| /* |
| * SuperH Timer Support - MTU2 |
| * |
| * Copyright (C) 2009 Magnus Damm |
| * |
| * 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 |
| * |
| * 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 |
| */ |
| |
| #include <linux/init.h> |
| #include <linux/platform_device.h> |
| #include <linux/spinlock.h> |
| #include <linux/interrupt.h> |
| #include <linux/ioport.h> |
| #include <linux/delay.h> |
| #include <linux/io.h> |
| #include <linux/clk.h> |
| #include <linux/irq.h> |
| #include <linux/err.h> |
| #include <linux/clockchips.h> |
| #include <linux/sh_timer.h> |
| |
| struct sh_mtu2_priv { |
| void __iomem *mapbase; |
| struct clk *clk; |
| struct irqaction irqaction; |
| struct platform_device *pdev; |
| unsigned long rate; |
| unsigned long periodic; |
| struct clock_event_device ced; |
| }; |
| |
| static DEFINE_SPINLOCK(sh_mtu2_lock); |
| |
| #define TSTR -1 /* shared register */ |
| #define TCR 0 /* channel register */ |
| #define TMDR 1 /* channel register */ |
| #define TIOR 2 /* channel register */ |
| #define TIER 3 /* channel register */ |
| #define TSR 4 /* channel register */ |
| #define TCNT 5 /* channel register */ |
| #define TGR 6 /* channel register */ |
| |
| static unsigned long mtu2_reg_offs[] = { |
| [TCR] = 0, |
| [TMDR] = 1, |
| [TIOR] = 2, |
| [TIER] = 4, |
| [TSR] = 5, |
| [TCNT] = 6, |
| [TGR] = 8, |
| }; |
| |
| static inline unsigned long sh_mtu2_read(struct sh_mtu2_priv *p, int reg_nr) |
| { |
| struct sh_timer_config *cfg = p->pdev->dev.platform_data; |
| void __iomem *base = p->mapbase; |
| unsigned long offs; |
| |
| if (reg_nr == TSTR) |
| return ioread8(base + cfg->channel_offset); |
| |
| offs = mtu2_reg_offs[reg_nr]; |
| |
| if ((reg_nr == TCNT) || (reg_nr == TGR)) |
| return ioread16(base + offs); |
| else |
| return ioread8(base + offs); |
| } |
| |
| static inline void sh_mtu2_write(struct sh_mtu2_priv *p, int reg_nr, |
| unsigned long value) |
| { |
| struct sh_timer_config *cfg = p->pdev->dev.platform_data; |
| void __iomem *base = p->mapbase; |
| unsigned long offs; |
| |
| if (reg_nr == TSTR) { |
| iowrite8(value, base + cfg->channel_offset); |
| return; |
| } |
| |
| offs = mtu2_reg_offs[reg_nr]; |
| |
| if ((reg_nr == TCNT) || (reg_nr == TGR)) |
| iowrite16(value, base + offs); |
| else |
| iowrite8(value, base + offs); |
| } |
| |
| static void sh_mtu2_start_stop_ch(struct sh_mtu2_priv *p, int start) |
| { |
| struct sh_timer_config *cfg = p->pdev->dev.platform_data; |
| unsigned long flags, value; |
| |
| /* start stop register shared by multiple timer channels */ |
| spin_lock_irqsave(&sh_mtu2_lock, flags); |
| value = sh_mtu2_read(p, TSTR); |
| |
| if (start) |
| value |= 1 << cfg->timer_bit; |
| else |
| value &= ~(1 << cfg->timer_bit); |
| |
| sh_mtu2_write(p, TSTR, value); |
| spin_unlock_irqrestore(&sh_mtu2_lock, flags); |
| } |
| |
| static int sh_mtu2_enable(struct sh_mtu2_priv *p) |
| { |
| struct sh_timer_config *cfg = p->pdev->dev.platform_data; |
