[src/trunk]: src/sys/dev/i2c Avoid creating a full temporary softc struct on ...

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

details:   https://anonhg.NetBSD.org/src/rev/6376286ddf46
branches:  trunk
changeset: 973290:6376286ddf46
user:      martin <martin%NetBSD.org@localhost>
date:      Fri Jun 26 10:06:57 2020 +0000

description:
Avoid creating a full temporary softc struct on the stack.

diffstat:

 sys/dev/i2c/adm1026.c |  62 +++++++++++++++++++++++++++-----------------------
 1 files changed, 34 insertions(+), 28 deletions(-)

diffs (159 lines):

diff -r 341d60d266c5 -r 6376286ddf46 sys/dev/i2c/adm1026.c
--- a/sys/dev/i2c/adm1026.c     Fri Jun 26 08:42:27 2020 +0000
+++ b/sys/dev/i2c/adm1026.c     Fri Jun 26 10:06:57 2020 +0000
@@ -28,7 +28,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: adm1026.c,v 1.7 2019/12/23 02:25:28 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: adm1026.c,v 1.8 2020/06/26 10:06:57 martin Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -98,7 +98,7 @@
 };
 
 static int adm1026_match(device_t, cfdata_t, void *);
-static int adm1026_ident(struct adm1026_softc *, int);
+static int adm1026_ident(i2c_tag_t, i2c_addr_t, int, uint8_t*);
 static void adm1026_attach(device_t, device_t, void *);
 static int adm1026_detach(device_t, int);
 bool adm1026_pmf_suspend(device_t, const pmf_qual_t *);
@@ -113,11 +113,18 @@
 static void adm1026_read_temp(struct adm1026_softc *sc, envsys_data_t *edata);
 static void adm1026_read_volt(struct adm1026_softc *sc, envsys_data_t *edata);
 
-static int adm1026_read_reg(struct adm1026_softc *sc,
-    uint8_t reg, uint8_t *val);
+static int adm1026_read_reg_int(i2c_tag_t, i2c_addr_t,
+    uint8_t reg, bool multi_read, uint8_t *val);
 static int adm1026_write_reg(struct adm1026_softc *sc,
     uint8_t reg, uint8_t val);
 
+static inline int
+adm1026_read_reg(struct adm1026_softc *sc, uint8_t reg, uint8_t *val)
+{
+       return adm1026_read_reg_int(sc->sc_tag, sc->sc_address, reg,
+           sc->sc_multi_read, val);
+}
+
 CFATTACH_DECL_NEW(adm1026hm, sizeof(struct adm1026_softc),
        adm1026_match, adm1026_attach, adm1026_detach, NULL);
 
@@ -130,37 +137,35 @@
 adm1026_match(device_t parent, cfdata_t cf, void *aux)
 {
        struct i2c_attach_args *ia = aux;
-       struct adm1026_softc sc;        /* For chip ident */
        int match_result;
-
-       sc.sc_tag = ia->ia_tag;
-       sc.sc_address = ia->ia_addr;
+       uint8_t rev;
 
        if (iic_use_direct_match(ia, cf, compat_data, &match_result))
                return match_result;
 
-       if (ia->ia_addr == ADM1026_ADDR1 && adm1026_ident(&sc, 1))
+       if (ia->ia_addr == ADM1026_ADDR1
+           && adm1026_ident(ia->ia_tag, ia->ia_addr, 1, &rev))
                return I2C_MATCH_ADDRESS_AND_PROBE;
 
        return 0;
 }
 
 static int
-adm1026_ident(struct adm1026_softc *sc, int probe_only)
+adm1026_ident(i2c_tag_t tag, i2c_addr_t addr, int probe_only, uint8_t *rev)
 {
        uint8_t val;
        int err;
 
