Re: [gentoo-ppc-user] pbbuttonsd question

[Konstantin V. Gavrilenko]

Here is an answer from Ben, I still have to test it myself.



Benjamin Herrenschmidt wrote:
> On Tue, 2006-05-30 at 21:09 +0100, Konstantin V. Gavrilenko wrote:
> SNIP <


> Does this help ?
>
> Ben.
>
> ------
> From: Linux Kernel Mailing List <linux-kernel@×××××××××××.org>
> To: git-commits-head@×××××××××××.org
> Subject: [PATCH] powermac: Fix i2c on keywest based chips
> Date: Sun, 23 Apr 2006 17:11:14 GMT
>
> commit 60162e498e220d1f03bbee5bac0a9ddd6de60ae7
> tree 8cbcbea6060eb2b9f7d39784385efdfc6e947b52
> parent 28897731318dc8f63f683eed9091e446916ad706
> author Benjamin Herrenschmidt <benh@×××××××××××××××.org> Tue, 18 Apr
2006 14:11:53 +1000
> committer Paul Mackerras <paulus@×××××.org> Fri, 21 Apr 2006 22:29:46
+1000
>
> [PATCH] powermac: Fix i2c on keywest based chips
>
> The new i2c implementation for PowerMac has a regression that causes the
> hardware to go out of state when probing non-existent devices. While
> fixing that, I also found & fixed a couple of other corner cases. This
> fixes booting with a pbbuttons version that scans the i2c bus for an LMU
> controller among others. Tested on a dual G5 with thermal control (which
> has heavy i2c activity) with no problem so far.
>
> Signed-off-by: Benjamin Herrenschmidt <benh@×××××××××××××××.org>
> Signed-off-by: Paul Mackerras <paulus@×××××.org>
>
>  arch/powerpc/platforms/powermac/low_i2c.c |   78
+++++++++++++-----------------
>  1 files changed, 35 insertions(+), 43 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powermac/low_i2c.c
b/arch/powerpc/platforms/powermac/low_i2c.c
> index e14f9ac..df2343e 100644
> --- a/arch/powerpc/platforms/powermac/low_i2c.c
> +++ b/arch/powerpc/platforms/powermac/low_i2c.c
> @@ -231,6 +231,14 @@ static u8 kw_i2c_wait_interrupt(struct p
>  	return isr;
>  }
>
> +static void kw_i2c_do_stop(struct pmac_i2c_host_kw *host, int result)
> +{
> +	kw_write_reg(reg_control, KW_I2C_CTL_STOP);
> +	host->state = state_stop;
> +	host->result = result;
> +}
> +
> +
>  static void kw_i2c_handle_interrupt(struct pmac_i2c_host_kw *host, u8
isr)
>  {
>  	u8 ack;
> @@ -246,42 +254,36 @@ static void kw_i2c_handle_interrupt(stru
>  	}
>
>  	if (isr == 0) {
> +		printk(KERN_WARNING "low_i2c: Timeout in i2c transfer"
> +		       " on keywest !\n");
>  		if (host->state != state_stop) {
> -			DBG_LOW("KW: Timeout !\n");
> -			host->result = -EIO;
> -			goto stop;
> -		}
> -		if (host->state == state_stop) {
> -			ack = kw_read_reg(reg_status);
> -			if (ack & KW_I2C_STAT_BUSY)
> -				kw_write_reg(reg_status, 0);
> -			host->state = state_idle;
> -			kw_write_reg(reg_ier, 0x00);
> -			if (!host->polled)
> -				complete(&host->complete);
> +			kw_i2c_do_stop(host, -EIO);
> +			return;
>  		}
> +		ack = kw_read_reg(reg_status);
> +		if (ack & KW_I2C_STAT_BUSY)
> +			kw_write_reg(reg_status, 0);
> +		host->state = state_idle;
