text: /*
   * Based on sound/arm/pxa2xx-ac97.c and sound/soc/pxa/pxa2xx-ac97.c
   * which contain:
   *
   * Author:	Nicolas Pitre
   * Created:	Dec 02, 2004
   * Copyright:	MontaVista Software Inc.
   *
   * This program 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.
   */
  
  #include <linux/kernel.h>
  #include <linux/platform_device.h>
  #include <linux/interrupt.h>
  #include <linux/clk.h>
  #include <linux/delay.h>
  #include <linux/module.h>
  
  #include <sound/ac97_codec.h>
  #include <sound/pxa2xx-lib.h>
  
  #include <asm/irq.h>
  #include <mach/regs-ac97.h>
  #include <mach/audio.h>
  
  static DEFINE_MUTEX(car_mutex);
  static DECLARE_WAIT_QUEUE_HEAD(gsr_wq);
  static volatile long gsr_bits;
  static struct clk *ac97_clk;
  static struct clk *ac97conf_clk;
  static int reset_gpio;
  
  extern void pxa27x_assert_ac97reset(int reset_gpio, int on);
  
  /*
   * Beware PXA27x bugs:
   *
   *   o Slot 12 read from modem space will hang controller.
   *   o CDONE, SDONE interrupt fails after any slot 12 IO.
   *
   * We therefore have an hybrid approach for waiting on SDONE (interrupt or
   * 1 jiffy timeout if interrupt never comes).
   */
  
  unsigned short pxa2xx_ac97_read(struct snd_ac97 *ac97, unsigned short reg)
  {
  	unsigned short val = -1;
  	volatile u32 *reg_addr;
  
  	mutex_lock(&car_mutex);
  
  	/* set up primary or secondary codec space */
  	if (cpu_is_pxa25x() && reg == AC97_GPIO_STATUS)
  		reg_addr = ac97->num ? &SMC_REG_BASE : &PMC_REG_BASE;
  	else
  		reg_addr = ac97->num ? &SAC_REG_BASE : &PAC_REG_BASE;
  	reg_addr += (reg >> 1);
  
  	/* start read access across the ac97 link */
  	GSR = GSR_CDONE | GSR_SDONE;
  	gsr_bits = 0;
  	val = *reg_addr;
  	if (reg == AC97_GPIO_STATUS)
  		goto out;
  	if (wait_event_timeout(gsr_wq, (GSR | gsr_bits) & GSR_SDONE, 1) <= 0 &&
  	    !((GSR | gsr_bits) & GSR_SDONE)) {
  		printk(KERN_ERR "%s: read error (ac97_reg=%d GSR=%#lx)\n",
  				__func__, reg, GSR | gsr_bits);
  		val = -1;
  		goto out;
  	}
  
  	/* valid data now */
  	GSR = GSR_CDONE | GSR_SDONE;
  	gsr_bits = 0;
  	val = *reg_addr;
  	/* but we've just started another cycle... */
  	wait_event_timeout(gsr_wq, (GSR | gsr_bits) & GSR_SDONE, 1);
  
  out:	mutex_unlock(&car_mutex);
  	return val;
  }
  EXPORT_SYMBOL_GPL(pxa2xx_ac97_read);
  
  void pxa2xx_ac97_write(struct snd_ac97 *ac97, unsigned short reg,
  			unsigned short val)
  {
  	volatile u32 *reg_addr;
  
  	mutex_lock(&car_mutex);
  
  	/* set up primary or secondary codec space */
  	if (cpu_is_pxa25x() && reg == AC97_GPIO_STATUS)
  		reg_addr = ac97->num ? &SMC_REG_BASE : &PMC_REG_BASE;
  	else
  		reg_addr = ac97->num ? &SAC_REG_BASE : &PAC_REG_BASE;
  	reg_addr += (reg >> 1);
  
  	GSR = GSR_CDONE | GSR_SDONE;
  	gsr_bits = 0;
  	*reg_addr = val;
  	if (wait_event_timeout(gsr_wq, (GSR | gsr_bits) & GSR_CDONE, 1) <= 0 &&
  	    !((GSR | gsr_bits) & GSR_CDONE))
  		printk(KERN_ERR "%s: write error (ac97_reg=%d GSR=%#lx)\n",
  				__func__, reg, GSR | gsr_bits);
  
  	mutex_unlock(&car_mutex);
  }
  EXPORT_SYMBOL_GPL(pxa2xx_ac97_write);
  
  #ifdef CONFIG_PXA25x
  static inline void pxa_ac97_warm_pxa25x(void)
  {
  	gsr_bits = 0;
  
