SuperH Interfaces Guide

Paul Mundt


      
     

Copyright © 2008 Paul Mundt

Copyright © 2008 Renesas Technology Corp.

This documentation is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License version 2 as published by the Free Software Foundation.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

For more details see the file COPYING in the source distribution of Linux.

Table of Contents

1. Memory Management
SH-4
Store Queue API
SH-5
TLB Interfaces
2. Clock Framework Extensions
clk_set_rate_ex — set the clock rate for a clock source, with additional parameter
3. Machine Specific Interfaces
mach-dreamcast
mach-x3proto
4. Busses
SuperHyway
Maple

Chapter 1. Memory Management

Table of Contents

SH-4
Store Queue API
SH-5
TLB Interfaces

SH-4

Store Queue API

Name

sq_flush_range — Flush (prefetch) a specific SQ range

Synopsis

void sq_flush_range (start,  
 len); 
unsigned long  start;
unsigned int  len;

Arguments

start

the store queue address to start flushing from

len

the length to flush

Description

Flushes the store queue cache from start to start + len in a linear fashion.

Name

sq_remap — Map a physical address through the Store Queues

Synopsis

unsigned long sq_remap (phys,  
 size,  
 name,  
 flags); 
unsigned long  phys;
unsigned int  size;
const char *  name;
unsigned long  flags;

Arguments

phys

Physical address of mapping.

size

Length of mapping.

name

User invoking mapping.

flags

Protection flags.

Description

Remaps the physical address phys through the next available store queue address of size length. name is logged at boot time as well as through the sysfs interface.

Name

sq_unmap — Unmap a Store Queue allocation

Synopsis

void sq_unmap (vaddr); 
unsigned long  vaddr;

Arguments

vaddr

Pre-allocated Store Queue mapping.

Description

Unmaps the store queue allocation map that was previously created by sq_remap. Also frees up the pte that was previously inserted into the kernel page table and discards the UTLB translation.

SH-5

TLB Interfaces

Name

sh64_tlb_init — Perform initial setup for the DTLB and ITLB.

Synopsis

int sh64_tlb_init (void); 
 void;

Arguments

void

no arguments

Name

sh64_next_free_dtlb_entry — Find the next available DTLB entry

Synopsis

unsigned long long sh64_next_free_dtlb_entry (void); 
 void;

Arguments

void

no arguments

Name

sh64_get_wired_dtlb_entry — Allocate a wired (locked-in) entry in the DTLB

Synopsis

unsigned long long sh64_get_wired_dtlb_entry (void); 
 void;

Arguments

void

no arguments

Name

sh64_put_wired_dtlb_entry — Free a wired (locked-in) entry in the DTLB.

Synopsis

int sh64_put_wired_dtlb_entry (entry); 
unsigned long long  entry;

Arguments

entry

Address of TLB slot.

Description

Works like a stack, last one to allocate must be first one to free.

Name

sh64_setup_tlb_slot — Load up a translation in a wired slot.

Synopsis

void sh64_setup_tlb_slot (config_addr,  
 eaddr,  
 asid,  
 paddr); 
unsigned long long  config_addr;
unsigned long  eaddr;
unsigned long  asid;
unsigned long  paddr;

Arguments

config_addr

Address of TLB slot.

eaddr

Virtual address.

asid

Address Space Identifier.

paddr

Physical address.

Description

Load up a virtual<->physical translation for eaddr<->paddr in the pre-allocated TLB slot config_addr (see sh64_get_wired_dtlb_entry).

Name

sh64_teardown_tlb_slot — Teardown a translation.

Synopsis

void sh64_teardown_tlb_slot (config_addr); 
unsigned long long  config_addr;

Arguments

config_addr

Address of TLB slot.

Description

Teardown any existing mapping in the TLB slot config_addr.

Name

for_each_dtlb_entry — Iterate over free (non-wired) DTLB entries

Synopsis

for_each_dtlb_entry (tlb); 
 tlb;

Arguments

tlb

TLB entry

Name

for_each_itlb_entry — Iterate over free (non-wired) ITLB entries

Synopsis

for_each_itlb_entry (tlb); 
 tlb;

Arguments

tlb

TLB entry

Name

__flush_tlb_slot — Flushes TLB slot slot.

Synopsis

void __flush_tlb_slot (slot); 
unsigned long long  slot;

Arguments

slot

Address of TLB slot.

Chapter 2. Clock Framework Extensions

Table of Contents

clk_set_rate_ex — set the clock rate for a clock source, with additional parameter

Name

clk_set_rate_ex — set the clock rate for a clock source, with additional parameter

Synopsis

int clk_set_rate_ex (clk,  
 rate,  
 algo_id); 
struct clk *  clk;
unsigned long  rate;
int  algo_id;

Arguments

clk

clock source

rate

desired clock rate in Hz

algo_id

algorithm id to be passed down to ops->set_rate

Description

Returns success (0) or negative errno.

