[U-Boot] [PATCH v10] dm: at91: Add driver model support for the spi driver
Wenyou.Yang at microchip.com
Wenyou.Yang at microchip.com
Wed Oct 19 08:14:43 CEST 2016
Hi Jagan,
I am sorry for late answer.
> -----Original Message-----
> From: U-Boot [mailto:u-boot-bounces at lists.denx.de] On Behalf Of Jagan Teki
> Sent: 2016年9月21日 16:24
> To: Wenyou Yang <wenyou.yang at atmel.com>
> Cc: U-Boot Mailing List <u-boot at lists.denx.de>; Stephen Warren
> <swarren at nvidia.com>
> Subject: Re: [U-Boot] [PATCH v10] dm: at91: Add driver model support for the spi
> driver
>
> On Sun, Sep 18, 2016 at 12:28 PM, Wenyou Yang <wenyou.yang at atmel.com>
> wrote:
> > Add driver model support while retaining the existing legacy code.
> > This allows the driver to support boards that have converted to driver
> > model as well as those that have not.
> >
> > Signed-off-by: Wenyou Yang <wenyou.yang at atmel.com>
> > Reviewed-by: Simon Glass <sjg at chromium.org>
> > Acked-by: Stephen Warren <swarren at nvidia.com>
> > ---
> >
> > Changes in v10:
> > - Add Acked-by tag.
> >
> > Changes in v9:
> > - Due to the peripheral clock driver improvement, remove the
> > unneccessary clock calling.
> >
> > Changes in v8:
> > - Fix compile error for AVR32.
> >
> > Changes in v7:
> > - Move gpio_request_list_by_name() to _probe(), remove
> > *_ofdata_to_platdata().
> >
> > Changes in v6:
> > - Remove the two flash related options.
> >
> > Changes in v5:
> > - Change clk_client.h -> clk.h to adapt to clk API conversion.
> >
> > Changes in v4:
> > - Collect Reviewed-by tag.
> > - Update the clk API based on [PATCH] clk: convert API to match
> > reset/mailbox fstyle (http://patchwork.ozlabs.org/patch/625342/).
> > - Remove check on dev_get_parent() return.
> > - Fixed the return value, -ENODEV->-EINVAL.
> > - Retain #include <asm/arch/clk.h> line.
> >
> > Changes in v3:
> > - Remove redundant log print.
> >
> > Changes in v2:
> > - Add clock support.
> >
> > drivers/spi/Kconfig | 7 ++
> > drivers/spi/atmel_spi.c | 283
> > ++++++++++++++++++++++++++++++++++++++++++++++++
> > 2 files changed, 290 insertions(+)
> >
> > diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index
> > aca385d..16ed231 100644
> > --- a/drivers/spi/Kconfig
> > +++ b/drivers/spi/Kconfig
> > @@ -32,6 +32,13 @@ config ATH79_SPI
> > uses driver model and requires a device tree binding to operate.
> > please refer to doc/device-tree-bindings/spi/spi-ath79.txt.
> >
> > +config ATMEL_SPI
> > + bool "Atmel SPI driver"
> > + depends on ARCH_AT91
> > + help
> > + Enable the Atmel SPI driver. This driver can be used to access
> > + the SPI Flash, such as AT25DF321.
> > +
> > config CADENCE_QSPI
> > bool "Cadence QSPI driver"
> > help
> > diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c index
> > ed6278b..190f58b 100644
> > --- a/drivers/spi/atmel_spi.c
> > +++ b/drivers/spi/atmel_spi.c
> > @@ -4,6 +4,9 @@
> > * SPDX-License-Identifier: GPL-2.0+
> > */
> > #include <common.h>
> > +#include <clk.h>
> > +#include <dm.h>
> > +#include <fdtdec.h>
> > #include <spi.h>
> > #include <malloc.h>
> >
> > @@ -11,9 +14,19 @@
> >
> > #include <asm/arch/clk.h>
> > #include <asm/arch/hardware.h>
> > +#ifdef CONFIG_DM_SPI
> > +#include <asm/arch/at91_spi.h>
> > +#endif
> > +#ifdef CONFIG_DM_GPIO
> > +#include <asm/gpio.h>
> > +#endif
> >
> > #include "atmel_spi.h"
> >
> > +DECLARE_GLOBAL_DATA_PTR;
> > +
> > +#ifndef CONFIG_DM_SPI
> > +
> > static int spi_has_wdrbt(struct atmel_spi_slave *slave) {
> > unsigned int ver;
> > @@ -209,3 +222,273 @@ out:
> >
> > return 0;
> > }
> > +
> > +#else
> > +
> > +#define MAX_CS_COUNT 4
> > +
> > +struct atmel_spi_platdata {
> > + struct at91_spi *regs;
> > +};
> > +
> > +struct atmel_spi_priv {
> > + unsigned int freq; /* Default frequency */
> > + unsigned int mode;
> > + ulong bus_clk_rate;
> > + struct gpio_desc cs_gpios[MAX_CS_COUNT]; };
> > +
> > +static int atmel_spi_claim_bus(struct udevice *dev) {
> > + struct udevice *bus = dev_get_parent(dev);
> > + struct atmel_spi_platdata *bus_plat = dev_get_platdata(bus);
> > + struct atmel_spi_priv *priv = dev_get_priv(bus);
> > + struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
> > + struct at91_spi *reg_base = bus_plat->regs;
> > + u32 cs = slave_plat->cs;
> > + u32 freq = priv->freq;
> > + u32 scbr, csrx, mode;
> > +
> > + scbr = (priv->bus_clk_rate + freq - 1) / freq;
> > + if (scbr > ATMEL_SPI_CSRx_SCBR_MAX)
> > + return -EINVAL;
> > +
> > + if (scbr < 1)
> > + scbr = 1;
> > +
> > + csrx = ATMEL_SPI_CSRx_SCBR(scbr);
> > + csrx |= ATMEL_SPI_CSRx_BITS(ATMEL_SPI_BITS_8);
> > +
> > + if (!(priv->mode & SPI_CPHA))
> > + csrx |= ATMEL_SPI_CSRx_NCPHA;
> > + if (priv->mode & SPI_CPOL)
> > + csrx |= ATMEL_SPI_CSRx_CPOL;
> > +
> > + writel(csrx, ®_base->csr[cs]);
> > +
> > + mode = ATMEL_SPI_MR_MSTR |
> > + ATMEL_SPI_MR_MODFDIS |
> > + ATMEL_SPI_MR_WDRBT |
> > + ATMEL_SPI_MR_PCS(~(1 << cs));
> > +
> > + writel(mode, ®_base->mr);
>
> Usually this mode and speed stuff should go on respetcive fops. Since we couldn't
> find the cs number on those fops you wrote these here, correct? can you tried to
> add .cs_info see we can get the cs number so-that these will move, becuase
> claim bus usually enable the spi instead of doing mode and speed stuff.