        /* Manufacturer ID and revision/stepping */
-       err = adm1026_read_reg(sc, ADM1026_ID, &val);
+       err = adm1026_read_reg_int(tag, addr, ADM1026_ID, false, &val);
        if (err || val != ADM1026_MANF_ID) {
                if (!probe_only)
                        aprint_verbose("adm1026_ident: "
                            "manufacturer ID invalid or missing\n");
                return 0;
        }
-       err = adm1026_read_reg(sc, ADM1026_REV, &sc->sc_rev);
-       if (err || ADM1026_REVISION(sc->sc_rev) != ADM1026_MANF_REV) {
+       err = adm1026_read_reg_int(tag, addr, ADM1026_REV, false, rev);
+       if (err || ADM1026_REVISION(*rev) != ADM1026_MANF_REV) {
                if (!probe_only)
                        aprint_verbose("adm1026_ident: "
                            "manufacturer revision invalid or missing\n");
@@ -189,7 +194,7 @@
        else
                div2_val = -1;
 
-       (void) adm1026_ident(sc, 0);
+       (void) adm1026_ident(sc->sc_tag, sc->sc_address, 0, &sc->sc_rev);
        aprint_normal(": ADM1026 hardware monitor: rev. 0x%x, step. 0x%x\n",
            ADM1026_REVISION(sc->sc_rev), ADM1026_STEPPING(sc->sc_rev));
 
@@ -482,18 +487,19 @@
 }
 
 static int
-adm1026_read_reg(struct adm1026_softc *sc, uint8_t reg, uint8_t *val)
+adm1026_read_reg_int(i2c_tag_t tag, i2c_addr_t addr, uint8_t reg,
+    bool multi_read, uint8_t *val)
 {
 #define ADM1026_READ_RETRIES   5
        int i, j, err = 0;
        uint8_t creg, cval, tmp[ADM1026_READ_RETRIES + 1];
 
-       if ((err = iic_acquire_bus(sc->sc_tag, 0)) != 0)
+       if ((err = iic_acquire_bus(tag, 0)) != 0)
                return err;
        /* Standard ADM1026 */
-       if (sc->sc_multi_read == false) {
-               err = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
-                   sc->sc_address, &reg, 1, val, 1, 0);
+       if (multi_read == false) {
+               err = iic_exec(tag, I2C_OP_READ_WITH_STOP,
+                   addr, &reg, 1, val, 1, 0);
        /*
         * The ADM1026 found in some Sun machines sometimes reads bogus values.
         * We'll read at least twice and check that we get (nearly) the same
@@ -505,28 +511,28 @@
                        creg = ADM1026_CONF2;
                else
                        creg = ADM1026_CONF1;
-               if ((err = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
-                   sc->sc_address, &reg, 1, &tmp[0], 1, 0)) != 0) {
-                       iic_release_bus(sc->sc_tag, 0);
+               if ((err = iic_exec(tag, I2C_OP_READ_WITH_STOP,
+                   addr, &reg, 1, &tmp[0], 1, 0)) != 0) {
+                       iic_release_bus(tag, 0);
                        return err;
                }
                for (i = 1; i <= ADM1026_READ_RETRIES; i++) {
-                       if ((err = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
-                           sc->sc_address, &reg, 1, &tmp[i], 1, 0)) != 0)
+                       if ((err = iic_exec(tag, I2C_OP_READ_WITH_STOP,
+                           addr, &reg, 1, &tmp[i], 1, 0)) != 0)
                                break;
                        for (j = 0; j < i; j++)
                                if (abs(tmp[j] - tmp[i]) < 3) {
                                        *val = tmp[i];
-                                       iic_release_bus(sc->sc_tag, 0);
+                                       iic_release_bus(tag, 0);
                                        return 0;
                                }
-                       if ((err = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
-                           sc->sc_address, &creg, 1, &cval, 1, 0)) != 0)
+                       if ((err = iic_exec(tag, I2C_OP_READ_WITH_STOP,
+                           addr, &creg, 1, &cval, 1, 0)) != 0)
                                break;
                        err = -1;       /* Return error if we don't match. */
                }
        }
-       iic_release_bus(sc->sc_tag, 0);
+       iic_release_bus(tag, 0);
        return err;
 }