Chapter 3. Machine Specific Interfaces

Table of Contents

mach-dreamcast
mach-x3proto

mach-dreamcast

Name

aica_rtc_gettimeofday — Get the time from the AICA RTC

Synopsis

void aica_rtc_gettimeofday (ts); 
struct timespec *  ts;

Arguments

ts

pointer to resulting timespec

Description

Grabs the current RTC seconds counter and adjusts it to the Unix Epoch.

Name

aica_rtc_settimeofday — Set the AICA RTC to the current time

Synopsis

int aica_rtc_settimeofday (secs); 
const time_t  secs;

Arguments

secs

contains the time_t to set

Description

Adjusts the given tv to the AICA Epoch and sets the RTC seconds counter.

mach-x3proto

Name

ilsel_enable — Enable an ILSEL set.

Synopsis

int ilsel_enable (set); 
ilsel_source_t  set;

Arguments

set

ILSEL source (see ilsel_source_t enum in include/asm-sh/ilsel.h).

Description

Enables a given non-aliased ILSEL source (<= ILSEL_KEY) at the highest available interrupt level. Callers should take care to order callsites noting descending interrupt levels. Aliasing FPGA and external board IRQs need to use ilsel_enable_fixed.

The return value is an IRQ number that can later be taken down with ilsel_disable.

Name

ilsel_enable_fixed — Enable an ILSEL set at a fixed interrupt level

Synopsis

int ilsel_enable_fixed (set,  
 level); 
ilsel_source_t  set;
unsigned int  level;

Arguments

set

ILSEL source (see ilsel_source_t enum in include/asm-sh/ilsel.h).

level

Interrupt level (1 - 15)

Description

Enables a given ILSEL source at a fixed interrupt level. Necessary both for level reservation as well as for aliased sources that only exist on special ILSEL#s.

Returns an IRQ number (as ilsel_enable).

Name

ilsel_disable — Disable an ILSEL set

Synopsis

void ilsel_disable (irq); 
unsigned int  irq;

Arguments

irq

Bit position for ILSEL set value (retval from enable routines)

Description

Disable a previously enabled ILSEL set.

Chapter 4. Busses

Table of Contents

SuperHyway
Maple

SuperHyway

Name

superhyway_add_device — Add a SuperHyway module

Synopsis

int superhyway_add_device (base,  
 sdev,  
 bus); 
unsigned long  base;
struct superhyway_device *  sdev;
struct superhyway_bus *  bus;

Arguments

base

Physical address where module is mapped.

sdev

SuperHyway device to add, or NULL to allocate a new one.

bus

Bus where SuperHyway module resides.

Description

This is responsible for adding a new SuperHyway module. This sets up a new struct superhyway_device for the module being added if sdev == NULL.

Devices are initially added in the order that they are scanned (from the top-down of the memory map), and are assigned an ID based on the order that they are added. Any manual addition of a module will thus get the ID after the devices already discovered regardless of where it resides in memory.

Further work can and should be done in superhyway_scan_bus, to be sure that any new modules are properly discovered and subsequently registered.

Name

superhyway_register_driver — Register a new SuperHyway driver

Synopsis

int superhyway_register_driver (drv); 
struct superhyway_driver *  drv;

Arguments

drv

SuperHyway driver to register.

Description

This registers the passed in drv. Any devices matching the id table will automatically be populated and handed off to the driver's specified probe routine.

Name

superhyway_unregister_driver — Unregister a SuperHyway driver

Synopsis

void superhyway_unregister_driver (drv); 
struct superhyway_driver *  drv;

Arguments

drv

SuperHyway driver to unregister.

Description

This cleans up after superhyway_register_driver, and should be invoked in the exit path of any module drivers.

Maple

Name

maple_driver_register — register a maple driver

Synopsis

int maple_driver_register (drv); 
struct maple_driver *  drv;

Arguments

drv

maple driver to be registered.

Description

Registers the passed in drv, while updating the bus type. Devices with matching function IDs will be automatically probed.

Name

maple_driver_unregister — unregister a maple driver.

Synopsis

void maple_driver_unregister (drv); 
struct maple_driver *  drv;

Arguments

drv

maple driver to unregister.

Description

Cleans up after maple_driver_register. To be invoked in the exit path of any module drivers.

Name

maple_getcond_callback — setup handling MAPLE_COMMAND_GETCOND

Synopsis

void maple_getcond_callback (dev,  
 callback,  
 interval,  
 function); 
struct maple_device *  dev;
void (* callback(struct mapleq *mq);
unsigned long  interval;
unsigned long  function;

Arguments

dev

device responding

callback

handler callback

interval

interval in jiffies between callbacks

function

the function code for the device

Name

maple_add_packet — add a single instruction to the maple bus queue

Synopsis

int maple_add_packet (mdev,  
 function,  
 command,  
 length,  
 data); 
struct maple_device *  mdev;
u32  function;
u32  command;
size_t  length;
void *  data;

Arguments

mdev

maple device

function

function on device being queried

command

maple command to add

length

length of command string (in 32 bit words)

data

remainder of command string