 9598c1bb39
			
		
	
	
		9598c1bb39
		
	
	
	
	
		
			
			The traditional ptimer behaviour includes a collection of weird edge case behaviours. In 2016 we improved the ptimer implementation to fix these and generally make the behaviour more flexible, with ptimers opting in to the new behaviour by passing an appropriate set of policy flags to ptimer_init(). For backwards-compatibility, we defined PTIMER_POLICY_DEFAULT (which sets no flags) to give the old weird behaviour. This turns out to be a poor choice of name, because people writing new devices which use ptimers are misled into thinking that the default is probably a sensible choice of flags, when in fact it is almost always not what you want. Rename PTIMER_POLICY_DEFAULT to PTIMER_POLICY_LEGACY and beef up the comment to more clearly say that new devices should not be using it. The code-change part of this commit was produced by sed -i -e 's/PTIMER_POLICY_DEFAULT/PTIMER_POLICY_LEGACY/g' $(git grep -l PTIMER_POLICY_DEFAULT) with the exception of a test name string change in tests/unit/ptimer-test.c which was added manually. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Francisco Iglesias <francisco.iglesias@amd.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20220516103058.162280-1-peter.maydell@linaro.org
		
			
				
	
	
		
			446 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			446 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Samsung exynos4210 Pulse Width Modulation Timer
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|  *
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|  * Copyright (c) 2000 - 2011 Samsung Electronics Co., Ltd.
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|  * All rights reserved.
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|  *
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|  * Evgeny Voevodin <e.voevodin@samsung.com>
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|  *
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|  * This program is free software; you can redistribute it and/or modify it
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|  * under the terms of the GNU General Public License as published by the
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|  * Free Software Foundation; either version 2 of the License, or (at your
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|  * option) any later version.
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|  *
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|  * This program is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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|  * See the GNU General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU General Public License along
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|  * with this program; if not, see <http://www.gnu.org/licenses/>.
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|  */
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| 
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| #include "qemu/osdep.h"
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| #include "qemu/log.h"
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| #include "hw/sysbus.h"
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| #include "migration/vmstate.h"
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| #include "qemu/timer.h"
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| #include "qemu/module.h"
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| #include "hw/ptimer.h"
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| 
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| #include "hw/arm/exynos4210.h"
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| #include "hw/irq.h"
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| #include "qom/object.h"
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| 
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| //#define DEBUG_PWM
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| 
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| #ifdef DEBUG_PWM
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| #define DPRINTF(fmt, ...) \
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|         do { fprintf(stdout, "PWM: [%24s:%5d] " fmt, __func__, __LINE__, \
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|                 ## __VA_ARGS__); } while (0)
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| #else
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| #define DPRINTF(fmt, ...) do {} while (0)
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| #endif
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| 
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| #define     EXYNOS4210_PWM_TIMERS_NUM      5
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| #define     EXYNOS4210_PWM_REG_MEM_SIZE    0x50
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| 
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| #define     TCFG0        0x0000
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| #define     TCFG1        0x0004
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| #define     TCON         0x0008
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| #define     TCNTB0       0x000C
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| #define     TCMPB0       0x0010
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| #define     TCNTO0       0x0014
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| #define     TCNTB1       0x0018
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| #define     TCMPB1       0x001C
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| #define     TCNTO1       0x0020
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| #define     TCNTB2       0x0024
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| #define     TCMPB2       0x0028
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| #define     TCNTO2       0x002C
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| #define     TCNTB3       0x0030
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| #define     TCMPB3       0x0034
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| #define     TCNTO3       0x0038
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| #define     TCNTB4       0x003C
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| #define     TCNTO4       0x0040
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| #define     TINT_CSTAT   0x0044
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| 
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| #define     TCNTB(x)    (0xC * (x))
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| #define     TCMPB(x)    (0xC * (x) + 1)
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| #define     TCNTO(x)    (0xC * (x) + 2)
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| 
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| #define GET_PRESCALER(reg, x) (((reg) & (0xFF << (8 * (x)))) >> 8 * (x))
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| #define GET_DIVIDER(reg, x) (1 << (((reg) & (0xF << (4 * (x)))) >> (4 * (x))))
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| 
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| /*
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|  * Attention! Timer4 doesn't have OUTPUT_INVERTER,
