Commit 15f8c604 authored by Scott Wood's avatar Scott Wood Committed by Kumar Gala
Browse files

[POWERPC] cpm: Describe multi-user ram in its own device node. 



The way the current CPM binding describes available multi-user (a.k.a.
dual-ported) RAM doesn't work well when there are multiple free regions,
and it doesn't work at all if the region doesn't begin at the start of
the muram area (as the hardware needs to be programmed with offsets into
this area).  The latter situation can happen with SMC UARTs on CPM2, as its
parameter RAM is relocatable, u-boot puts it at zero, and the kernel doesn't
support moving it.

It is now described with a muram node, similar to QE.  The current CPM
binding is sufficiently recent (i.e. never appeared in an official release)
that compatibility with existing device trees is not an issue.

The code supporting the new binding is shared between cpm1 and cpm2, rather
than remain separated.  QE should be able to use this code as well, once
minor fixes are made to its device trees.

Signed-off-by: default avatarScott Wood <scottwood@freescale.com>
Signed-off-by: default avatarKumar Gala <galak@kernel.crashing.org>
parent 3c5df5c2

Documentation/powerpc/booting-without-of.txt

+36 −4
Original line number Diff line number Diff line
@@ -1861,9 +1861,7 @@ platforms are moved over to use the flattened-device-tree model. 


   Properties:

   - compatible : "fsl,cpm1", "fsl,cpm2", or "fsl,qe".

   - reg : The first resource is a 48-byte region beginning with

           CPCR.  The second is the available general-purpose

           DPRAM.

   - reg : A 48-byte region beginning with CPCR.



   Example:

	cpm@119c0 {
@@ -1871,7 +1869,7 @@ platforms are moved over to use the flattened-device-tree model. 
		#size-cells = <1>;

		#interrupt-cells = <2>;

		compatible = "fsl,mpc8272-cpm", "fsl,cpm2";

		reg = <119c0 30 0 2000>;

		reg = <119c0 30>;

	}



   ii) Properties common to mulitple CPM/QE devices
@@ -2017,6 +2015,40 @@ platforms are moved over to use the flattened-device-tree model. 
		fsl,cpm-command = <2e600000>;

	};



   viii) Multi-User RAM (MURAM)



   The multi-user/dual-ported RAM is expressed as a bus under the CPM node.



   Ranges must be set up subject to the following restrictions:



   - Children's reg nodes must be offsets from the start of all muram, even

     if the user-data area does not begin at zero.

   - If multiple range entries are used, the difference between the parent

     address and the child address must be the same in all, so that a single

     mapping can cover them all while maintaining the ability to determine

     CPM-side offsets with pointer subtraction.  It is recommended that

     multiple range entries not be used.

   - A child address of zero must be translatable, even if no reg resources

     contain it.



   A child "data" node must exist, compatible with "fsl,cpm-muram-data", to

   indicate the portion of muram that is usable by the OS for arbitrary

   purposes.  The data node may have an arbitrary number of reg resources,

   all of which contribute to the allocatable muram pool.



   Example, based on mpc8272:



	muram@0 {

		#address-cells = <1>;

		#size-cells = <1>;

		ranges = <0 0 10000>;



		data@0 {

			compatible = "fsl,cpm-muram-data";

			reg = <0 2000 9800 800>;

		};

	};



   m) Chipselect/Local Bus



   Properties:

arch/powerpc/Kconfig.debug

+3 −3
Original line number Diff line number Diff line
@@ -245,9 +245,9 @@ config PPC_EARLY_DEBUG_44x_PHYSHIGH 
config PPC_EARLY_DEBUG_CPM_ADDR

	hex "CPM UART early debug transmit descriptor address"

	depends on PPC_EARLY_DEBUG_CPM

	default "0xfa202808" if PPC_EP88XC

	default "0xf0000808" if CPM2

	default "0xff002808" if CPM1

	default "0xfa202008" if PPC_EP88XC

	default "0xf0000008" if CPM2

	default "0xff002008" if CPM1

	help

	  This specifies the address of the transmit descriptor

	  used for early debug output.  Because it is needed before

arch/powerpc/boot/cpm-serial.c

+32 −12
Original line number Diff line number Diff line
@@ -56,7 +56,8 @@ static struct cpm_smc *smc; 
static struct cpm_scc *scc;

struct cpm_bd *tbdf, *rbdf;

static u32 cpm_cmd;

static u8 *dpram_start;

static u8 *muram_start;

static u32 muram_offset;



static void (*do_cmd)(int op);

static void (*enable_port)(void);
@@ -114,13 +115,12 @@ static void scc_enable_port(void) 


static int cpm_serial_open(void)