>
I looked through the code, try to add .cs_info as your advice.
But failed.
Could you give me more information? Thank you.
> > +
> > + writel(ATMEL_SPI_CR_SPIEN, ®_base->cr);
>
> This is correct.
>
> > +
> > + return 0;
> > +}
> > +
> > +static int atmel_spi_release_bus(struct udevice *dev) {
> > + struct udevice *bus = dev_get_parent(dev);
> > + struct atmel_spi_platdata *bus_plat = dev_get_platdata(bus);
> > +
> > + writel(ATMEL_SPI_CR_SPIDIS, &bus_plat->regs->cr);
> > +
> > + return 0;
> > +}
> > +
> > +static void atmel_spi_cs_activate(struct udevice *dev) {
> > + struct udevice *bus = dev_get_parent(dev);
> > + struct atmel_spi_priv *priv = dev_get_priv(bus);
> > + struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
> > + u32 cs = slave_plat->cs;
> > +
> > + dm_gpio_set_value(&priv->cs_gpios[cs], 0); }
> > +
> > +static void atmel_spi_cs_deactivate(struct udevice *dev) {
> > + struct udevice *bus = dev_get_parent(dev);
> > + struct atmel_spi_priv *priv = dev_get_priv(bus);
> > + struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
> > + u32 cs = slave_plat->cs;
> > +
> > + dm_gpio_set_value(&priv->cs_gpios[cs], 1); }
> > +
> > +static int atmel_spi_xfer(struct udevice *dev, unsigned int bitlen,
> > + const void *dout, void *din, unsigned long
> > +flags) {
> > + struct udevice *bus = dev_get_parent(dev);
> > + struct atmel_spi_platdata *bus_plat = dev_get_platdata(bus);
> > + struct at91_spi *reg_base = bus_plat->regs;
> > +
> > + u32 len_tx, len_rx, len;
> > + u32 status;
> > + const u8 *txp = dout;
> > + u8 *rxp = din;
> > + u8 value;
> > +
> > + if (bitlen == 0)
> > + goto out;
> > +
> > + /*
> > + * The controller can do non-multiple-of-8 bit
> > + * transfers, but this driver currently doesn't support it.
> > + *
> > + * It's also not clear how such transfers are supposed to be
> > + * represented as a stream of bytes...this is a limitation of
> > + * the current SPI interface.
> > + */
> > + if (bitlen % 8) {
> > + /* Errors always terminate an ongoing transfer */
> > + flags |= SPI_XFER_END;
> > + goto out;
> > + }
> > +
> > + len = bitlen / 8;
> > +
> > + /*
> > + * The controller can do automatic CS control, but it is
> > + * somewhat quirky, and it doesn't really buy us much anyway
> > + * in the context of U-Boot.
> > + */
> > + if (flags & SPI_XFER_BEGIN) {
> > + atmel_spi_cs_activate(dev);
> > +
> > + /*
> > + * sometimes the RDR is not empty when we get here,
> > + * in theory that should not happen, but it DOES happen.
> > + * Read it here to be on the safe side.
> > + * That also clears the OVRES flag. Required if the
> > + * following loop exits due to OVRES!
> > + */
> > + readl(®_base->rdr);
> > + }
> > +
> > + for (len_tx = 0, len_rx = 0; len_rx < len; ) {
> > + status = readl(®_base->sr);
> > +
> > + if (status & ATMEL_SPI_SR_OVRES)
> > + return -1;
> > +
> > + if ((len_tx < len) && (status & ATMEL_SPI_SR_TDRE)) {
> > + if (txp)
> > + value = *txp++;
> > + else
> > + value = 0;
> > + writel(value, ®_base->tdr);
> > + len_tx++;
> > + }
> > +
> > + if (status & ATMEL_SPI_SR_RDRF) {
> > + value = readl(®_base->rdr);
> > + if (rxp)
> > + *rxp++ = value;
> > + len_rx++;
> > + }
> > + }
> > +
> > +out:
> > + if (flags & SPI_XFER_END) {
> > + /*
> > + * Wait until the transfer is completely done before
> > + * we deactivate CS.
> > + */
> > + do {
> > + status = readl(®_base->sr);
> > + } while (!(status & ATMEL_SPI_SR_TXEMPTY));
>
> Use wait_for_bit.
Accepted.
Best Regards,
Wenyou Yang
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