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atmel_tc library

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Create <linux/atmel_tc.h> based on <asm-arm/arch-at91/at91-tc.h> and the
at91sam9263 and at32ap7000 datasheets.  Most AT91 and AT32 SOCs have one
or two of these TC blocks, which include three 16-bit timers that can be
interconnected in various ways.

These TC blocks can be used for external interfacing (such as PWM and
measurement), or used as somewhat quirky sixteen-bit timers.

Changes relative to the original version:
  * Drop unneeded inclusion of <linux/mutex.h>
  * Support an arbitrary number of TC blocks
  * Return a struct with information about a TC block from
    atmel_tc_alloc() instead of using a combination of return values
    and "out" parameters.
  * ioremap() the I/O registers on allocation
  * Look up clocks and irqs for all channels
  * Add "name" parameter to atmel_tc_alloc() and use this when
    requesting the iomem resource.
  * Check if the platform provided the necessary resources at probe()
    time instead of when the TCB is allocated.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
This commit is contained in:
David Brownell 2008-02-22 17:23:23 -08:00 committed by Haavard Skinnemoen
parent 976dde010e
commit 2a341f5cf5
4 changed files with 422 additions and 0 deletions
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8
drivers/misc/Kconfig
View file

@ -22,6 +22,14 @@ config ATMEL_PWM
purposes including software controlled power-efficent backlights
on LCD displays, motor control, and waveform generation.
config ATMEL_TCLIB
bool "Atmel AT32/AT91 Timer/Counter Library"
depends on (AVR32 || ARCH_AT91)
help
Select this if you want a library to allocate the Timer/Counter
blocks found on many Atmel processors. This facilitates using
these blocks by different drivers despite processor differences.
config IBM_ASM
tristate "Device driver for IBM RSA service processor"
depends on X86 && PCI && INPUT && EXPERIMENTAL

1
drivers/misc/Makefile
View file

@ -10,6 +10,7 @@ obj-$(CONFIG_ACER_WMI) += acer-wmi.o
obj-$(CONFIG_ASUS_LAPTOP) += asus-laptop.o
obj-$(CONFIG_ATMEL_PWM) += atmel_pwm.o
obj-$(CONFIG_ATMEL_SSC) += atmel-ssc.o
obj-$(CONFIG_ATMEL_TCLIB) += atmel_tclib.o
obj-$(CONFIG_TC1100_WMI) += tc1100-wmi.o
obj-$(CONFIG_LKDTM) += lkdtm.o
obj-$(CONFIG_TIFM_CORE) += tifm_core.o

