[patch 2.6.25-rc2-git 1/2] atmel_tc library
From: David Brownell
Date: Fri Feb 22 2008 - 20:33:52 EST
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.
Signed-off-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
---
Note that this won't be usable until the AT91 and AT32 platforms
incorporate patches to configure the relevant platform devices.
Those changes are probably 2.6.26 material.
drivers/misc/Kconfig | 8 +
drivers/misc/Makefile | 1
drivers/misc/atmel_tclib.c | 107 +++++++++++++++++++++
include/linux/atmel_tc.h | 221 +++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 337 insertions(+)
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -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
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -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
--- /dev/null
+++ b/drivers/misc/atmel_tclib.c
@@ -0,0 +1,107 @@
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/ioport.h>
+#include <linux/platform_device.h>
+#include <linux/atmel_tc.h>
+
+
+/*
+ * 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
+
+/* we "know" that there will be either one or two TC blocks */
+static struct platform_device *blocks[2];
+
+
+/**
+ * atmel_tc_alloc - allocate a specified TC block
+ * @block: which block to allocate
+ * @iomem: used to return its IO memory resource
+ *
+ * Caller allocates a block. If it is available, its I/O space is requested
+ * and returned through the iomem pointer, and the device node for the block
+ * is returned. When it is not available, NULL is returned.
+ *
+ * On some platforms, each TC channel has its own clocks and IRQs. Drivers
+ * should clk_get() and clk_enable() "t0_clk", "t1_clk, and "t2_clk".
+ * In the same vein, they should platform_get_irq() for irqs 0, 1, and 2.
+ * On other platforms, only irq 0 and "t0_clk" will be available; drivers
+ * should handle with both configurations.
+ */
+struct platform_device *atmel_tc_alloc(unsigned block, struct resource **iomem)
+{
+ struct platform_device *tc;
+ struct resource *r;
+
+ if (block >= ARRAY_SIZE(blocks) || !iomem)
+ return NULL;
+
+ tc = blocks[block];
+ if (tc) {
+ r = platform_get_resource(tc, IORESOURCE_MEM, 0);
+ if (r)
+ r = request_mem_region(r->start, 256, NULL);
+ *iomem = r;
+ if (!r)
+ tc = NULL;
+ }
+
+ return tc;
+}
+EXPORT_SYMBOL_GPL(atmel_tc_alloc);
+
+/**
+ * atmel_tc_free - release a specified TC block
+ * @block: which block to release
+ *
+ * This reverses the effect of atmel_tc_alloc(), invalidating the resource
+ * returned by that routine and making the TC available to other drivers.
+ */
+void atmel_tc_free(struct platform_device *tc)
+{
+ if (tc->id >= 0 && tc->id < ARRAY_SIZE(blocks)) {
+ struct resource *r;
+
+ r = platform_get_resource(tc, IORESOURCE_MEM, 0);
+ release_mem_region(r->start, 256);
+ }
+}
+EXPORT_SYMBOL_GPL(atmel_tc_free);
+
+static int __init tc_probe(struct platform_device *pdev)
+{
+ static char __initdata e2big[] =
+ KERN_ERR "tclib: can't record TC block %d\n";
+
+ if (pdev->id < 0 || pdev->id >= ARRAY_SIZE(blocks)) {
+ printk(e2big, pdev->id);
+ return -ENFILE;
+ }
+ blocks[pdev->id] = pdev;
+ 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);
--- /dev/null
+++ b/include/linux/atmel_tc.h
@@ -0,0 +1,221 @@
+/*
+ * 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
+
+/*
+ * 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.
+ */
+extern struct platform_device *atmel_tc_alloc(unsigned block,
+ struct resource **iomem);
+extern void atmel_tc_free(struct platform_device *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
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