[U-Boot] [PATCH v10] dm: at91: Add driver model support for the spi driver
Jagan Teki
jagannadh.teki at gmail.com
Wed Sep 21 10:23:55 CEST 2016
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.
> +
> + 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.
thanks!
--
Jagan Teki
Free Software Engineer | www.openedev.com
U-Boot, Linux | Upstream Maintainer
Hyderabad, India.
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