161
drivers/misc/atmel_tclib.c Normal file
View file

@ -0,0 +1,161 @@
#include <linux/atmel_tc.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
/* Number of bytes to reserve for the iomem resource */
#define ATMEL_TC_IOMEM_SIZE 256
/*
* This is a thin library to solve the problem of how to portably allocate
* one of the TC blocks. For simplicity, it doesn't currently expect to
* share individual timers between different drivers.
*/
#if defined(CONFIG_AVR32)
/* AVR32 has these divide PBB */
const u8 atmel_tc_divisors[5] = { 0, 4, 8, 16, 32, };
EXPORT_SYMBOL(atmel_tc_divisors);
#elif defined(CONFIG_ARCH_AT91)
/* AT91 has these divide MCK */
const u8 atmel_tc_divisors[5] = { 2, 8, 32, 128, 0, };
EXPORT_SYMBOL(atmel_tc_divisors);
#endif
static DEFINE_SPINLOCK(tc_list_lock);
static LIST_HEAD(tc_list);
/**
* atmel_tc_alloc - allocate a specified TC block
* @block: which block to allocate
* @name: name to be associated with the iomem resource
*
* Caller allocates a block. If it is available, a pointer to a
* pre-initialized struct atmel_tc is returned. The caller can access
* the registers directly through the "regs" field.
*/
struct atmel_tc *atmel_tc_alloc(unsigned block, const char *name)
{
struct atmel_tc *tc;
struct platform_device *pdev = NULL;
struct resource *r;
spin_lock(&tc_list_lock);
list_for_each_entry(tc, &tc_list, node) {
if (tc->pdev->id == block) {
pdev = tc->pdev;
break;
}
}
if (!pdev || tc->iomem)
goto fail;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
r = request_mem_region(r->start, ATMEL_TC_IOMEM_SIZE, name);
if (!r)
goto fail;
tc->regs = ioremap(r->start, ATMEL_TC_IOMEM_SIZE);
if (!tc->regs)
goto fail_ioremap;
tc->iomem = r;
out:
spin_unlock(&tc_list_lock);
return tc;
fail_ioremap:
release_resource(r);
fail:
tc = NULL;
goto out;
}
EXPORT_SYMBOL_GPL(atmel_tc_alloc);
/**
* atmel_tc_free - release a specified TC block
* @tc: Timer/counter block that was returned by atmel_tc_alloc()
*
* This reverses the effect of atmel_tc_alloc(), unmapping the I/O
* registers, invalidating the resource returned by that routine and
* making the TC available to other drivers.
*/
void atmel_tc_free(struct atmel_tc *tc)
{
spin_lock(&tc_list_lock);
if (tc->regs) {
iounmap(tc->regs);
release_resource(tc->iomem);
tc->regs = NULL;
tc->iomem = NULL;
}
spin_unlock(&tc_list_lock);
}
EXPORT_SYMBOL_GPL(atmel_tc_free);
static int __init tc_probe(struct platform_device *pdev)
{
struct atmel_tc *tc;
struct clk *clk;
int irq;
if (!platform_get_resource(pdev, IORESOURCE_MEM, 0))
return -EINVAL;
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return -EINVAL;
tc = kzalloc(sizeof(struct atmel_tc), GFP_KERNEL);
if (!tc)
return -ENOMEM;
tc->pdev = pdev;
clk = clk_get(&pdev->dev, "t0_clk");
if (IS_ERR(clk)) {
kfree(tc);
return -EINVAL;
}
tc->clk[0] = clk;
tc->clk[1] = clk_get(&pdev->dev, "t1_clk");
if (IS_ERR(tc->clk[1]))
tc->clk[1] = clk;
tc->clk[2] = clk_get(&pdev->dev, "t2_clk");
if (IS_ERR(tc->clk[2]))
tc->clk[2] = clk;
tc->irq[0] = irq;
tc->irq[1] = platform_get_irq(pdev, 1);
if (tc->irq[1] < 0)
tc->irq[1] = irq;
tc->irq[2] = platform_get_irq(pdev, 2);
if (tc->irq[2] < 0)
tc->irq[2] = irq;
spin_lock(&tc_list_lock);
list_add_tail(&tc->node, &tc_list);
spin_unlock(&tc_list_lock);
return 0;
}
static struct platform_driver tc_driver = {
.driver.name = "atmel_tcb",
};
static int __init tc_init(void)
{
return platform_driver_probe(&tc_driver, tc_probe);
}
arch_initcall(tc_init);

