[src/thorpej-i2c-spi-conf]: src/sys/dev/spi Use spi_compatible_match().

[thorpej <thorpej%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/7c9784a24f42
branches:  thorpej-i2c-spi-conf
changeset: 1020830:7c9784a24f42
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Wed May 19 03:33:33 2021 +0000

description:
Use spi_compatible_match().

diffstat:

 sys/dev/spi/mcp48x1.c |  116 ++++++++++++++++++++++++++++++++++---------------
 1 files changed, 79 insertions(+), 37 deletions(-)

diffs (167 lines):

diff -r 181b2a04530a -r 7c9784a24f42 sys/dev/spi/mcp48x1.c
--- a/sys/dev/spi/mcp48x1.c     Wed May 19 03:32:27 2021 +0000
+++ b/sys/dev/spi/mcp48x1.c     Wed May 19 03:33:33 2021 +0000
@@ -1,4 +1,4 @@
-/*      $NetBSD: mcp48x1.c,v 1.1 2014/02/25 20:09:37 rkujawa Exp $ */
+/*      $NetBSD: mcp48x1.c,v 1.1.54.1 2021/05/19 03:33:33 thorpej Exp $ */
 
 /*-
  * Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: mcp48x1.c,v 1.1 2014/02/25 20:09:37 rkujawa Exp $");
+__KERNEL_RCSID(0, "$NetBSD: mcp48x1.c,v 1.1.54.1 2021/05/19 03:33:33 thorpej Exp $");
 
 /* 
  * Driver for Microchip MCP4801/MCP4811/MCP4821 DAC. 
@@ -57,7 +57,7 @@
 #define MCP48X1DAC_DATA                __BITS(11,0)    /* data */
 
 struct mcp48x1dac_model {
-       const char *name;
+       u_int name;
        uint8_t resolution;
        uint8_t shift;                  /* data left shift during write */
 };
@@ -66,7 +66,7 @@
        device_t sc_dev;
        struct spi_handle *sc_sh;
 
-       struct mcp48x1dac_model *sc_dm; /* struct describing DAC model */
+       const struct mcp48x1dac_model *sc_dm;
 
        uint16_t sc_dac_data;
        bool sc_dac_gain;
@@ -93,55 +93,97 @@
 CFATTACH_DECL_NEW(mcp48x1dac, sizeof(struct mcp48x1dac_softc),
     mcp48x1dac_match, mcp48x1dac_attach, NULL, NULL);
 
-static struct mcp48x1dac_model mcp48x1_models[] = {
-       {
-               .name = "MCP4801",
-               .resolution = 8,
-               .shift = 4
-       },
-       {
-               .name = "MCP4811",
-               .resolution = 10,
-               .shift = 2
-       },
-       {
-               .name = "MCP4821",
-               .resolution = 12,
-               .shift = 0
-       }
+static const struct mcp48x1dac_model mcp4801 = {
+       .name = 4801,
+       .resolution = 8,
+       .shift = 4
+};
+
+static const struct mcp48x1dac_model mcp4811 = {
+       .name = 4811,
+       .resolution = 10,
+       .shift = 2
+};
+
+static const struct mcp48x1dac_model mcp4821 = {
+       .name = 4821,
+       .resolution = 12,
+       .shift = 0
+};
+
+static const struct device_compatible_entry compat_data[] = {
+       { .compat = "microchip,mcp4801",        .data = &mcp4801 },
+       { .compat = "microchip,mcp4811",        .data = &mcp4811 },
+       { .compat = "microchip,mcp4821",        .data = &mcp4821 },
+       DEVICE_COMPAT_EOL
 };
 
+static const struct mcp48x1dac_model *
+mcp48x1dac_lookup(const struct spi_attach_args *sa, const cfdata_t cf)
+{
+       const struct device_compatible_entry *dce;
+
+       if (sa->sa_clist != NULL) {
+               dce = device_compatible_lookup_strlist(sa->sa_clist,
+                   sa->sa_clist_size, compat_data);
+               if (dce == NULL) {
+                       return NULL;
+               }
+               return dce->data;
+       } else {
+               const struct mcp48x1dac_model *model;
+
+               for (dce = compat_data; dce->compat != NULL; dce++) {
+                       model = dce->data;
+                       if (model->name == cf->cf_flags) {
+                               return model;
+                       }
+               }
+               return NULL;
+       }
+}
 
 static int
 mcp48x1dac_match(device_t parent, cfdata_t cf, void *aux)
 {
        struct spi_attach_args *sa = aux;
-
-       /* MCP48x1 is a write-only device, so no way to detect it! */
+       int rv;
 
-       if (spi_configure(sa->sa_handle, SPI_MODE_0, 20000000))
-               return 0;
+       rv = spi_compatible_match(sa, cf, compat_data);
+       if (rv != 0) {
+               /*
+                * If we're doing indorect config, the user must
+                * have specified the correct model.
+                */
+               if (sa->sa_clist == NULL && mcp48x1dac_lookup(sa, cf) == NULL) {
+                       return 0;
+               }
 
-       return 1;
+               /* configure for 20MHz */
+               if (spi_configure(sa->sa_handle, SPI_MODE_0, 20000000))
+                       return 0;
+       }
+
+       return rv;
 }
 
 static void
 mcp48x1dac_attach(device_t parent, device_t self, void *aux)
 {
-       struct mcp48x1dac_softc *sc;
-       struct spi_attach_args *sa;
-       int cf_flags;
+       struct mcp48x1dac_softc *sc = device_private(self);
+       struct spi_attach_args *sa = aux;
+       const struct mcp48x1dac_model *model;
+
+       sc->sc_dev = self;
+       sc->sc_sh = sa->sa_handle;
+
+       model = mcp48x1dac_lookup(sa, device_cfdata(self));
+       KASSERT(model != NULL);
+
+       sc->sc_dm = model;
 
        aprint_naive(": Digital to Analog converter\n");        
-       aprint_normal(": MCP48x1 DAC\n");
-
-       sa = aux;
-       sc = device_private(self);
-       sc->sc_dev = self;
-       sc->sc_sh = sa->sa_handle;
-       cf_flags = device_cfdata(sc->sc_dev)->cf_flags;
-
-       sc->sc_dm = &mcp48x1_models[cf_flags]; /* flag value defines model */
+       aprint_normal(": MCP%u DAC\n", model->name);
 
        if(!mcp48x1dac_envsys_attach(sc)) {
                aprint_error_dev(sc->sc_dev, "failed to attach envsys\n");