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|  * so Auto Reload bit is not accessible by macros!
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|  */
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| #define     TCON_TIMER_BASE(x)          (((x) ? 1 : 0) * 4 + 4 * (x))
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| #define     TCON_TIMER_START(x)         (1 << (TCON_TIMER_BASE(x) + 0))
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| #define     TCON_TIMER_MANUAL_UPD(x)    (1 << (TCON_TIMER_BASE(x) + 1))
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| #define     TCON_TIMER_OUTPUT_INV(x)    (1 << (TCON_TIMER_BASE(x) + 2))
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| #define     TCON_TIMER_AUTO_RELOAD(x)   (1 << (TCON_TIMER_BASE(x) + 3))
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| #define     TCON_TIMER4_AUTO_RELOAD     (1 << 22)
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| 
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| #define     TINT_CSTAT_STATUS(x)        (1 << (5 + (x)))
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| #define     TINT_CSTAT_ENABLE(x)        (1 << (x))
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| 
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| /* timer struct */
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| typedef struct {
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|     uint32_t    id;             /* timer id */
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|     qemu_irq    irq;            /* local timer irq */
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|     uint32_t    freq;           /* timer frequency */
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| 
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|     /* use ptimer.c to represent count down timer */
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|     ptimer_state *ptimer;       /* timer  */
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| 
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|     /* registers */
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|     uint32_t    reg_tcntb;      /* counter register buffer */
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|     uint32_t    reg_tcmpb;      /* compare register buffer */
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| 
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|     struct Exynos4210PWMState *parent;
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| 
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| } Exynos4210PWM;
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| 
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| #define TYPE_EXYNOS4210_PWM "exynos4210.pwm"
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| OBJECT_DECLARE_SIMPLE_TYPE(Exynos4210PWMState, EXYNOS4210_PWM)
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| 
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| struct Exynos4210PWMState {
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|     SysBusDevice parent_obj;
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| 
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|     MemoryRegion iomem;
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| 
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|     uint32_t    reg_tcfg[2];
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|     uint32_t    reg_tcon;
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|     uint32_t    reg_tint_cstat;
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| 
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|     Exynos4210PWM timer[EXYNOS4210_PWM_TIMERS_NUM];
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| 
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| };
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| 
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| /*** VMState ***/
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| static const VMStateDescription vmstate_exynos4210_pwm = {
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|     .name = "exynos4210.pwm.pwm",
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|     .version_id = 1,
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|     .minimum_version_id = 1,
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|     .fields = (VMStateField[]) {
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|         VMSTATE_UINT32(id, Exynos4210PWM),
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|         VMSTATE_UINT32(freq, Exynos4210PWM),
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|         VMSTATE_PTIMER(ptimer, Exynos4210PWM),
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|         VMSTATE_UINT32(reg_tcntb, Exynos4210PWM),
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|         VMSTATE_UINT32(reg_tcmpb, Exynos4210PWM),
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|         VMSTATE_END_OF_LIST()
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|     }
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| };
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| 
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| static const VMStateDescription vmstate_exynos4210_pwm_state = {
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|     .name = "exynos4210.pwm",
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|     .version_id = 1,
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|     .minimum_version_id = 1,
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|     .fields = (VMStateField[]) {
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|         VMSTATE_UINT32_ARRAY(reg_tcfg, Exynos4210PWMState, 2),
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|         VMSTATE_UINT32(reg_tcon, Exynos4210PWMState),
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|         VMSTATE_UINT32(reg_tint_cstat, Exynos4210PWMState),
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|         VMSTATE_STRUCT_ARRAY(timer, Exynos4210PWMState,
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|             EXYNOS4210_PWM_TIMERS_NUM, 0,
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|         vmstate_exynos4210_pwm, Exynos4210PWM),
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|         VMSTATE_END_OF_LIST()
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|     }
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| };
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| 
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| /*
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|  * PWM update frequency.
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|  * Must be called within a ptimer_transaction_begin/commit block
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|  * for s->timer[id].ptimer.
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|  */
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| static void exynos4210_pwm_update_freq(Exynos4210PWMState *s, uint32_t id)
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| {
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|     uint32_t freq;
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|     freq = s->timer[id].freq;
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|     if (id > 1) {