252
include/linux/atmel_tc.h Normal file
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@ -0,0 +1,252 @@
/*
* Timer/Counter Unit (TC) registers.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#ifndef ATMEL_TC_H
#define ATMEL_TC_H
#include <linux/compiler.h>
#include <linux/list.h>
/*
* Many 32-bit Atmel SOCs include one or more TC blocks, each of which holds
* three general-purpose 16-bit timers. These timers share one register bank.
* Depending on the SOC, each timer may have its own clock and IRQ, or those
* may be shared by the whole TC block.
*
* These TC blocks may have up to nine external pins: TCLK0..2 signals for
* clocks or clock gates, and per-timer TIOA and TIOB signals used for PWM
* or triggering. Those pins need to be set up for use with the TC block,
* else they will be used as GPIOs or for a different controller.
*
* Although we expect each TC block to have a platform_device node, those
* nodes are not what drivers bind to. Instead, they ask for a specific
* TC block, by number ... which is a common approach on systems with many
* timers. Then they use clk_get() and platform_get_irq() to get clock and
* IRQ resources.
*/
struct clk;
/**
* struct atmel_tc - information about a Timer/Counter Block
* @pdev: physical device
* @iomem: resource associated with the I/O register
* @regs: mapping through which the I/O registers can be accessed
* @irq: irq for each of the three channels
* @clk: internal clock source for each of the three channels
* @node: list node, for tclib internal use
*
* On some platforms, each TC channel has its own clocks and IRQs,
* while on others, all TC channels share the same clock and IRQ.
* Drivers should clk_enable() all the clocks they need even though
* all the entries in @clk may point to the same physical clock.
* Likewise, drivers should request irqs independently for each
* channel, but they must use IRQF_SHARED in case some of the entries
* in @irq are actually the same IRQ.
*/
struct atmel_tc {
struct platform_device *pdev;
struct resource *iomem;
void __iomem *regs;
int irq[3];
struct clk *clk[3];
struct list_head node;
};
extern struct atmel_tc *atmel_tc_alloc(unsigned block, const char *name);
extern void atmel_tc_free(struct atmel_tc *tc);
/* platform-specific ATMEL_TC_TIMER_CLOCKx divisors (0 means 32KiHz) */
extern const u8 atmel_tc_divisors[5];
/*
* Two registers have block-wide controls. These are: configuring the three
* "external" clocks (or event sources) used by the timer channels; and
* synchronizing the timers by resetting them all at once.
*
* "External" can mean "external to chip" using the TCLK0, TCLK1, or TCLK2
* signals. Or, it can mean "external to timer", using the TIOA output from
* one of the other two timers that's being run in waveform mode.
*/
#define ATMEL_TC_BCR 0xc0 /* TC Block Control Register */
#define ATMEL_TC_SYNC (1 << 0) /* synchronize timers */
#define ATMEL_TC_BMR 0xc4 /* TC Block Mode Register */
#define ATMEL_TC_TC0XC0S (3 << 0) /* external clock 0 source */
#define ATMEL_TC_TC0XC0S_TCLK0 (0 << 0)
#define ATMEL_TC_TC0XC0S_NONE (1 << 0)
#define ATMEL_TC_TC0XC0S_TIOA1 (2 << 0)
#define ATMEL_TC_TC0XC0S_TIOA2 (3 << 0)
#define ATMEL_TC_TC1XC1S (3 << 2) /* external clock 1 source */
#define ATMEL_TC_TC1XC1S_TCLK1 (0 << 2)
#define ATMEL_TC_TC1XC1S_NONE (1 << 2)
#define ATMEL_TC_TC1XC1S_TIOA0 (2 << 2)
#define ATMEL_TC_TC1XC1S_TIOA2 (3 << 2)
