Add AHCI attachment for Allwinner A10/A20 SoCs.

[loos]

Summary

The Allwinner SoC has an ahci device on its internal main bus rather
than the PCI bus. This SoC is somewhat underdocumented, and its SATA
controller is no exception. The methods to support this chip were
harvested from the Linux Allwinner SDK, and then constants invented to
describe what's going on based on low-level constants contained in the
SATA standard and guess work. The AHCI driver isn't (yet) supported on
Allwinner due to well known deficiencies in config.

[• ian]

sys/arm/allwinner/a10_ahci.c

165

typo: nout

315

something looks wrong with indentation here, unless it's a website artifact

376

shouldn't this be on simplebus? it's got a probe routine that implies it should

[ganbold]

sys/arm/allwinner/a10_ahci.c

3

s/,/./ in email

269

Style, insert empty line here?

[mav]

To me it does not look like a good place to do PHY initialization and especially some calibration on AHCI driver attach. What happen if due to command timeout AHCI driver will request another PHY reset or device will be hot-plugged? I understand that present code is less invasive, but may be adding pointer to some external reset method could be not so dirty?

[imp]

In D737#5, @mav wrote:

To me it does not look like a good place to do PHY initialization and especially some calibration on AHCI driver attach. What happen if due to command timeout AHCI driver will request another PHY reset or device will be hot-plugged? I understand that present code is less invasive, but may be adding pointer to some external reset method could be not so dirty?

Generally, I agree with this. We need to move in that direction. The code I started with was somewhat dirty and hacky with minimal comments to know for sure what's going on. Once we have this working robustly for the normal "boot it and the drive is just there and working case" we can refine this based on experimentation with disconnect scenarios. It may be the guesses about what's going on aren't quite right.

[loos]

Ok, looks like I need this to update this revision.

[loos]

Update the code to match -head changes and add the missing channel start magic.

This version fixes the problems noticed by ian and ganbold and adds the missing
magic to start the AHCI channel.

AHCI has to be changed to call the channel start callback.

Also fixes the AHCI IRQ setup and add the AHCI_Q_NOPMP quirk (necessary for
correct operation).

Tested on Cubieboard 2 and Banana Pi.

[loos]

All fixed.

[imp]

looks good to me, modulo one minor nit.

sys/arm/allwinner/a10_ahci.c

2

looks like you reworked this a bit, so put both your name and mine with 2015 copyrights.

[andrew]

sys/arm/allwinner/a10_ahci.c

268–269

What are these magic values?

356–368

Are these needed?

[imp]

sys/arm/allwinner/a10_ahci.c

268–269

They come from the Linux driver, which is even worse about naming them in meaningful ways. There's no real documentation apart from that junk for this stuff.
The upper bits of this register evidentally are implementation defined.

[mav]

Looks fine to me.

[andrew]

sys/arm/allwinner/a10_ahci.c

268–269

Ok, it would pay to add a comment to say we don't know the meaning of these numbers, but they came from Linux.

[loos]

Committed in r285090.

Thanks to everyone.

sys/arm/allwinner/a10_ahci.c

for (; cs < ce; cs++) {
                 buffer += c;
         }
         buffer += '\'';
 
         return buffer;
 }
 
 void
-config::expand_one(const char *&src, string &dst)
+config::expand_one(const char *&src, string &dst, bool is_shell)
 {
         int count;
         string buffer;
 
         src++;
         // $$ -> $
         if (*src == '$') {
                 dst += *src++;
if (!isalpha(*src) && *src != '_' && *src != '-' && *src != '*') {
                 dst += *src++;
                 return;
         }
 
         // $var -> replace with value
         do {
                 buffer += *src++;
         } while (is_id_char(*src));
-        dst.append(shell_quote(get_variable(buffer)));
+        dst.append(is_shell ? shell_quote(get_variable(buffer)) : get_variable(buffer));
 }
 
 const string
 config::expand_string(const char *src, const char *prepend, const char *append)
 {
         const char *var_at;
         string dst;
 
config::expand_string(const char *src, const char *prepend, const char *append)
         for (;;) {
                 var_at = strchr(src, '$');
                 if (var_at == NULL) {
                         dst.append(src);
                         break;
                 }
                 dst.append(src, var_at - src);
                 src = var_at;
-                expand_one(src, dst);
+                expand_one(src, dst, prepend == NULL);
         }
 