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|         s->timer[id].freq = 24000000 /
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|         ((GET_PRESCALER(s->reg_tcfg[0], 1) + 1) *
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|                 (GET_DIVIDER(s->reg_tcfg[1], id)));
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|     } else {
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|         s->timer[id].freq = 24000000 /
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|         ((GET_PRESCALER(s->reg_tcfg[0], 0) + 1) *
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|                 (GET_DIVIDER(s->reg_tcfg[1], id)));
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|     }
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| 
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|     if (freq != s->timer[id].freq) {
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|         ptimer_set_freq(s->timer[id].ptimer, s->timer[id].freq);
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|         DPRINTF("freq=%uHz\n", s->timer[id].freq);
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|     }
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| }
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| 
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| /*
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|  * Counter tick handler
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|  */
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| static void exynos4210_pwm_tick(void *opaque)
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| {
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|     Exynos4210PWM *s = (Exynos4210PWM *)opaque;
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|     Exynos4210PWMState *p = (Exynos4210PWMState *)s->parent;
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|     uint32_t id = s->id;
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|     bool cmp;
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| 
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|     DPRINTF("timer %u tick\n", id);
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| 
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|     /* set irq status */
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|     p->reg_tint_cstat |= TINT_CSTAT_STATUS(id);
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| 
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|     /* raise IRQ */
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|     if (p->reg_tint_cstat & TINT_CSTAT_ENABLE(id)) {
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|         DPRINTF("timer %u IRQ\n", id);
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|         qemu_irq_raise(p->timer[id].irq);
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|     }
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| 
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|     /* reload timer */
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|     if (id != 4) {
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|         cmp = p->reg_tcon & TCON_TIMER_AUTO_RELOAD(id);
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|     } else {
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|         cmp = p->reg_tcon & TCON_TIMER4_AUTO_RELOAD;
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|     }
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| 
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|     if (cmp) {
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|         DPRINTF("auto reload timer %u count to %x\n", id,
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|                 p->timer[id].reg_tcntb);
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|         ptimer_set_count(p->timer[id].ptimer, p->timer[id].reg_tcntb);
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|         ptimer_run(p->timer[id].ptimer, 1);
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|     } else {
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|         /* stop timer, set status to STOP, see Basic Timer Operation */
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|         p->reg_tcon &= ~TCON_TIMER_START(id);
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|         ptimer_stop(p->timer[id].ptimer);
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|     }
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| }
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| 
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| /*
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|  * PWM Read
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|  */
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| static uint64_t exynos4210_pwm_read(void *opaque, hwaddr offset,
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|         unsigned size)
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| {
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|     Exynos4210PWMState *s = (Exynos4210PWMState *)opaque;
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|     uint32_t value = 0;
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|     int index;
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| 
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|     switch (offset) {
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|     case TCFG0: case TCFG1:
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|         index = (offset - TCFG0) >> 2;
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|         value = s->reg_tcfg[index];
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|         break;
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| 
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|     case TCON:
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|         value = s->reg_tcon;
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|         break;
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| 
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|     case TCNTB0: case TCNTB1:
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|     case TCNTB2: case TCNTB3: case TCNTB4:
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|         index = (offset - TCNTB0) / 0xC;
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|         value = s->timer[index].reg_tcntb;
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|         break;
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| 
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|     case TCMPB0: case TCMPB1:
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|     case TCMPB2: case TCMPB3:
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|         index = (offset - TCMPB0) / 0xC;
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|         value = s->timer[index].reg_tcmpb;
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|         break;
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| 
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|     case TCNTO0: case TCNTO1:
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|     case TCNTO2: case TCNTO3: case TCNTO4:
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|         index = (offset == TCNTO4) ? 4 : (offset - TCNTO0) / 0xC;
