Re: [RFC PATCH 78/71] ncr5380: Add support for HP 53C400A-based cards (C2502)

[Finn Thain]

On Sat, 5 Dec 2015, Ondrej Zary wrote:

> HP C2502 cards (based on 53C400A chips) use different magic numbers for 
> software-based I/O address configuration than other cards. The 
> configuration is also extended to allow setting the IRQ.
> 
> Move the configuration to a new function magic_configure() and move 
> magic the magic numbers into an array. Add new magic numbers for these 
> HP cards and hp_53c400a module parameter to use them.
> 
> Tested with HP C2502 and DTCT-436P.
> 
> Signed-off-by: Ondrej Zary <linux@xxxxxxxxxxxxxxxxxxxx>
> ---
>  drivers/scsi/g_NCR5380.c |   69 +++++++++++++++++++++++++++++++++++-----------
>  drivers/scsi/g_NCR5380.h |    1 +
>  2 files changed, 54 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/scsi/g_NCR5380.c b/drivers/scsi/g_NCR5380.c
> index 38579b0..52110e0 100644
> --- a/drivers/scsi/g_NCR5380.c
> +++ b/drivers/scsi/g_NCR5380.c
> @@ -80,6 +80,7 @@ static int ncr_5380;
>  static int ncr_53c400;
>  static int ncr_53c400a;
>  static int dtc_3181e;
> +static int hp_53c400a;
>  
>  static struct override {
>  	NCR5380_map_type NCR5380_map_name;
> @@ -225,6 +226,26 @@ static int __init do_DTC3181E_setup(char *str)
>  
>  #endif
>  
> +#ifndef SCSI_G_NCR5380_MEM
> +static void magic_configure(int idx, u8 irq, u8 magic[])
> +{
> +	u8 cfg = 0;
> +
> +	outb(magic[0], 0x779);
> +	outb(magic[1], 0x379);
> +	outb(magic[2], 0x379);
> +	outb(magic[3], 0x379);
> +	outb(magic[4], 0x379);
> +
> +	/* allowed IRQs for HP 53C400A */
> +	if (irq != 2 && irq != 3 && irq != 4 && irq != 5 && irq != 7)
> +		irq = 0;
> +	if (idx >= 0 && idx <= 7)
> +		cfg = 0x80 | idx | (irq << 4);
> +	outb(cfg, 0x379);
> +}
> +#endif
> +
>  /**
>   * 	generic_NCR5380_detect	-	look for NCR5380 controllers
>   *	@tpnt: the scsi template
> @@ -241,8 +262,9 @@ static int __init generic_NCR5380_detect(struct scsi_host_template *tpnt)
>  	static int current_override;
>  	int count;
>  	unsigned int *ports;
> +	u8 *magic;
>  #ifndef SCSI_G_NCR5380_MEM
> -	int i;
> +	int i, port_idx;
>  	unsigned long region_size = 16;
>  #endif
>  	static unsigned int __initdata ncr_53c400a_ports[] = {
> @@ -251,6 +273,12 @@ static int __init generic_NCR5380_detect(struct scsi_host_template *tpnt)
>  	static unsigned int __initdata dtc_3181e_ports[] = {
>  		0x220, 0x240, 0x280, 0x2a0, 0x2c0, 0x300, 0x320, 0x340, 0
>  	};
> +	static u8 ncr_53c400a_magic[] __initdata = {
> +		0x59, 0xb9, 0xc5, 0xae, 0xa6
> +	};
> +	static u8 hp_53c400a_magic[] __initdata = {
> +		0x0f, 0x22, 0xf0, 0x20, 0x80
> +	};

Magic numbers that are clearly labeled as such tells me that no-one can 
say what they actually mean... is that right?

>  	int flags;
>  	struct Scsi_Host *instance;
>  	struct NCR5380_hostdata *hostdata;
> @@ -273,6 +301,8 @@ static int __init generic_NCR5380_detect(struct scsi_host_template *tpnt)
>  		overrides[0].board = BOARD_NCR53C400A;
>  	else if (dtc_3181e)
>  		overrides[0].board = BOARD_DTC3181E;
> +	else if (hp_53c400a)
> +		overrides[0].board = BOARD_HP53C400A;
>  #ifndef SCSI_G_NCR5380_MEM
>  	if (!current_override && isapnp_present()) {
>  		struct pnp_dev *dev = NULL;
> @@ -323,13 +353,21 @@ static int __init generic_NCR5380_detect(struct scsi_host_template *tpnt)
>  			flags = FLAG_NO_PSEUDO_DMA;
>  #endif
>  			break;
> +		case BOARD_HP53C400A:
> +			flags = FLAG_NO_DMA_FIXUP;
> +			ports = ncr_53c400a_ports;
> +			magic = hp_53c400a_magic;

Nice! A new board.

