[U-Boot] [PATCH v6] dm: at91: Add driver model support for the spi driver
Jagan Teki
jagannadh.teki at gmail.com
Tue Jul 26 08:21:26 CEST 2016
On 25 July 2016 at 15:27, 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>
> ---
>
> 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 | 303 ++++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 310 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..98bee35 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 +14,15 @@
>
> #include <asm/arch/clk.h>
> #include <asm/arch/hardware.h>
> +#include <asm/arch/at91_spi.h>
> +#include <asm/gpio.h>
>
> #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 +218,297 @@ 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);
> +
> + writel(ATMEL_SPI_CR_SPIEN, ®_base->cr);
> +
> + 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));
> +
> + atmel_spi_cs_deactivate(dev);
> + }
> +
> + return 0;
> +}
> +
> +static int atmel_spi_set_speed(struct udevice *bus, uint speed)
> +{
> + struct atmel_spi_priv *priv = dev_get_priv(bus);
> +
> + priv->freq = speed;
> +
> + return 0;
> +}
> +
> +static int atmel_spi_set_mode(struct udevice *bus, uint mode)
> +{
> + struct atmel_spi_priv *priv = dev_get_priv(bus);
> +
> + priv->mode = mode;
> +
> + return 0;
> +}
> +
> +static const struct dm_spi_ops atmel_spi_ops = {
> + .claim_bus = atmel_spi_claim_bus,
> + .release_bus = atmel_spi_release_bus,
> + .xfer = atmel_spi_xfer,
> + .set_speed = atmel_spi_set_speed,
> + .set_mode = atmel_spi_set_mode,
> + /*
> + * cs_info is not needed, since we require all chip selects to be
> + * in the device tree explicitly
> + */
> +};
> +
> +static int atmel_spi_ofdata_to_platdata(struct udevice *bus)
> +{
> + struct atmel_spi_priv *priv = dev_get_priv(bus);
> + int ret;
> +
> + ret = gpio_request_list_by_name(bus, "cs-gpios", priv->cs_gpios,
> + ARRAY_SIZE(priv->cs_gpios), 0);
> + if (ret < 0) {
> + error("Can't get %s gpios! Error: %d", bus->name, ret);
> + return ret;
> + }
> +
> + return 0;
> +}
Better to use plat->cs_gpio or do this gpio_request in probe because
*_ofdata_to_platdata usually assign/get the plat data.
> +
> +static int atmel_spi_enable_clk(struct udevice *bus)
> +{
> + struct atmel_spi_priv *priv = dev_get_priv(bus);
> + struct udevice *dev_clk;
> + struct clk clk;
> + ulong clk_rate;
> + int periph;
> + int ret;
> +
> + ret = clk_get_by_index(bus, 0, &clk);
> + if (ret)
> + return -EINVAL;
> +
> + periph = fdtdec_get_uint(gd->fdt_blob, clk.dev->of_offset, "reg", -1);
> + if (periph < 0)
> + return -EINVAL;
> +
> + dev_clk = dev_get_parent(clk.dev);
> + ret = clk_request(dev_clk, &clk);
> + if (ret)
> + return ret;
> +
> + clk.id = periph;
> + ret = clk_enable(&clk);
> + if (ret)
> + return ret;
> +
> + ret = clk_get_by_index(dev_clk, 0, &clk);
> + if (ret)
> + return ret;
> +
> + clk_rate = clk_get_rate(&clk);
> + if (!clk_rate)
> + return -EINVAL;
> +
> + priv->bus_clk_rate = clk_rate;
> +
> + clk_free(&clk);
> +
> + return 0;
> +}
> +
> +static int atmel_spi_probe(struct udevice *bus)
> +{
> + struct atmel_spi_platdata *bus_plat = dev_get_platdata(bus);
> + int ret;
> +
> + ret = atmel_spi_enable_clk(bus);
> + if (ret)
> + return ret;
> +
> + bus_plat->regs = (struct at91_spi *)dev_get_addr(bus);
> +
> + writel(ATMEL_SPI_CR_SWRST, &bus_plat->regs->cr);
> +
> + return 0;
> +}
Same comment as above, doing opposite.
thanks!
--
Jagan.
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