{

	int dpaddr = 0x800;

	disable_port();



	out_8(&param->rfcr, 0x10);

	out_8(&param->tfcr, 0x10);



	rbdf = (struct cpm_bd *)(dpram_start + dpaddr);

	rbdf = (struct cpm_bd *)muram_start;

	rbdf->addr = (u8 *)(rbdf + 2);

	rbdf->sc = 0xa000;

	rbdf->len = 1;
@@ -131,8 +131,8 @@ static int cpm_serial_open(void) 
	tbdf->len = 1;



	sync();

	out_be16(&param->rbase, dpaddr);

	out_be16(&param->tbase, dpaddr + sizeof(struct cpm_bd));

	out_be16(&param->rbase, muram_offset);

	out_be16(&param->tbase, muram_offset + sizeof(struct cpm_bd));



	do_cmd(CPM_CMD_INIT_RX_TX);
@@ -178,7 +178,7 @@ int cpm_console_init(void *devp, struct serial_console_data *scdp) 
	void *reg_virt[2];

	int is_smc = 0, is_cpm2 = 0, n;

	unsigned long reg_phys;

	void *parent;

	void *parent, *muram;



	if (dt_is_compatible(devp, "fsl,cpm1-smc-uart")) {

		is_smc = 1;
@@ -229,16 +229,36 @@ int cpm_console_init(void *devp, struct serial_console_data *scdp) 


	n = getprop(parent, "virtual-reg", reg_virt, sizeof(reg_virt));

	if (n < (int)sizeof(reg_virt)) {

		for (n = 0; n < 2; n++) {

			if (!dt_xlate_reg(parent, n, &reg_phys, NULL))

		if (!dt_xlate_reg(parent, 0, &reg_phys, NULL))

			return -1;



			reg_virt[n] = (void *)reg_phys;

		}

		reg_virt[0] = (void *)reg_phys;

	}



	cpcr = reg_virt[0];

	dpram_start = reg_virt[1];



	muram = finddevice("/soc/cpm/muram/data");

	if (!muram)

		return -1;



	/* For bootwrapper-compatible device trees, we assume that the first

	 * entry has at least 18 bytes, and that #address-cells/#data-cells

	 * is one for both parent and child.

	 */



	n = getprop(muram, "virtual-reg", reg_virt, sizeof(reg_virt));

	if (n < (int)sizeof(reg_virt)) {

		if (!dt_xlate_reg(muram, 0, &reg_phys, NULL))

			return -1;



		reg_virt[0] = (void *)reg_phys;

	}



	muram_start = reg_virt[0];



	n = getprop(muram, "reg", &muram_offset, 4);

	if (n < 4)

		return -1;



	scdp->open = cpm_serial_open;

	scdp->putc = cpm_serial_putc;

arch/powerpc/boot/dts/ep88xc.dts

+12 −1
Original line number Diff line number Diff line
@@ -142,9 +142,20 @@ 
			command-proc = <9c0>;

			interrupts = <0>;	// cpm error interrupt

			interrupt-parent = <&CPM_PIC>;

			reg = <9c0 40 2000 1c00>;

			reg = <9c0 40>;

			ranges;



			muram@2000 {

				#address-cells = <1>;

				#size-cells = <1>;

				ranges = <0 2000 2000>;



				data@0 {

					compatible = "fsl,cpm-muram-data";

					reg = <0 1c00>;

				};

			};



			brg@9f0 {

				compatible = "fsl,mpc885-brg",

				             "fsl,cpm1-brg",

arch/powerpc/boot/dts/mpc8272ads.dts

+11 −0
Original line number Diff line number Diff line
@@ -124,6 +124,17 @@ 
			reg = <119c0 30 0 2000>;

			ranges;



			muram@0 {

				#address-cells = <1>;

				#size-cells = <1>;

				ranges = <0 0 10000>;



				data@0 {

					compatible = "fsl,cpm-muram-data";

					reg = <0 2000 9800 800>;

				};

			};



			brg@119f0 {

				compatible = "fsl,mpc8272-brg",

				             "fsl,cpm2-brg",

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