From: Jean-Michel Hautbois <jhautbois@gmail.com> To: boris.brezillon@bootlin.com Cc: linux-arm-kernel@lists.infradead.org, linux-kernel <linux-kernel@vger.kernel.org>, Nicolas Ferre <nicolas.ferre@atmel.com> Subject: sama5d: using the ebi interface from another driver Date: Fri, 2 Nov 2018 14:35:26 +0100 [thread overview] Message-ID: <CAL8zT=imudTXvbsxx42mPSQj7Qt1b=44wnPHpb09-sOqLewu-w@mail.gmail.com> (raw) Hi all, I have a custom board based on a sama5d3 chip. The SoC is connected to 2 pef24628 SHDSL transceivers, the first one on ebi@40000000 and the second one on ebi@50000000. I tried to write a basic char driver, using request_mem_region and ioremap but I can't read or write into the device. I have to say that the driver is based on a proprietary one, and tested years ago on a PowerPC board. Then, after looking into deeper details in the datasheet I understand it is connected through EBI and it sounds not so easy :D. I would appreciate some help/pointers on this, as there is (at least, I could find) few documentation on how to use it except for NAND cases. I have something like that in my DTS, but not sure this is the correct way to do it : ebi: ebi@10000000 { pinctrl-0 = <&pinctrl_ebi_nand_addr>; pinctrl-names = "default"; status = "okay"; dsp0: pef24628@1 { status = "okay"; compatible = "intel,pef24628"; #address-cells = <1>; #size-cells = <1>; reg = <0x1 0x0 0x8000>; pinctrl-0 = <&pinctrl_dsp_cs1>; }; dsp1: pef24628@2 { status = "okay"; compatible = "intel,pef24628"; #address-cells = <1>; #size-cells = <1>; reg = <0x2 0x0 0x8000>; pinctrl-0 = <&pinctrl_dsp_cs2>; }; nand_controller: nand-controller { status = "okay"; nand@3 { reg = <0x3 0x0 0x2>; atmel,rb = <0>; nand-bus-width = <8>; nand-ecc-mode = "hw"; nand-ecc-strength = <4>; nand-ecc-step-size = <512>; nand-on-flash-bbt; label = "atmel_nand"; partitions { compatible = "fixed-partitions"; #address-cells = <1>; #size-cells = <1>; [...] }; }; }; The pinctrl for ebi should probably be changed however, I am wondering how the (platform ?) driver can access the adress ? Should it parse itself the parent, and find range, etc. Or is there an accessor for it ? Maybe can I just manually toggle the CS GPIO, and don't try to make anything more complex than what it should be ? The driver should not be atmel dependant... Thanks ! JM
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From: jhautbois@gmail.com (Jean-Michel Hautbois) To: linux-arm-kernel@lists.infradead.org Subject: sama5d: using the ebi interface from another driver Date: Fri, 2 Nov 2018 14:35:26 +0100 [thread overview] Message-ID: <CAL8zT=imudTXvbsxx42mPSQj7Qt1b=44wnPHpb09-sOqLewu-w@mail.gmail.com> (raw) Hi all, I have a custom board based on a sama5d3 chip. The SoC is connected to 2 pef24628 SHDSL transceivers, the first one on ebi at 40000000 and the second one on ebi at 50000000. I tried to write a basic char driver, using request_mem_region and ioremap but I can't read or write into the device. I have to say that the driver is based on a proprietary one, and tested years ago on a PowerPC board. Then, after looking into deeper details in the datasheet I understand it is connected through EBI and it sounds not so easy :D. I would appreciate some help/pointers on this, as there is (at least, I could find) few documentation on how to use it except for NAND cases. I have something like that in my DTS, but not sure this is the correct way to do it : ebi: ebi at 10000000 { pinctrl-0 = <&pinctrl_ebi_nand_addr>; pinctrl-names = "default"; status = "okay"; dsp0: pef24628 at 1 { status = "okay"; compatible = "intel,pef24628"; #address-cells = <1>; #size-cells = <1>; reg = <0x1 0x0 0x8000>; pinctrl-0 = <&pinctrl_dsp_cs1>; }; dsp1: pef24628 at 2 { status = "okay"; compatible = "intel,pef24628"; #address-cells = <1>; #size-cells = <1>; reg = <0x2 0x0 0x8000>; pinctrl-0 = <&pinctrl_dsp_cs2>; }; nand_controller: nand-controller { status = "okay"; nand at 3 { reg = <0x3 0x0 0x2>; atmel,rb = <0>; nand-bus-width = <8>; nand-ecc-mode = "hw"; nand-ecc-strength = <4>; nand-ecc-step-size = <512>; nand-on-flash-bbt; label = "atmel_nand"; partitions { compatible = "fixed-partitions"; #address-cells = <1>; #size-cells = <1>; [...] }; }; }; The pinctrl for ebi should probably be changed however, I am wondering how the (platform ?) driver can access the adress ? Should it parse itself the parent, and find range, etc. Or is there an accessor for it ? Maybe can I just manually toggle the CS GPIO, and don't try to make anything more complex than what it should be ? The driver should not be atmel dependant... Thanks ! JM
next reply other threads:[~2018-11-02 13:34 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-11-02 13:35 Jean-Michel Hautbois [this message] 2018-11-02 13:35 ` sama5d: using the ebi interface from another driver Jean-Michel Hautbois 2018-11-05 9:19 ` Ludovic Desroches 2018-11-05 9:19 ` Ludovic Desroches 2018-11-06 9:57 ` Alexander Dahl 2018-11-06 9:57 ` Alexander Dahl 2018-11-07 17:07 ` Jean-Michel Hautbois 2018-11-07 17:07 ` Jean-Michel Hautbois
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