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|         value = ptimer_get_count(s->timer[index].ptimer);
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|         break;
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| 
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|     case TINT_CSTAT:
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|         value = s->reg_tint_cstat;
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|         break;
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| 
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|     default:
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|         qemu_log_mask(LOG_GUEST_ERROR,
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|                       "exynos4210.pwm: bad read offset " TARGET_FMT_plx,
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|                       offset);
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|         break;
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|     }
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|     return value;
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| }
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| 
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| /*
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|  * PWM Write
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|  */
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| static void exynos4210_pwm_write(void *opaque, hwaddr offset,
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|         uint64_t value, unsigned size)
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| {
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|     Exynos4210PWMState *s = (Exynos4210PWMState *)opaque;
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|     int index;
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|     uint32_t new_val;
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|     int i;
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| 
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|     switch (offset) {
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|     case TCFG0: case TCFG1:
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|         index = (offset - TCFG0) >> 2;
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|         s->reg_tcfg[index] = value;
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| 
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|         /* update timers frequencies */
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|         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
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|             ptimer_transaction_begin(s->timer[i].ptimer);
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|             exynos4210_pwm_update_freq(s, s->timer[i].id);
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|             ptimer_transaction_commit(s->timer[i].ptimer);
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|         }
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|         break;
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| 
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|     case TCON:
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|         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
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|             ptimer_transaction_begin(s->timer[i].ptimer);
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|             if ((value & TCON_TIMER_MANUAL_UPD(i)) >
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|             (s->reg_tcon & TCON_TIMER_MANUAL_UPD(i))) {
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|                 /*
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|                  * TCNTB and TCMPB are loaded into TCNT and TCMP.
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|                  * Update timers.
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|                  */
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| 
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|                 /* this will start timer to run, this ok, because
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|                  * during processing start bit timer will be stopped
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|                  * if needed */
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|                 ptimer_set_count(s->timer[i].ptimer, s->timer[i].reg_tcntb);
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|                 DPRINTF("set timer %d count to %x\n", i,
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|                         s->timer[i].reg_tcntb);
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|             }
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| 
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|             if ((value & TCON_TIMER_START(i)) >
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|             (s->reg_tcon & TCON_TIMER_START(i))) {
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|                 /* changed to start */
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|                 ptimer_run(s->timer[i].ptimer, 1);
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|                 DPRINTF("run timer %d\n", i);
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|             }
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| 
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|             if ((value & TCON_TIMER_START(i)) <
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|                     (s->reg_tcon & TCON_TIMER_START(i))) {
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|                 /* changed to stop */
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|                 ptimer_stop(s->timer[i].ptimer);
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|                 DPRINTF("stop timer %d\n", i);
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|             }
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|             ptimer_transaction_commit(s->timer[i].ptimer);
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|         }
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|         s->reg_tcon = value;
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|         break;
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| 
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|     case TCNTB0: case TCNTB1:
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|     case TCNTB2: case TCNTB3: case TCNTB4:
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|         index = (offset - TCNTB0) / 0xC;
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|         s->timer[index].reg_tcntb = value;
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|         break;
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| 
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|     case TCMPB0: case TCMPB1:
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|     case TCMPB2: case TCMPB3:
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|         index = (offset - TCMPB0) / 0xC;
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|         s->timer[index].reg_tcmpb = value;