#define ATMEL_TC_TC2XC2S (3 << 4) /* external clock 2 source */
#define ATMEL_TC_TC2XC2S_TCLK2 (0 << 4)
#define ATMEL_TC_TC2XC2S_NONE (1 << 4)
#define ATMEL_TC_TC2XC2S_TIOA0 (2 << 4)
#define ATMEL_TC_TC2XC2S_TIOA1 (3 << 4)
/*
* Each TC block has three "channels", each with one counter and controls.
*
* Note that the semantics of ATMEL_TC_TIMER_CLOCKx (input clock selection
* when it's not "external") is silicon-specific. AT91 platforms use one
* set of definitions; AVR32 platforms use a different set. Don't hard-wire
* such knowledge into your code, use the global "atmel_tc_divisors" ...
* where index N is the divisor for clock N+1, else zero to indicate it uses
* the 32 KiHz clock.
*
* The timers can be chained in various ways, and operated in "waveform"
* generation mode (including PWM) or "capture" mode (to time events). In
* both modes, behavior can be configured in many ways.
*
* Each timer has two I/O pins, TIOA and TIOB. Waveform mode uses TIOA as a
* PWM output, and TIOB as either another PWM or as a trigger. Capture mode
* uses them only as inputs.
*/
#define ATMEL_TC_CHAN(idx) ((idx)*0x40)
#define ATMEL_TC_REG(idx, reg) (ATMEL_TC_CHAN(idx) + ATMEL_TC_ ## reg)
#define ATMEL_TC_CCR 0x00 /* Channel Control Register */
#define ATMEL_TC_CLKEN (1 << 0) /* clock enable */
#define ATMEL_TC_CLKDIS (1 << 1) /* clock disable */
#define ATMEL_TC_SWTRG (1 << 2) /* software trigger */
#define ATMEL_TC_CMR 0x04 /* Channel Mode Register */
/* Both modes share some CMR bits */
#define ATMEL_TC_TCCLKS (7 << 0) /* clock source */
#define ATMEL_TC_TIMER_CLOCK1 (0 << 0)
#define ATMEL_TC_TIMER_CLOCK2 (1 << 0)
#define ATMEL_TC_TIMER_CLOCK3 (2 << 0)
#define ATMEL_TC_TIMER_CLOCK4 (3 << 0)
#define ATMEL_TC_TIMER_CLOCK5 (4 << 0)
#define ATMEL_TC_XC0 (5 << 0)
#define ATMEL_TC_XC1 (6 << 0)
#define ATMEL_TC_XC2 (7 << 0)
#define ATMEL_TC_CLKI (1 << 3) /* clock invert */
#define ATMEL_TC_BURST (3 << 4) /* clock gating */
#define ATMEL_TC_GATE_NONE (0 << 4)
#define ATMEL_TC_GATE_XC0 (1 << 4)
#define ATMEL_TC_GATE_XC1 (2 << 4)
#define ATMEL_TC_GATE_XC2 (3 << 4)
#define ATMEL_TC_WAVE (1 << 15) /* true = Waveform mode */
/* CAPTURE mode CMR bits */
#define ATMEL_TC_LDBSTOP (1 << 6) /* counter stops on RB load */
#define ATMEL_TC_LDBDIS (1 << 7) /* counter disable on RB load */
#define ATMEL_TC_ETRGEDG (3 << 8) /* external trigger edge */
#define ATMEL_TC_ETRGEDG_NONE (0 << 8)
#define ATMEL_TC_ETRGEDG_RISING (1 << 8)
#define ATMEL_TC_ETRGEDG_FALLING (2 << 8)
#define ATMEL_TC_ETRGEDG_BOTH (3 << 8)
#define ATMEL_TC_ABETRG (1 << 10) /* external trigger is TIOA? */
#define ATMEL_TC_CPCTRG (1 << 14) /* RC compare trigger enable */
#define ATMEL_TC_LDRA (3 << 16) /* RA loading edge (of TIOA) */
#define ATMEL_TC_LDRA_NONE (0 << 16)
#define ATMEL_TC_LDRA_RISING (1 << 16)
#define ATMEL_TC_LDRA_FALLING (2 << 16)
#define ATMEL_TC_LDRA_BOTH (3 << 16)
#define ATMEL_TC_LDRB (3 << 18) /* RB loading edge (of TIOA) */
#define ATMEL_TC_LDRB_NONE (0 << 18)
#define ATMEL_TC_LDRB_RISING (1 << 18)
#define ATMEL_TC_LDRB_FALLING (2 << 18)
#define ATMEL_TC_LDRB_BOTH (3 << 18)
/* WAVEFORM mode CMR bits */
#define ATMEL_TC_CPCSTOP (1 << 6) /* RC compare stops counter */
#define ATMEL_TC_CPCDIS (1 << 7) /* RC compare disables counter */
#define ATMEL_TC_EEVTEDG (3 << 8) /* external event edge */
#define ATMEL_TC_EEVTEDG_NONE (0 << 8)