  	GCR |= GCR_WARM_RST | GCR_PRIRDY_IEN | GCR_SECRDY_IEN;
  	wait_event_timeout(gsr_wq, gsr_bits & (GSR_PCR | GSR_SCR), 1);
  }
  
  static inline void pxa_ac97_cold_pxa25x(void)
  {
  	GCR &=  GCR_COLD_RST;  /* clear everything but nCRST */
  	GCR &= ~GCR_COLD_RST;  /* then assert nCRST */
  
  	gsr_bits = 0;
  
  	GCR = GCR_COLD_RST;
  	GCR |= GCR_CDONE_IE|GCR_SDONE_IE;
  	wait_event_timeout(gsr_wq, gsr_bits & (GSR_PCR | GSR_SCR), 1);
  }
  #endif
  
  #ifdef CONFIG_PXA27x
  static inline void pxa_ac97_warm_pxa27x(void)
  {
  	gsr_bits = 0;
  
  	/* warm reset broken on Bulverde, so manually keep AC97 reset high */
  	pxa27x_assert_ac97reset(reset_gpio, 1);
  	udelay(10);
  	GCR |= GCR_WARM_RST;
  	pxa27x_assert_ac97reset(reset_gpio, 0);
  	udelay(500);
  }
  
  static inline void pxa_ac97_cold_pxa27x(void)
  {
  	GCR &=  GCR_COLD_RST;  /* clear everything but nCRST */
  	GCR &= ~GCR_COLD_RST;  /* then assert nCRST */
  
  	gsr_bits = 0;
  
  	/* PXA27x Developers Manual section 13.5.2.2.1 */
  	clk_enable(ac97conf_clk);
  	udelay(5);
  	clk_disable(ac97conf_clk);
  	GCR = GCR_COLD_RST;
  	udelay(50);
  }
  #endif
  
  #ifdef CONFIG_PXA3xx
  static inline void pxa_ac97_warm_pxa3xx(void)
  {
  	int timeout = 100;
  
  	gsr_bits = 0;
  
  	/* Can't use interrupts */
  	GCR |= GCR_WARM_RST;
  	while (!((GSR | gsr_bits) & (GSR_PCR | GSR_SCR)) && timeout--)
  		mdelay(1);
  }
  
  static inline void pxa_ac97_cold_pxa3xx(void)
  {
  	int timeout = 1000;
  
  	/* Hold CLKBPB for 100us */
  	GCR = 0;
  	GCR = GCR_CLKBPB;
  	udelay(100);
  	GCR = 0;
  
  	GCR &=  GCR_COLD_RST;  /* clear everything but nCRST */
  	GCR &= ~GCR_COLD_RST;  /* then assert nCRST */
  
  	gsr_bits = 0;
  
  	/* Can't use interrupts on PXA3xx */
  	GCR &= ~(GCR_PRIRDY_IEN|GCR_SECRDY_IEN);
  
  	GCR = GCR_WARM_RST | GCR_COLD_RST;
  	while (!(GSR & (GSR_PCR | GSR_SCR)) && timeout--)
  		mdelay(10);
  }
  #endif
  
  bool pxa2xx_ac97_try_warm_reset(struct snd_ac97 *ac97)
  {
  	unsigned long gsr;
  
  #ifdef CONFIG_PXA25x
  	if (cpu_is_pxa25x())
  		pxa_ac97_warm_pxa25x();
  	else
  #endif
  #ifdef CONFIG_PXA27x
  	if (cpu_is_pxa27x())
  		pxa_ac97_warm_pxa27x();
  	else
  #endif
  #ifdef CONFIG_PXA3xx
  	if (cpu_is_pxa3xx())
  		pxa_ac97_warm_pxa3xx();
  	else
  #endif
  		BUG();
  	gsr = GSR | gsr_bits;
  	if (!(gsr & (GSR_PCR | GSR_SCR))) {
  		printk(KERN_INFO "%s: warm reset timeout (GSR=%#lx)\n",
  				 __func__, gsr);
  
  		return false;
  	}
  
  	return true;
  }
  EXPORT_SYMBOL_GPL(pxa2xx_ac97_try_warm_reset);
  
  bool pxa2xx_ac97_try_cold_reset(struct snd_ac97 *ac97)
  {
  	unsigned long gsr;
  
