Re: [PATCH 15/19] input/ti_am335x_tsc: tiny cleanup

[Jonathan Cameron <jic23@kernel.org>]

On 05/27/2013 08:12 PM, Sebastian Andrzej Siewior wrote:
> Things that can be done to done without using make up:
That causes some amusing images of code with lipstick ;)  'wake up' perhaps?
> - reduce config_inp from 20 elements to 4
>   The loop goes 0…3 so elements 4…19 remain unused.
> - put the shift for analog_line into one line, since config_inp is u32 we
>   don't need to worry about sign extension,
> - check if he DT values are 0…3 as expected
> - replace "err = -EINVAL; goto err" with "return -EINVAL;" as there is no
>   cleanup and this is less code
> - pull out "config[analog_line[i]][0…3];" from the switch case and use
>   magic to the 0…3 correct.
> - since we removed so much lines, spent a few to get
>   "config[an_line][wi_order];" done.
> - get rid of "val32, wires_conf" and assign the values directly. This is
>   just init code but we can still save a few cycles.
> - remove titsc_config_wires() from resume path. ->bit_yn & friends are only
>   written once and not changed so as long as we assume that our DDR will
>   have no biflips we can skip that.
> 
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> ---
>  drivers/input/touchscreen/ti_am335x_tsc.c |  124 ++++++++++++-----------------
>  1 file changed, 51 insertions(+), 73 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c
> index 0dbf3df..96accaa 100644
> --- a/drivers/input/touchscreen/ti_am335x_tsc.c
> +++ b/drivers/input/touchscreen/ti_am335x_tsc.c
> @@ -59,7 +59,7 @@ struct titsc {
>  	unsigned int		bckup_y;
>  	bool			pen_down;
>  	int			steps_to_configure;
> -	int			config_inp[20];
> +	u32			config_inp[4];
>  	int			bit_xp, bit_xn, bit_yp, bit_yn;
>  	int			inp_xp, inp_xn, inp_yp, inp_yn;
>  };
> @@ -115,69 +115,54 @@ static int regbit_map(int val)
>  
>  static int titsc_config_wires(struct titsc *ts_dev)
>  {
> -	int		analog_line[10], wire_order[10];
> -	int		i, temp_bits, err;
> +	u32 analog_line[4];
> +	u32 wire_order[4];
> +	int i, temp_bits;
>  
>  	for (i = 0; i < 4; i++) {
>  		/*
>  		 * Get the order in which TSC wires are attached
>  		 * w.r.t. each of the analog input lines on the EVM.
>  		 */
> -		analog_line[i] = ts_dev->config_inp[i] & 0xF0;
> -		analog_line[i] = analog_line[i] >> 4;
> -
> +		analog_line[i] = (ts_dev->config_inp[i] & 0xF0) >> 4;
>  		wire_order[i] = ts_dev->config_inp[i] & 0x0F;
> +		if (WARN_ON(analog_line[i] > 4))
> +				return -EINVAL;
> +		if (WARN_ON(wire_order[i] > 4))
> +				return -EINVAL;
>  	}
>  
>  	for (i = 0; i < 4; i++) {
> +		int an_line;
> +		int wi_order;
> +
> +		an_line = analog_line[i];
> +		wi_order = wire_order[i];
> +		temp_bits = config[an_line][wi_order];
> +		if (temp_bits == 0)
> +			return -EINVAL;
>  		switch (wire_order[i]) {
>  		case 0:
> -			temp_bits = config[analog_line[i]][0];
> -			if (temp_bits == 0) {
> -				err = -EINVAL;
> -				goto ret;
> -			} else {
> -				ts_dev->bit_xp = regbit_map(temp_bits);
> -				ts_dev->inp_xp = analog_line[i];
> -				break;
> -			}
> +			ts_dev->bit_xp = regbit_map(temp_bits);
> +			ts_dev->inp_xp = analog_line[i];
> +			break;
> +
>  		case 1:
> -			temp_bits = config[analog_line[i]][1];
> -			if (temp_bits == 0) {
> -				err = -EINVAL;
> -				goto ret;
> -			} else {
> -				ts_dev->bit_xn = regbit_map(temp_bits);