#define ATMEL_TC_EEVTEDG_RISING (1 << 8)
#define ATMEL_TC_EEVTEDG_FALLING (2 << 8)
#define ATMEL_TC_EEVTEDG_BOTH (3 << 8)
#define ATMEL_TC_EEVT (3 << 10) /* external event source */
#define ATMEL_TC_EEVT_TIOB (0 << 10)
#define ATMEL_TC_EEVT_XC0 (1 << 10)
#define ATMEL_TC_EEVT_XC1 (2 << 10)
#define ATMEL_TC_EEVT_XC2 (3 << 10)
#define ATMEL_TC_ENETRG (1 << 12) /* external event is trigger */
#define ATMEL_TC_WAVESEL (3 << 13) /* waveform type */
#define ATMEL_TC_WAVESEL_UP (0 << 13)
#define ATMEL_TC_WAVESEL_UPDOWN (1 << 13)
#define ATMEL_TC_WAVESEL_UP_AUTO (2 << 13)
#define ATMEL_TC_WAVESEL_UPDOWN_AUTO (3 << 13)
#define ATMEL_TC_ACPA (3 << 16) /* RA compare changes TIOA */
#define ATMEL_TC_ACPA_NONE (0 << 16)
#define ATMEL_TC_ACPA_SET (1 << 16)
#define ATMEL_TC_ACPA_CLEAR (2 << 16)
#define ATMEL_TC_ACPA_TOGGLE (3 << 16)
#define ATMEL_TC_ACPC (3 << 18) /* RC compare changes TIOA */
#define ATMEL_TC_ACPC_NONE (0 << 18)
#define ATMEL_TC_ACPC_SET (1 << 18)
#define ATMEL_TC_ACPC_CLEAR (2 << 18)
#define ATMEL_TC_ACPC_TOGGLE (3 << 18)
#define ATMEL_TC_AEEVT (3 << 20) /* external event changes TIOA */
#define ATMEL_TC_AEEVT_NONE (0 << 20)
#define ATMEL_TC_AEEVT_SET (1 << 20)
#define ATMEL_TC_AEEVT_CLEAR (2 << 20)
#define ATMEL_TC_AEEVT_TOGGLE (3 << 20)
#define ATMEL_TC_ASWTRG (3 << 22) /* software trigger changes TIOA */
#define ATMEL_TC_ASWTRG_NONE (0 << 22)
#define ATMEL_TC_ASWTRG_SET (1 << 22)
#define ATMEL_TC_ASWTRG_CLEAR (2 << 22)
#define ATMEL_TC_ASWTRG_TOGGLE (3 << 22)
#define ATMEL_TC_BCPB (3 << 24) /* RB compare changes TIOB */
#define ATMEL_TC_BCPB_NONE (0 << 24)
#define ATMEL_TC_BCPB_SET (1 << 24)
#define ATMEL_TC_BCPB_CLEAR (2 << 24)
#define ATMEL_TC_BCPB_TOGGLE (3 << 24)
#define ATMEL_TC_BCPC (3 << 26) /* RC compare changes TIOB */
#define ATMEL_TC_BCPC_NONE (0 << 26)
#define ATMEL_TC_BCPC_SET (1 << 26)
#define ATMEL_TC_BCPC_CLEAR (2 << 26)
#define ATMEL_TC_BCPC_TOGGLE (3 << 26)
#define ATMEL_TC_BEEVT (3 << 28) /* external event changes TIOB */
#define ATMEL_TC_BEEVT_NONE (0 << 28)
#define ATMEL_TC_BEEVT_SET (1 << 28)
#define ATMEL_TC_BEEVT_CLEAR (2 << 28)
#define ATMEL_TC_BEEVT_TOGGLE (3 << 28)
#define ATMEL_TC_BSWTRG (3 << 30) /* software trigger changes TIOB */
#define ATMEL_TC_BSWTRG_NONE (0 << 30)
#define ATMEL_TC_BSWTRG_SET (1 << 30)
#define ATMEL_TC_BSWTRG_CLEAR (2 << 30)
#define ATMEL_TC_BSWTRG_TOGGLE (3 << 30)
#define ATMEL_TC_CV 0x10 /* counter Value */
#define ATMEL_TC_RA 0x14 /* register A */
#define ATMEL_TC_RB 0x18 /* register B */
#define ATMEL_TC_RC 0x1c /* register C */
#define ATMEL_TC_SR 0x20 /* status (read-only) */
/* Status-only flags */
#define ATMEL_TC_CLKSTA (1 << 16) /* clock enabled */
#define ATMEL_TC_MTIOA (1 << 17) /* TIOA mirror */
#define ATMEL_TC_MTIOB (1 << 18) /* TIOB mirror */
#define ATMEL_TC_IER 0x24 /* interrupt enable (write-only) */
#define ATMEL_TC_IDR 0x28 /* interrupt disable (write-only) */
#define ATMEL_TC_IMR 0x2c /* interrupt mask (read-only) */
/* Status and IRQ flags */
#define ATMEL_TC_COVFS (1 << 0) /* counter overflow */
#define ATMEL_TC_LOVRS (1 << 1) /* load overrun */
#define ATMEL_TC_CPAS (1 << 2) /* RA compare */
#define ATMEL_TC_CPBS (1 << 3) /* RB compare */
#define ATMEL_TC_CPCS (1 << 4) /* RC compare */
#define ATMEL_TC_LDRAS (1 << 5) /* RA loading */
#define ATMEL_TC_LDRBS (1 << 6) /* RB loading */
#define ATMEL_TC_ETRGS (1 << 7) /* external trigger */
#endif