += mxs_spi.o
>>> obj-$(CONFIG_OMAP3_SPI) += omap3_spi.o
>>> diff --git a/drivers/spi/mvebu_a3700_spi.c
>>> b/drivers/spi/mvebu_a3700_spi.c
>>> new file mode 100644
>>> index 0000000..b566e03
>>> --- /dev/null
>>> +++ b/drivers/spi/mvebu_a3700_spi.c
>>> @@ -0,0 +1,289 @@
>>> +/*
>>> + * Copyright (C) 2015 Marvell International Ltd.
>>> + *
>>> + * Copyright (C) 2016 Stefan Roese <sr at denx.de>
>>> + *
>>> + * SPDX-License-Identifier: GPL-2.0+
>>> + */
>>> +
>>> +#include <common.h>
>>> +#include <dm.h>
>>> +#include <malloc.h>
>>> +#include <spi.h>
>>> +#include <wait_bit.h>
>>> +#include <asm/io.h>
>>> +
>>> +DECLARE_GLOBAL_DATA_PTR;
>>> +
>>> +#define SPI_TIMEOUT 10000
>>> +
>>> +#define MVEBU_SPI_A3700_XFER_RDY BIT(1)
>>> +#define MVEBU_SPI_A3700_FIFO_FLUSH BIT(9)
>>> +#define MVEBU_SPI_A3700_BYTE_LEN BIT(5)
>>> +#define MVEBU_SPI_A3700_CLK_PHA BIT(6)
>>> +#define MVEBU_SPI_A3700_CLK_POL BIT(7)
>>> +#define MVEBU_SPI_A3700_FIFO_EN BIT(17)
>>> +#define MVEBU_SPI_A3700_SPI_EN_0 BIT(16)
>>> +#define MVEBU_SPI_A3700_CLK_PRESCALE_BIT 0
>>> +#define MVEBU_SPI_A3700_CLK_PRESCALE_MASK \
>>> + (0x1f << MVEBU_SPI_A3700_CLK_PRESCALE_BIT)
>>> +
>>> +/* SPI registers */
>>> +struct spi_reg {
>>> + u32 ctrl; /* 0x10600 */
>>> + u32 cfg; /* 0x10604 */
>>> + u32 dout; /* 0x10608 */
>>> + u32 din; /* 0x1060c */
>>> +};
>>> +
>>> +struct mvebu_spi_platdata {
>>> + struct spi_reg *spireg;
>>> + unsigned int frequency;
>>> + unsigned int clock;
>>> +};
>>> +
>>> +static void spi_cs_activate(struct spi_reg *reg, int cs)
>>> +{
>>> + setbits_le32(®->ctrl, MVEBU_SPI_A3700_SPI_EN_0 << cs);
>>> +}
>>> +
>>> +static void spi_cs_deactivate(struct spi_reg *reg, int cs)
>>> +{
>>> + clrbits_le32(®->ctrl, MVEBU_SPI_A3700_SPI_EN_0 << cs);
>>> +}
>>> +
>>> +/**
>>> + * spi_legacy_shift_byte() - triggers the real SPI transfer
>>> + * @bytelen: Indicate how many bytes to transfer.
>>> + * @dout: Buffer address of what to send.
>>> + * @din: Buffer address of where to receive.
>>> + *
>>> + * This function triggers the real SPI transfer in legacy mode. It
>>> + * will shift out char buffer from @dout, and shift in char buffer to
>>> + * @din, if necessary.
>>> + *
>>> + * This function assumes that only one byte is shifted at one time.
>>> + * However, it is not its responisbility to set the transfer type to
>>> + * one-byte. Also, it does not guarantee that it will work if transfer
>>> + * type becomes two-byte. See spi_set_legacy() for details.
>>> + *
>>> + * In legacy mode, simply write to the SPI_DOUT register will trigger
>>> + * the transfer.
>>> + *
>>> + * If @dout == NULL, which means no actual data needs to be sent out,
>>> + * then the function will shift out 0x00 in order to shift in data.
>>> + * The XFER_RDY flag is checked every time before accessing SPI_DOUT
>>> + * and SPI_DIN register.
>>> + *
>>> + * The number of transfers to be triggerred is decided by @bytelen.