         if (append != NULL)
                 dst.append(append);
 
         return (dst);
 }
 

sys/arm/allwinner/a10_clk.h

for (; cs < ce; cs++) {
                 buffer += c;
         }
         buffer += '\'';
 
         return buffer;
 }
 
 void
-config::expand_one(const char *&src, string &dst)
+config::expand_one(const char *&src, string &dst, bool is_shell)
 {
         int count;
         string buffer;
 
         src++;
         // $$ -> $
         if (*src == '$') {
                 dst += *src++;
if (!isalpha(*src) && *src != '_' && *src != '-' && *src != '*') {
                 dst += *src++;
                 return;
         }
 
         // $var -> replace with value
         do {
                 buffer += *src++;
         } while (is_id_char(*src));
-        dst.append(shell_quote(get_variable(buffer)));
+        dst.append(is_shell ? shell_quote(get_variable(buffer)) : get_variable(buffer));
 }
 
 const string
 config::expand_string(const char *src, const char *prepend, const char *append)
 {
         const char *var_at;
         string dst;
 
config::expand_string(const char *src, const char *prepend, const char *append)
         for (;;) {
                 var_at = strchr(src, '$');
                 if (var_at == NULL) {
                         dst.append(src);
                         break;
                 }
                 dst.append(src, var_at - src);
                 src = var_at;
-                expand_one(src, dst);
+                expand_one(src, dst, prepend == NULL);
         }
 
         if (append != NULL)
                 dst.append(append);
 
         return (dst);
 }
 

sys/arm/allwinner/a10_clk.c

for (; cs < ce; cs++) {
                 buffer += c;
         }
         buffer += '\'';
 
         return buffer;
 }
 
 void
-config::expand_one(const char *&src, string &dst)
+config::expand_one(const char *&src, string &dst, bool is_shell)
 {
         int count;
         string buffer;
 
         src++;
         // $$ -> $
         if (*src == '$') {
                 dst += *src++;
if (!isalpha(*src) && *src != '_' && *src != '-' && *src != '*') {
                 dst += *src++;
                 return;
         }
 
         // $var -> replace with value
         do {
                 buffer += *src++;
         } while (is_id_char(*src));
-        dst.append(shell_quote(get_variable(buffer)));
+        dst.append(is_shell ? shell_quote(get_variable(buffer)) : get_variable(buffer));
 }
 
 const string
 config::expand_string(const char *src, const char *prepend, const char *append)
 {
         const char *var_at;
         string dst;
 
config::expand_string(const char *src, const char *prepend, const char *append)
         for (;;) {
                 var_at = strchr(src, '$');
                 if (var_at == NULL) {
                         dst.append(src);
                         break;
                 }
                 dst.append(src, var_at - src);
                 src = var_at;
-                expand_one(src, dst);
+                expand_one(src, dst, prepend == NULL);
         }
 
         if (append != NULL)
                 dst.append(append);
 
         return (dst);
 }
 

sys/arm/allwinner/files.allwinner

for (; cs < ce; cs++) {
                 buffer += c;
         }
         buffer += '\'';
 
         return buffer;
 }
 
 void
-config::expand_one(const char *&src, string &dst)
+config::expand_one(const char *&src, string &dst, bool is_shell)
 {
         int count;
         string buffer;
 
         src++;
         // $$ -> $
         if (*src == '$') {
                 dst += *src++;
if (!isalpha(*src) && *src != '_' && *src != '-' && *src != '*') {
                 dst += *src++;
                 return;
         }
 
         // $var -> replace with value
         do {
                 buffer += *src++;
         } while (is_id_char(*src));
-        dst.append(shell_quote(get_variable(buffer)));
+        dst.append(is_shell ? shell_quote(get_variable(buffer)) : get_variable(buffer));
 }
 
 const string
 config::expand_string(const char *src, const char *prepend, const char *append)
 {
         const char *var_at;
         string dst;
 
config::expand_string(const char *src, const char *prepend, const char *append)
         for (;;) {
                 var_at = strchr(src, '$');
                 if (var_at == NULL) {
                         dst.append(src);
                         break;
                 }
                 dst.append(src, var_at - src);
                 src = var_at;
-                expand_one(src, dst);
+                expand_one(src, dst, prepend == NULL);
         }
 
         if (append != NULL)
                 dst.append(append);
 
         return (dst);
 }