> -				ts_dev->inp_xn = analog_line[i];
> -				break;
> -			}
> +			ts_dev->bit_xn = regbit_map(temp_bits);
> +			ts_dev->inp_xn = analog_line[i];
> +			break;
> +
>  		case 2:
> -			temp_bits = config[analog_line[i]][2];
> -			if (temp_bits == 0) {
> -				err = -EINVAL;
> -				goto ret;
> -			} else {
> -				ts_dev->bit_yp = regbit_map(temp_bits);
> -				ts_dev->inp_yp = analog_line[i];
> -				break;
> -			}
> +			ts_dev->bit_yp = regbit_map(temp_bits);
> +			ts_dev->inp_yp = analog_line[i];
> +			break;
>  		case 3:
> -			temp_bits = config[analog_line[i]][3];
> -			if (temp_bits == 0) {
> -				err = -EINVAL;
> -				goto ret;
> -			} else {
> -				ts_dev->bit_yn = regbit_map(temp_bits);
> -				ts_dev->inp_yn = analog_line[i];
> -				break;
> -			}
> +			ts_dev->bit_yn = regbit_map(temp_bits);
> +			ts_dev->inp_yn = analog_line[i];
> +			break;
>  		}
>  	}
> -
>  	return 0;
> -
> -ret:
> -	return err;
>  }
>  
>  static void titsc_step_config(struct titsc *ts_dev)
> @@ -319,7 +304,6 @@ static irqreturn_t titsc_irq(int irq, void *dev)
>  	unsigned int z1, z2, z;
>  	unsigned int fsm;
>  	unsigned int diffx = 0, diffy = 0;
> -	int i;
>  
>  	status = titsc_readl(ts_dev, REG_IRQSTATUS);
>  	if (status & IRQENB_FIFO0THRES) {
> @@ -387,11 +371,10 @@ static irqreturn_t titsc_irq(int irq, void *dev)
>  }
>  
>  static int titsc_parse_dt(struct ti_tscadc_dev *tscadc_dev,
> -					struct titsc *ts_dev)
> +		struct titsc *ts_dev)
>  {
>  	struct device_node *node = tscadc_dev->dev->of_node;
> -	int err, i;
> -	u32 val32, wires_conf[4];
> +	int err;
>  
>  	if (!node)
>  		return -EINVAL;
> @@ -399,34 +382,30 @@ static int titsc_parse_dt(struct ti_tscadc_dev *tscadc_dev,
>  	node = of_get_child_by_name(node, "tsc");
>  	if (!node)
>  		return -EINVAL;
> -	err = of_property_read_u32(node, "ti,wires", &val32);
> +	err = of_property_read_u32(node, "ti,wires", &ts_dev->wires);
>  	if (err < 0)
> -		goto error_ret;
> -	ts_dev->wires = val32;
> -
> -	err = of_property_read_u32(node,
> -			"ti,x-plate-resistance", &val32);
> -	if (err < 0)
> -		goto error_ret;
> -	ts_dev->x_plate_resistance = val32;
> +		return err;
> +	switch (ts_dev->wires) {
> +	case 4:
> +	case 5:
> +	case 8:
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
>  
> -	err = of_property_read_u32(node,
> -			"ti,steps-to-configure", &val32);
> +	err = of_property_read_u32(node, "ti,x-plate-resistance",
> +			&ts_dev->x_plate_resistance);
>  	if (err < 0)
> -		goto error_ret;
> -	ts_dev->steps_to_configure = val32;
> +		return err;
>  
> -	err = of_property_read_u32_array(node, "ti,wire-config",
> -			wires_conf, ARRAY_SIZE(wires_conf));
> +	err = of_property_read_u32(node, "ti,steps-to-configure",
> +			&ts_dev->steps_to_configure);
>  	if (err < 0)
> -		goto error_ret;
> +		return err;
>  
> -	for (i = 0; i < ARRAY_SIZE(wires_conf); i++)
> -		ts_dev->config_inp[i] = wires_conf[i];
> -	return 0;
> -
> -error_ret:
> -	return err;
> +	return of_property_read_u32_array(node, "ti,wire-config",
> +			ts_dev->config_inp, ARRAY_SIZE(ts_dev->config_inp));
>  }
>  
>  /*
> @@ -545,7 +524,6 @@ static int titsc_resume(struct device *dev)
>  				0x00);
>  		titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
>  	}
> -	titsc_config_wires(ts_dev);
>  	titsc_step_config(ts_dev);
>  	titsc_writel(ts_dev, REG_FIFO0THR,
>  			ts_dev->steps_to_configure);
>