> +			overrides[current_override].board = BOARD_NCR53C400A;

Do you rewrite overrides[current_override].board in order to avoid another 
term in a long conditional expression? Don't you find that confusing? Why 
not consistently use switch statements when we have to test 
overrides[current_override].board?

> +			break;
>  		case BOARD_NCR53C400A:
>  			flags = FLAG_NO_DMA_FIXUP;
>  			ports = ncr_53c400a_ports;
> +			magic = ncr_53c400a_magic;
>  			break;
>  		case BOARD_DTC3181E:
>  			flags = FLAG_NO_DMA_FIXUP;
>  			ports = dtc_3181e_ports;
> +			magic = ncr_53c400a_magic;
>  			break;
>  		}
>  
> @@ -338,12 +376,7 @@ static int __init generic_NCR5380_detect(struct scsi_host_template *tpnt)
>  			/* wakeup sequence for the NCR53C400A and DTC3181E */
>  
>  			/* Disable the adapter and look for a free io port */
> -			outb(0x59, 0x779);
> -			outb(0xb9, 0x379);
> -			outb(0xc5, 0x379);
> -			outb(0xae, 0x379);
> -			outb(0xa6, 0x379);
> -			outb(0x00, 0x379);
> +			magic_configure(-1, 0, magic);
>  
>  			if (overrides[current_override].NCR5380_map_name != PORT_AUTO)
>  				for (i = 0; ports[i]; i++) {
> @@ -362,17 +395,14 @@ static int __init generic_NCR5380_detect(struct scsi_host_template *tpnt)
>  				}
>  			if (ports[i]) {
>  				/* At this point we have our region reserved */
> -				outb(0x59, 0x779);
> -				outb(0xb9, 0x379);
> -				outb(0xc5, 0x379);
> -				outb(0xae, 0x379);
> -				outb(0xa6, 0x379);
> -				outb(0x80 | i, 0x379);	/* set io port to be used */
> +				magic_configure(i, 0, magic); /* no IRQ yet */
>  				outb(0xc0, ports[i] + 9);
> -				if (inb(ports[i] + 9) != 0x80)
> +				if (inb(ports[i] + 9) != 0x80) {
>  					continue;
> -				else
> +				} else {
>  					overrides[current_override].NCR5380_map_name = ports[i];
> +					port_idx = i;
> +				}
>  			} else
>  				continue;
>  		}
> @@ -464,12 +494,18 @@ static int __init generic_NCR5380_detect(struct scsi_host_template *tpnt)
>  		if (instance->irq == 255)
>  			instance->irq = NO_IRQ;
>  
> -		if (instance->irq != NO_IRQ)
> +		if (instance->irq != NO_IRQ) {
> +#ifndef SCSI_G_NCR5380_MEM
> +			/* set IRQ for HP 53C400A */
> +			if (magic == hp_53c400a_magic)
> +				magic_configure(port_idx, instance->irq, magic);
> +#endif

This would be better done earlier. We need to determine and assign the 
instance->irq value before NCR5380_init() in order to fix the irq number 
printed in the log messages when the driver starts. But that should 
probably be a separate patch...

>  			if (request_irq(instance->irq, generic_NCR5380_intr,
>  					0, "NCR5380", instance)) {
>  				printk(KERN_WARNING "scsi%d : IRQ%d not free, interrupts disabled\n", instance->host_no, instance->irq);
>  				instance->irq = NO_IRQ;
>  			}
> +		}
>  
>  		if (instance->irq == NO_IRQ) {
>  			printk(KERN_INFO "scsi%d : interrupts not enabled. for better interactive performance,\n", instance->host_no);
> @@ -763,6 +799,7 @@ module_param(ncr_5380, int, 0);
>  module_param(ncr_53c400, int, 0);
>  module_param(ncr_53c400a, int, 0);
>  module_param(dtc_3181e, int, 0);
> +module_param(hp_53c400a, int, 0);
>  MODULE_LICENSE("GPL");
>  
>  #if !defined(SCSI_G_NCR5380_MEM) && defined(MODULE)
> diff --git a/drivers/scsi/g_NCR5380.h b/drivers/scsi/g_NCR5380.h
> index b3936aa..369ab9e 100644
> --- a/drivers/scsi/g_NCR5380.h
> +++ b/drivers/scsi/g_NCR5380.h
> @@ -89,6 +89,7 @@
>  #define BOARD_NCR53C400	1
>  #define BOARD_NCR53C400A 2
>  #define BOARD_DTC3181E	3
> +#define BOARD_HP53C400A 4
>  
>  #endif /* GENERIC_NCR5380_H */
>  
> 

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