  #ifdef CONFIG_PXA25x
  	if (cpu_is_pxa25x())
  		pxa_ac97_cold_pxa25x();
  	else
  #endif
  #ifdef CONFIG_PXA27x
  	if (cpu_is_pxa27x())
  		pxa_ac97_cold_pxa27x();
  	else
  #endif
  #ifdef CONFIG_PXA3xx
  	if (cpu_is_pxa3xx())
  		pxa_ac97_cold_pxa3xx();
  	else
  #endif
  		BUG();
  
  	gsr = GSR | gsr_bits;
  	if (!(gsr & (GSR_PCR | GSR_SCR))) {
  		printk(KERN_INFO "%s: cold reset timeout (GSR=%#lx)\n",
  				 __func__, gsr);
  
  		return false;
  	}
  
  	return true;
  }
  EXPORT_SYMBOL_GPL(pxa2xx_ac97_try_cold_reset);
  
  
  void pxa2xx_ac97_finish_reset(struct snd_ac97 *ac97)
  {
  	GCR &= ~(GCR_PRIRDY_IEN|GCR_SECRDY_IEN);
  	GCR |= GCR_SDONE_IE|GCR_CDONE_IE;
  }
  EXPORT_SYMBOL_GPL(pxa2xx_ac97_finish_reset);
  
  static irqreturn_t pxa2xx_ac97_irq(int irq, void *dev_id)
  {
  	long status;
  
  	status = GSR;
  	if (status) {
  		GSR = status;
  		gsr_bits |= status;
  		wake_up(&gsr_wq);
  
  		/* Although we don't use those we still need to clear them
  		   since they tend to spuriously trigger when MMC is used
  		   (hardware bug? go figure)... */
  		if (cpu_is_pxa27x()) {
  			MISR = MISR_EOC;
  			PISR = PISR_EOC;
  			MCSR = MCSR_EOC;
  		}
  
  		return IRQ_HANDLED;
  	}
  
  	return IRQ_NONE;
  }
  
  #ifdef CONFIG_PM
  int pxa2xx_ac97_hw_suspend(void)
  {
  	GCR |= GCR_ACLINK_OFF;
  	clk_disable(ac97_clk);
  	return 0;
  }
  EXPORT_SYMBOL_GPL(pxa2xx_ac97_hw_suspend);
  
  int pxa2xx_ac97_hw_resume(void)
  {
  	clk_enable(ac97_clk);
  	return 0;
  }
  EXPORT_SYMBOL_GPL(pxa2xx_ac97_hw_resume);
  #endif
  
  int __devinit pxa2xx_ac97_hw_probe(struct platform_device *dev)
  {
  	int ret;
  	pxa2xx_audio_ops_t *pdata = dev->dev.platform_data;
  
  	if (pdata) {
  		switch (pdata->reset_gpio) {
  		case 95:
  		case 113:
  			reset_gpio = pdata->reset_gpio;
  			break;
  		case 0:
  			reset_gpio = 113;
  			break;
  		case -1:
  			break;
  		default:
  			dev_err(&dev->dev, "Invalid reset GPIO %d\n",
  				pdata->reset_gpio);
  		}
  	} else {
  		if (cpu_is_pxa27x())
  			reset_gpio = 113;
  	}
  
  	if (cpu_is_pxa27x()) {
  		/* Use GPIO 113 as AC97 Reset on Bulverde */
  		pxa27x_assert_ac97reset(reset_gpio, 0);
  		ac97conf_clk = clk_get(&dev->dev, "AC97CONFCLK");
  		if (IS_ERR(ac97conf_clk)) {
  			ret = PTR_ERR(ac97conf_clk);
  			ac97conf_clk = NULL;
  			goto err_conf;
  		}
  	}
  
  	ac97_clk = clk_get(&dev->dev, "AC97CLK");
  	if (IS_ERR(ac97_clk)) {
  		ret = PTR_ERR(ac97_clk);
  		ac97_clk = NULL;
  		goto err_clk;
  	}
  
  	ret = clk_enable(ac97_clk);
  	if (ret)
  		goto err_clk2;
  
  	ret = request_irq(IRQ_AC97, pxa2xx_ac97_irq, 0, "AC97", NULL);
  	if (ret < 0)
  		goto err_irq;
  
  	return 0;
  
  err_irq:
  	GCR |= GCR_ACLINK_OFF;
  err_clk2:
  	clk_put(ac97_clk);
  	ac97_clk = NULL;
  err_clk:
  	if (ac97conf_clk) {
  		clk_put(ac97conf_clk);
  		ac97conf_clk = NULL;
  	}
  err_conf:
  	return ret;
  }
  EXPORT_SYMBOL_GPL(pxa2xx_ac97_hw_probe);
  
  void pxa2xx_ac97_hw_remove(struct platform_device *dev)
  {
  	GCR |= GCR_ACLINK_OFF;
  	free_irq(IRQ_AC97, NULL);
  	if (ac97conf_clk) {
  		clk_put(ac97conf_clk);
  		ac97conf_clk = NULL;
  	}
  	clk_disable(ac97_clk);
  	clk_put(ac97_clk);
  	ac97_clk = NULL;
  }
  EXPORT_SYMBOL_GPL(pxa2xx_ac97_hw_remove);
  
  MODULE_AUTHOR("Nicolas Pitre");
  MODULE_DESCRIPTION("Intel/Marvell PXA sound library");
  MODULE_LICENSE("GPL");
  
  