native cs and gpio cs in spi - imx6

[surendradhobale]

Hello,

         We are using four ecspi from imx6ul.When i used cs as gpio then everything works fine.

But when i used CS as native. It wont work.

Following configuration i have done for native CS in dts as,

&ecspi1 {
 fsl,spi-num-chipselects = <1>;
 cs-gpios = <0>;
 pinctrl-names = "default";
  pinctrl-0 = <&pinctrl_ecspi1 &pinctrl_spi_cs1>;
 status = "okay";

  spi1_max14830: max14830@0 {
                   compatible = "maxim,max14830";
                   reg = <0>;
                    mode = <0>;
                   clocks = <&clk10m>;
                   clock-names = "osc";
                     interrupt-parent = <&gpio4>;
                    interrupts = <10 IRQ_TYPE_EDGE_FALLING >;
                         gpio-controller;
                       #gpio-cells = <2>;
                   spi-max-frequency = <10000000>;
 };
};

Pin Mux

pinctrl_ecspi1: ecspi1grp {
   fsl,pins = <
    MX6UL_PAD_CSI_DATA04__ECSPI1_SCLK 0x10a0
    /* MX6UL_PAD_CSI_DATA05__ECSPI1_SS0 0x10b0 */
    /* MX6UL_PAD_CSI_DATA05__GPIO4_IO26 0x10a0 */
    MX6UL_PAD_CSI_DATA06__ECSPI1_MOSI 0x10a0
    MX6UL_PAD_CSI_DATA07__ECSPI1_MISO 0x10a0
    MX6UL_PAD_NAND_ALE__GPIO4_IO10  0x10a0
   >;
  };

 pinctrl_spi_cs1: spi_cs1 {
   fsl,pins = <
    MX6UL_PAD_CSI_DATA05__ECSPI1_SS0 0x10b0
   >;
  };

When I configure same interface with CS as gpio

cs-gpios = <&gpio4 26 GPIO_ACTIVE_LOW>;

It works fine.

Why it doesnot work with native cs?

I am using the Kernel 4.9 and spi-imx driver. Can you please help me in this issue.

Regards,

Surendra

[fabio_estevam · Accepted solution]

Hi Surendra,

Natve chip select usage on spi-imx driver has been fixed commit 602c8f4485cd1e6de67e41c78db96fa4f6808e53
Author: Greg Ungerer <gerg@linux-m68k.org>
Date:   Tue Jul 11 14:22:11 2017 +1000

    spi: imx: fix use of native chip-selects with devicetree

from 4.14 kernel.

So you could either use GPIO chip select or backport this fix into 4.9.

Regards,

Fabio Estevam

[surendradhobale]

Hello Fabio,

I am using the imx6ul. In spi-imx driver configuration is under mx51_ecspi_config.

The patch you mentioned is only for the mx31_config and mx21_config. So this patch not applicable to mx51 ecspi configuration.

Thanks,

Surendra

[igorpadykov]

Hi Surendra

please try below patch

kernel/git/next/linux-next.git - The linux-next integration testing tree 

Best regards
igor
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[surendradhobale]

Hello igor,

      Thanks for quick reply . I have applied same patch. But same result.

Same results. ( when i configure cs-gpio = <0> and with this patch). When i debuggging the code spi->chip_select is configured, but doesnot reading the correct data ( like REV ID) from the slave device.

The functionality of the spi-imx driver working fine with native CS?

Thanks & Regards,

Surendra

[igorpadykov]

Hi Surendra

please post this on kernel mail list,

Majordomo Lists at VGER.KERNEL.ORG 

nxp bsp does not support native CS.

Best regards
igor

[surendradhobale]

Hello Igor,

 I am using NXP repository kernel 4.9 

This does not have native CS support'?

Means I can use only GPIO Chip select ?