| int ret; |
| |
| /* enable clock */ |
| ret = clk_enable(p->clk); |
| if (ret) { |
| pr_err("sh_mtu2: cannot enable clock \"%s\"\n", cfg->clk); |
| return ret; |
| } |
| |
| /* make sure channel is disabled */ |
| sh_mtu2_start_stop_ch(p, 0); |
| |
| p->rate = clk_get_rate(p->clk) / 64; |
| p->periodic = (p->rate + HZ/2) / HZ; |
| |
| /* "Periodic Counter Operation" */ |
| sh_mtu2_write(p, TCR, 0x23); /* TGRA clear, divide clock by 64 */ |
| sh_mtu2_write(p, TIOR, 0); |
| sh_mtu2_write(p, TGR, p->periodic); |
| sh_mtu2_write(p, TCNT, 0); |
| sh_mtu2_write(p, TMDR, 0); |
| sh_mtu2_write(p, TIER, 0x01); |
| |
| /* enable channel */ |
| sh_mtu2_start_stop_ch(p, 1); |
| |
| return 0; |
| } |
| |
| static void sh_mtu2_disable(struct sh_mtu2_priv *p) |
| { |
| /* disable channel */ |
| sh_mtu2_start_stop_ch(p, 0); |
| |
| /* stop clock */ |
| clk_disable(p->clk); |
| } |
| |
| static irqreturn_t sh_mtu2_interrupt(int irq, void *dev_id) |
| { |
| struct sh_mtu2_priv *p = dev_id; |
| |
| /* acknowledge interrupt */ |
| sh_mtu2_read(p, TSR); |
| sh_mtu2_write(p, TSR, 0xfe); |
| |
| /* notify clockevent layer */ |
| p->ced.event_handler(&p->ced); |
| return IRQ_HANDLED; |
| } |
| |
| static struct sh_mtu2_priv *ced_to_sh_mtu2(struct clock_event_device *ced) |
| { |
| return container_of(ced, struct sh_mtu2_priv, ced); |
| } |
| |
| static void sh_mtu2_clock_event_mode(enum clock_event_mode mode, |
| struct clock_event_device *ced) |
| { |
| struct sh_mtu2_priv *p = ced_to_sh_mtu2(ced); |
| int disabled = 0; |
| |
| /* deal with old setting first */ |
| switch (ced->mode) { |
| case CLOCK_EVT_MODE_PERIODIC: |
| sh_mtu2_disable(p); |
| disabled = 1; |
| break; |
| default: |
| break; |
| } |
| |
| switch (mode) { |
| case CLOCK_EVT_MODE_PERIODIC: |
| pr_info("sh_mtu2: %s used for periodic clock events\n", |
| ced->name); |
| sh_mtu2_enable(p); |
| break; |
| case CLOCK_EVT_MODE_UNUSED: |
| if (!disabled) |
| sh_mtu2_disable(p); |
| break; |
| case CLOCK_EVT_MODE_SHUTDOWN: |
| default: |
| break; |
| } |
| } |
| |
| static void sh_mtu2_register_clockevent(struct sh_mtu2_priv *p, |
| char *name, unsigned long rating) |
| { |
| struct clock_event_device *ced = &p->ced; |
| int ret; |
| |
| memset(ced, 0, sizeof(*ced)); |
| |
| ced->name = name; |
| ced->features = CLOCK_EVT_FEAT_PERIODIC; |
| ced->rating = rating; |
| ced->cpumask = cpumask_of(0); |
| ced->set_mode = sh_mtu2_clock_event_mode; |
| |
| ret = setup_irq(p->irqaction.irq, &p->irqaction); |
| if (ret) { |
| pr_err("sh_mtu2: failed to request irq %d\n", |
| p->irqaction.irq); |
| return; |
| } |
| |
| pr_info("sh_mtu2: %s used for clock events\n", ced->name); |
| clockevents_register_device(ced); |
| } |
| |
| static int sh_mtu2_register(struct sh_mtu2_priv *p, char *name, |
| unsigned long clockevent_rating) |
| { |
| if (clockevent_rating) |
| sh_mtu2_register_clockevent(p, name, clockevent_rating); |
| |
| return 0; |
| } |
| |