>>> + *
>>> + * Return: 0 - cool
>>> + * -ETIMEDOUT - XFER_RDY flag timeout
>>> + */
>>> +static int spi_legacy_shift_byte(struct spi_reg *reg, unsigned int
>>> bytelen,
>>> + const void *dout, void *din)
>>> +{
>>> + const u8 *dout_8;
>>> + u8 *din_8;
>>> + int ret;
>>> +
>>> + /* Use 0x00 as dummy dout */
>>> + const u8 dummy_dout = 0x0;
>>> + u32 pending_dout = 0x0;
>>> +
>>> + /* dout_8: pointer of current dout */
>>> + dout_8 = dout;
>>> + /* din_8: pointer of current din */
>>> + din_8 = din;
>>> +
>>> + while (bytelen) {
>>> + ret = wait_for_bit(__func__, ®->ctrl,
>>> + MVEBU_SPI_A3700_XFER_RDY, true, 100,
>>> false);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + if (dout)
>>> + pending_dout = (u32)*dout_8;
>>> + else
>>> + pending_dout = (u32)dummy_dout;
>>> +
>>> + /* Trigger the xfer */
>>> + writel(pending_dout, ®->dout);
>>> +
>>> + if (din) {
>>> + ret = wait_for_bit(__func__, ®->ctrl,
>>> + MVEBU_SPI_A3700_XFER_RDY,
>>> + true, 100, false);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + /* Read what is transferred in */
>>> + *din_8 = (u8)readl(®->din);
>>> + }
>>> +
>>> + /* Don't increment the current pointer if NULL */
>>> + if (dout)
>>> + dout_8++;
>>> + if (din)
>>> + din_8++;
>>> +
>>> + bytelen--;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int mvebu_spi_xfer(struct udevice *dev, unsigned int bitlen,
>>> + const void *dout, void *din, unsigned long
>>> flags)
>>> +{
>>> + struct udevice *bus = dev->parent;
>>> + struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
>>> + struct spi_reg *reg = plat->spireg;
>>> + unsigned int bytelen;
>>> + int ret;
>>> +
>>> + bytelen = bitlen / 8;
>>> +
>>> + if (dout && din)
>>> + debug("This is a duplex transfer.\n");
>>> +
>>> + /* Activate CS */
>>> + if (flags & SPI_XFER_BEGIN) {
>>> + debug("SPI: activate cs.\n");
>>> + spi_cs_activate(reg, spi_chip_select(dev));
>>> + }
>>> +
>>> + /* Send and/or receive */
>>> + if (dout || din) {
>>> + ret = spi_legacy_shift_byte(reg, bytelen, dout, din);
>>> + if (ret)
>>> + return ret;
>>> + }
>>> +
>>> + /* Deactivate CS */
>>> + if (flags & SPI_XFER_END) {
>>> + ret = wait_for_bit(__func__, ®->ctrl,
>>> + MVEBU_SPI_A3700_XFER_RDY, true, 100,
>>> false);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + debug("SPI: deactivate cs.\n");
>>> + spi_cs_deactivate(reg, spi_chip_select(dev));
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int mvebu_spi_set_speed(struct udevice *bus, uint hz)
>>> +{
>>> + struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
>>> + struct spi_reg *reg = plat->spireg;
>>> + u32 data;
>>> +
>>> + data = readl(®->cfg);
>>> +
>>> + /* Set Prescaler */
>>> + data &= ~MVEBU_SPI_A3700_CLK_PRESCALE_MASK;
>>> +
>>> + /* Calculate Prescaler = (spi_input_freq / spi_max_freq) */
>>> + if (hz > plat->frequency)
>>> + hz = plat->frequency;
>>> + data |= plat->clock / plat->frequency;
>>
>>
>> Need to use the hz to compute here.
>
>
> Yes, hz should be used instead of plat->frequency here. Will fix
> in v3. Thanks for noticing.
>
>
>>> +
>>> + writel(data, ®->cfg);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int mvebu_spi_set_mode(struct udevice *bus, uint mode)
>>> +{
>>> + struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
>>> + struct spi_reg *reg = plat->spireg;
>>> +
>>> + /*
>>> + * Set SPI polarity
>>> + * 0: Serial interface clock is low when inactive
>>> + * 1: Serial interface clock is high when inactive
>>> + */
>>> + if (mode & SPI_CPOL)
>>> + setbits_le32(®->cfg, MVEBU_SPI_A3700_CLK_POL);
>>> + else
>>> + clrbits_le32(®->cfg, MVEBU_SPI_A3700_CLK_POL);
>>> + if (mode & SPI_CPHA)
>>> + setbits_le32(®->cfg, MVEBU_SPI_A3700_CLK_PHA);
>>> + else
>>> + clrbits_le32(®->cfg, MVEBU_SPI_A3700_CLK_PHA);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int mvebu_spi_probe(struct udevice *bus)
>>> +{
>>> + struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
>>> + struct spi_reg *reg = plat->spireg;
>>> + u32 data;
>>> + int ret;
>>> +
>>> + /*
>>> + * Settings SPI controller to be working in legacy mode, which
>>> + * means use only DO pin (I/O 1) for Data Out, and DI pin (I/O 0)
>>> + * for Data In.
>>> + */
>>> +
>>> + /* Flush read/write FIFO */
>>> + data = readl(®->cfg);
>>> + writel(data | MVEBU_SPI_A3700_FIFO_FLUSH, ®->cfg);
>>> + ret = wait_for_bit(__func__, ®->cfg,
>>> MVEBU_SPI_A3700_FIFO_FLUSH,
>>> + false, 1000, false);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + /* Disable FIFO mode */
>>> + data &= ~MVEBU_SPI_A3700_FIFO_EN;
>>> +
>>> + /* Always shift 1 byte at a time */
>>> + data &= ~MVEBU_SPI_A3700_BYTE_LEN;
>>> +
>>> + writel(data, ®->cfg);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int mvebu_spi_ofdata_to_platdata(struct udevice *bus)
>>> +{
>>> + struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
>>> +
>>> + plat->spireg = (struct spi_reg *)dev_get_addr(bus);
>>> +
>>> + plat->clock = fdtdec_get_int(gd->fdt_blob, bus->of_offset,
>>> + "clock-frequency", 160000);
>>
>>
>> I think this is not related to spi, global clock is it? usually we
>> can't use clock-frequency we set the clock with the help of
>> spi-max-frequency.
>
>
> This is the input clock to the SPI IP core in the SoC. And
> in most drivers I've seen so far, this frequency is configured
> via some macros / defines. E.g.:
>
> CONFIG_SYS_TCLK
> CONFIG_CQSPI_REF_CLK
> ...
>
> Best would be if this SPI input clock could be read via some
> clock driver infrastructure. But this is something that we
> don't have for MVEBU in U-Boot yet. So I can either switch back
> to some define for this value here or leave it as the DT property
> for now.
OK, use the dt and add FIXME with some proper comment.
thanks!
--
Jagan Teki
Free Software Engineer | www.openedev.com
U-Boot, Linux | Upstream Maintainer
Hyderabad, India.
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