> +		kw_write_reg(reg_ier, 0x00);
> +		if (!host->polled)
> +			complete(&host->complete);
>  		return;
>  	}
>
>  	if (isr & KW_I2C_IRQ_ADDR) {
>  		ack = kw_read_reg(reg_status);
>  		if (host->state != state_addr) {
> -			kw_write_reg(reg_isr, KW_I2C_IRQ_ADDR);
>  			WRONG_STATE("KW_I2C_IRQ_ADDR");
> -			host->result = -EIO;
> -			goto stop;
> +			kw_i2c_do_stop(host, -EIO);
>  		}
>  		if ((ack & KW_I2C_STAT_LAST_AAK) == 0) {
> -			host->result = -ENODEV;
> -			DBG_LOW("KW: NAK on address\n");
> +			host->result = -ENXIO;
>  			host->state = state_stop;
> -			return;
> +			DBG_LOW("KW: NAK on address\n");
>  		} else {
> -			if (host->len == 0) {
> -				kw_write_reg(reg_isr, KW_I2C_IRQ_ADDR);
> -				goto stop;
> -			}
> -			if (host->rw) {
> +			if (host->len == 0)
> +				kw_i2c_do_stop(host, 0);
> +			else if (host->rw) {
>  				host->state = state_read;
>  				if (host->len > 1)
>  					kw_write_reg(reg_control,
> @@ -308,25 +310,19 @@ static void kw_i2c_handle_interrupt(stru
>  			ack = kw_read_reg(reg_status);
>  			if ((ack & KW_I2C_STAT_LAST_AAK) == 0) {
>  				DBG_LOW("KW: nack on data write\n");
> -				host->result = -EIO;
> -				goto stop;
> +				host->result = -EFBIG;
> +				host->state = state_stop;
>  			} else if (host->len) {
>  				kw_write_reg(reg_data, *(host->data++));
>  				host->len--;
> -			} else {
> -				kw_write_reg(reg_control, KW_I2C_CTL_STOP);
> -				host->state = state_stop;
> -				host->result = 0;
> -			}
> -			kw_write_reg(reg_isr, KW_I2C_IRQ_DATA);
> +			} else
> +				kw_i2c_do_stop(host, 0);
>  		} else {
> -			kw_write_reg(reg_isr, KW_I2C_IRQ_DATA);
>  			WRONG_STATE("KW_I2C_IRQ_DATA");
> -			if (host->state != state_stop) {
> -				host->result = -EIO;
> -				goto stop;
> -			}
> +			if (host->state != state_stop)
> +				kw_i2c_do_stop(host, -EIO);
>  		}
> +		kw_write_reg(reg_isr, KW_I2C_IRQ_DATA);
>  	}
>
>  	if (isr & KW_I2C_IRQ_STOP) {
> @@ -340,14 +336,10 @@ static void kw_i2c_handle_interrupt(stru
>  			complete(&host->complete);
>  	}
>
> +	/* Below should only happen in manual mode which we don't use ... */
>  	if (isr & KW_I2C_IRQ_START)
>  		kw_write_reg(reg_isr, KW_I2C_IRQ_START);
>
> -	return;
> - stop:
> -	kw_write_reg(reg_control, KW_I2C_CTL_STOP);
> -	host->state = state_stop;
> -	return;
>  }
>
>  /* Interrupt handler */
> @@ -544,11 +536,11 @@ static struct pmac_i2c_host_kw *__init k
>  		return NULL;
>  	}
>
> -	/* Make sure IRA is disabled */
> +	/* Make sure IRQ is disabled */
>  	kw_write_reg(reg_ier, 0);
>
>  	/* Request chip interrupt */
> -	if (request_irq(host->irq, kw_i2c_irq, SA_SHIRQ, "keywest i2c", host))
> +	if (request_irq(host->irq, kw_i2c_irq, 0, "keywest i2c", host))
>  		host->irq = NO_IRQ;
>
>  	printk(KERN_INFO "KeyWest i2c @0x%08x irq %d %s\n",
> -
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-- 
Respectfully,
Konstantin V. Gavrilenko

Managing Director
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