| static int sh_mtu2_setup(struct sh_mtu2_priv *p, struct platform_device *pdev) |
| { |
| struct sh_timer_config *cfg = pdev->dev.platform_data; |
| struct resource *res; |
| int irq, ret; |
| ret = -ENXIO; |
| |
| memset(p, 0, sizeof(*p)); |
| p->pdev = pdev; |
| |
| if (!cfg) { |
| dev_err(&p->pdev->dev, "missing platform data\n"); |
| goto err0; |
| } |
| |
| platform_set_drvdata(pdev, p); |
| |
| res = platform_get_resource(p->pdev, IORESOURCE_MEM, 0); |
| if (!res) { |
| dev_err(&p->pdev->dev, "failed to get I/O memory\n"); |
| goto err0; |
| } |
| |
| irq = platform_get_irq(p->pdev, 0); |
| if (irq < 0) { |
| dev_err(&p->pdev->dev, "failed to get irq\n"); |
| goto err0; |
| } |
| |
| /* map memory, let mapbase point to our channel */ |
| p->mapbase = ioremap_nocache(res->start, resource_size(res)); |
| if (p->mapbase == NULL) { |
| pr_err("sh_mtu2: failed to remap I/O memory\n"); |
| goto err0; |
| } |
| |
| /* setup data for setup_irq() (too early for request_irq()) */ |
| p->irqaction.name = cfg->name; |
| p->irqaction.handler = sh_mtu2_interrupt; |
| p->irqaction.dev_id = p; |
| p->irqaction.irq = irq; |
| p->irqaction.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL; |
| p->irqaction.mask = CPU_MASK_NONE; |
| |
| /* get hold of clock */ |
| p->clk = clk_get(&p->pdev->dev, cfg->clk); |
| if (IS_ERR(p->clk)) { |
| pr_err("sh_mtu2: cannot get clock \"%s\"\n", cfg->clk); |
| ret = PTR_ERR(p->clk); |
| goto err1; |
| } |
| |
| return sh_mtu2_register(p, cfg->name, cfg->clockevent_rating); |
| err1: |
| iounmap(p->mapbase); |
| err0: |
| return ret; |
| } |
| |
| static int __devinit sh_mtu2_probe(struct platform_device *pdev) |
| { |
| struct sh_mtu2_priv *p = platform_get_drvdata(pdev); |
| struct sh_timer_config *cfg = pdev->dev.platform_data; |
| int ret; |
| |
| if (p) { |
| pr_info("sh_mtu2: %s kept as earlytimer\n", cfg->name); |
| return 0; |
| } |
| |
| p = kmalloc(sizeof(*p), GFP_KERNEL); |
| if (p == NULL) { |
| dev_err(&pdev->dev, "failed to allocate driver data\n"); |
| return -ENOMEM; |
| } |
| |
| ret = sh_mtu2_setup(p, pdev); |
| if (ret) { |
| kfree(p); |
| platform_set_drvdata(pdev, NULL); |
| } |
| return ret; |
| } |
| |
| static int __devexit sh_mtu2_remove(struct platform_device *pdev) |
| { |
| return -EBUSY; /* cannot unregister clockevent */ |
| } |
| |
| static struct platform_driver sh_mtu2_device_driver = { |
| .probe = sh_mtu2_probe, |
| .remove = __devexit_p(sh_mtu2_remove), |
| .driver = { |
| .name = "sh_mtu2", |
| } |
| }; |
| |
| static int __init sh_mtu2_init(void) |
| { |
| return platform_driver_register(&sh_mtu2_device_driver); |
| } |
| |
| static void __exit sh_mtu2_exit(void) |
| { |
| platform_driver_unregister(&sh_mtu2_device_driver); |
| } |
| |
| early_platform_init("earlytimer", &sh_mtu2_device_driver); |
| module_init(sh_mtu2_init); |
| module_exit(sh_mtu2_exit); |
| |
| MODULE_AUTHOR("Magnus Damm"); |
| MODULE_DESCRIPTION("SuperH MTU2 Timer Driver"); |
| MODULE_LICENSE("GPL v2"); |