Re: [PATCH] spi: orion: Add multiple chip select support for Armada 370 and 375

From: Gregory CLEMENT
Date: Tue Jan 06 2015 - 17:01:17 EST

Hi Ken,

On 06/01/2015 22:30, Ken Wilson wrote:
> Create a new dt binding for the Armada 375 that supports up to
> 3 chip selects but uses the same prescaler values and algorithm
> as the basic orion binding.

There was already a patch that have been sent for this:
http://thread.gmane.org/gmane.linux.kernel.spi.devel/17808/focus=17809

but in the end it has not been merged. The last email on the thread was
about doing the manipulation in set_cs and not in setup_transfer(). And I
didn't find a newer version.

Maybe it just fell through the cracks.
Thomas did you remember of it?

Gregory

>
> Update the Armada 370 so that it supports up to 4 chip selects.
>
> This has been tested on the Armada 375 with multiple SPI-NOR chips.
>
> Signed-off-by: Ken Wilson <ken.wilson@xxxxxxxxxxxx>
> ---
> .../devicetree/bindings/spi/spi-orion.txt | 3 ++-
> arch/arm/boot/dts/armada-375.dtsi | 4 +--
> drivers/spi/spi-orion.c | 29 +++++++++++++++++++---
> 3 files changed, 29 insertions(+), 7 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/spi/spi-orion.txt b/Documentation/devicetree/bindings/spi/spi-orion.txt
> index 50c3a3d..2aeeb85 100644
> --- a/Documentation/devicetree/bindings/spi/spi-orion.txt
> +++ b/Documentation/devicetree/bindings/spi/spi-orion.txt
> @@ -1,7 +1,8 @@
> Marvell Orion SPI device
>
> Required properties:
> -- compatible : should be "marvell,orion-spi" or "marvell,armada-370-spi".
> +- compatible : should be "marvell,orion-spi", "marvell,armada-370-spi",
> + or "marvell,armada-375-spi".
> - reg : offset and length of the register set for the device
> - cell-index : Which of multiple SPI controllers is this.
> Optional properties:
> diff --git a/arch/arm/boot/dts/armada-375.dtsi b/arch/arm/boot/dts/armada-375.dtsi
> index de65714..f7a5ce2 100644
> --- a/arch/arm/boot/dts/armada-375.dtsi
> +++ b/arch/arm/boot/dts/armada-375.dtsi
> @@ -192,7 +192,7 @@
> };
>
> spi0: spi@10600 {
> - compatible = "marvell,orion-spi";
> + compatible = "marvell,armada-375-spi", "marvell,orion-spi";
> reg = <0x10600 0x50>;
> #address-cells = <1>;
> #size-cells = <0>;
> @@ -203,7 +203,7 @@
> };
>
> spi1: spi@10680 {
> - compatible = "marvell,orion-spi";
> + compatible = "marvell,armada-375-spi", "marvell,orion-spi";
> reg = <0x10680 0x50>;
> #address-cells = <1>;
> #size-cells = <0>;
> diff --git a/drivers/spi/spi-orion.c b/drivers/spi/spi-orion.c
> index c76b7d7..4129c37 100644
> --- a/drivers/spi/spi-orion.c
> +++ b/drivers/spi/spi-orion.c
> @@ -28,7 +28,6 @@
> /* Runtime PM autosuspend timeout: PM is fairly light on this driver */
> #define SPI_AUTOSUSPEND_TIMEOUT 200
>
> -#define ORION_NUM_CHIPSELECTS 1 /* only one slave is supported*/
> #define ORION_SPI_WAIT_RDY_MAX_LOOP 2000 /* in usec */
>
> #define ORION_SPI_IF_CTRL_REG 0x00
> @@ -44,6 +43,7 @@
> #define ARMADA_SPI_CLK_PRESCALE_MASK 0xDF
> #define ORION_SPI_MODE_MASK (ORION_SPI_MODE_CPOL | \
> ORION_SPI_MODE_CPHA)
> +#define ORION_SPI_CS_MASK 0x1C
>
> enum orion_spi_type {
> ORION_SPI,
> @@ -55,6 +55,7 @@ struct orion_spi_dev {
> unsigned int min_divisor;
> unsigned int max_divisor;
> u32 prescale_mask;
> + u8 num_cs;
> };
>
> struct orion_spi {
> @@ -201,6 +202,13 @@ orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
>
> orion_spi_mode_set(spi);
>
> + if (orion_spi->master->num_chipselect > 1) {
> + orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG,
> + ORION_SPI_CS_MASK);
> + orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG,
> + (spi->chip_select) << 2);
> + }
> +
> rc = orion_spi_baudrate_set(spi, speed);
> if (rc)
> return rc;
> @@ -398,18 +406,31 @@ static const struct orion_spi_dev orion_spi_dev_data = {
> .min_divisor = 4,
> .max_divisor = 30,
> .prescale_mask = ORION_SPI_CLK_PRESCALE_MASK,
> + .num_cs = 1,
> };
>
> -static const struct orion_spi_dev armada_spi_dev_data = {
> +static const struct orion_spi_dev armada_370_spi_dev_data = {
> .typ = ARMADA_SPI,
> .min_divisor = 1,
> .max_divisor = 1920,
> .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
> + .num_cs = 4,
> +};
> +
> +static const struct orion_spi_dev armada_375_spi_dev_data = {
> + .typ = ORION_SPI,
> + .min_divisor = 4,
> + .max_divisor = 30,
> + .prescale_mask = ORION_SPI_CLK_PRESCALE_MASK,
> + .num_cs = 3,
> };
>
> static const struct of_device_id orion_spi_of_match_table[] = {
> { .compatible = "marvell,orion-spi", .data = &orion_spi_dev_data, },
> - { .compatible = "marvell,armada-370-spi", .data = &armada_spi_dev_data, },
> + { .compatible = "marvell,armada-370-spi",
> + .data = &armada_370_spi_dev_data, },
> + { .compatible = "marvell,armada-375-spi",
> + .data = &armada_375_spi_dev_data, },
> {}
> };
> MODULE_DEVICE_TABLE(of, orion_spi_of_match_table);
> @@ -444,7 +465,6 @@ static int orion_spi_probe(struct platform_device *pdev)
> master->mode_bits = SPI_CPHA | SPI_CPOL;
>
> master->transfer_one_message = orion_spi_transfer_one_message;
> - master->num_chipselect = ORION_NUM_CHIPSELECTS;
> master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
> master->auto_runtime_pm = true;
>
> @@ -470,6 +490,7 @@ static int orion_spi_probe(struct platform_device *pdev)
> tclk_hz = clk_get_rate(spi->clk);
> master->max_speed_hz = DIV_ROUND_UP(tclk_hz, devdata->min_divisor);
> master->min_speed_hz = DIV_ROUND_UP(tclk_hz, devdata->max_divisor);
> + master->num_chipselect = devdata->num_cs;
>
> r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> spi->base = devm_ioremap_resource(&pdev->dev, r);
>


--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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