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|         break;
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| 
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|     case TINT_CSTAT:
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|         new_val = (s->reg_tint_cstat & 0x3E0) + (0x1F & value);
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|         new_val &= ~(0x3E0 & value);
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| 
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|         for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
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|             if ((new_val & TINT_CSTAT_STATUS(i)) <
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|                     (s->reg_tint_cstat & TINT_CSTAT_STATUS(i))) {
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|                 qemu_irq_lower(s->timer[i].irq);
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|             }
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|         }
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| 
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|         s->reg_tint_cstat = new_val;
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|         break;
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| 
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|     default:
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|         qemu_log_mask(LOG_GUEST_ERROR,
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|                       "exynos4210.pwm: bad write offset " TARGET_FMT_plx,
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|                       offset);
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|         break;
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| 
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|     }
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| }
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| 
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| /*
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|  * Set default values to timer fields and registers
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|  */
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| static void exynos4210_pwm_reset(DeviceState *d)
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| {
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|     Exynos4210PWMState *s = EXYNOS4210_PWM(d);
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|     int i;
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|     s->reg_tcfg[0] = 0x0101;
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|     s->reg_tcfg[1] = 0x0;
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|     s->reg_tcon = 0;
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|     s->reg_tint_cstat = 0;
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|     for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
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|         s->timer[i].reg_tcmpb = 0;
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|         s->timer[i].reg_tcntb = 0;
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| 
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|         ptimer_transaction_begin(s->timer[i].ptimer);
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|         exynos4210_pwm_update_freq(s, s->timer[i].id);
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|         ptimer_stop(s->timer[i].ptimer);
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|         ptimer_transaction_commit(s->timer[i].ptimer);
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|     }
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| }
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| 
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| static const MemoryRegionOps exynos4210_pwm_ops = {
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|     .read = exynos4210_pwm_read,
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|     .write = exynos4210_pwm_write,
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|     .endianness = DEVICE_NATIVE_ENDIAN,
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| };
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| 
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| /*
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|  * PWM timer initialization
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|  */
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| static void exynos4210_pwm_init(Object *obj)
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| {
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|     Exynos4210PWMState *s = EXYNOS4210_PWM(obj);
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|     SysBusDevice *dev = SYS_BUS_DEVICE(obj);
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|     int i;
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| 
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|     for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
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|         sysbus_init_irq(dev, &s->timer[i].irq);
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|         s->timer[i].ptimer = ptimer_init(exynos4210_pwm_tick,
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|                                          &s->timer[i],
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|                                          PTIMER_POLICY_LEGACY);
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|         s->timer[i].id = i;
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|         s->timer[i].parent = s;
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|     }
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| 
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|     memory_region_init_io(&s->iomem, obj, &exynos4210_pwm_ops, s,
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|                           "exynos4210-pwm", EXYNOS4210_PWM_REG_MEM_SIZE);
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|     sysbus_init_mmio(dev, &s->iomem);
 | |
| }
 | |
| 
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| static void exynos4210_pwm_finalize(Object *obj)
 | |
| {
 | |
|     Exynos4210PWMState *s = EXYNOS4210_PWM(obj);
 | |
|     int i;
 | |
| 
 | |
|     for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {
 | |
|         ptimer_free(s->timer[i].ptimer);
 | |
|     }
 | |
| }
 | |
| 
 | |
| static void exynos4210_pwm_class_init(ObjectClass *klass, void *data)
 | |
| {
 | |
|     DeviceClass *dc = DEVICE_CLASS(klass);
 | |
| 
 | |
|     dc->reset = exynos4210_pwm_reset;
 | |
|     dc->vmsd = &vmstate_exynos4210_pwm_state;
 | |
| }
 | |
| 
 | |
| static const TypeInfo exynos4210_pwm_info = {
 | |
|     .name          = TYPE_EXYNOS4210_PWM,
 | |
|     .parent        = TYPE_SYS_BUS_DEVICE,
 | |
|     .instance_size = sizeof(Exynos4210PWMState),
 | |
|     .instance_init = exynos4210_pwm_init,
 | |
|     .instance_finalize = exynos4210_pwm_finalize,
 | |
|     .class_init    = exynos4210_pwm_class_init,
 | |
| };
 | |
| 
 | |
| static void exynos4210_pwm_register_types(void)
 | |
| {
 | |
|     type_register_static(&exynos4210_pwm_info);
 | |
| }
 | |
| 
 | |
| type_init(exynos4210_pwm_register_types)
 |