[src/trunk]: src/sys/arch/arm/rockchip - implement sub-5degC interpolation.

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

details:   https://anonhg.NetBSD.org/src/rev/3dd96526eddc
branches:  trunk
changeset: 456177:3dd96526eddc
user:      mrg <mrg%NetBSD.org@localhost>
date:      Fri Apr 26 10:20:09 2019 +0000

description:
- implement sub-5degC interpolation.
- avoid setting TSADC_AUTO_CON_SRC*_EN twice

diffstat:

 sys/arch/arm/rockchip/rk_tsadc.c |  54 +++++++++++++++++++++++++++------------
 1 files changed, 37 insertions(+), 17 deletions(-)

diffs (138 lines):

diff -r c94a1005dfdd -r 3dd96526eddc sys/arch/arm/rockchip/rk_tsadc.c
--- a/sys/arch/arm/rockchip/rk_tsadc.c  Fri Apr 26 10:11:14 2019 +0000
+++ b/sys/arch/arm/rockchip/rk_tsadc.c  Fri Apr 26 10:20:09 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rk_tsadc.c,v 1.1 2019/04/26 08:28:11 mrg Exp $ */
+/*     $NetBSD: rk_tsadc.c,v 1.2 2019/04/26 10:20:09 mrg Exp $ */
 
 /*
  * Copyright (c) 2019 Matthew R. Green
@@ -30,14 +30,13 @@
 
 #include <sys/cdefs.h>
 
-__KERNEL_RCSID(0, "$NetBSD: rk_tsadc.c,v 1.1 2019/04/26 08:28:11 mrg Exp $");
+__KERNEL_RCSID(0, "$NetBSD: rk_tsadc.c,v 1.2 2019/04/26 10:20:09 mrg Exp $");
 
 /*
  * Driver for the TSADC temperature sensor monitor in RK3328 and RK3399.
  *
  * TODO:
  * - handle setting various temp values
- * - add interpolation between the 5degC intervals in sample data
  * - handle DT trips/temp value defaults
  * - interrupts aren't triggered (test by lowering warn/crit values), and
  *   once they work, make the interrupt do something
@@ -202,6 +201,7 @@
        ENTRY(668, 115),
        ENTRY(677, 120),
        ENTRY(685, 125),
+       ENTRY(TSADC_DATA_MAX, 125),
 #undef ENTRY
 };
 
@@ -213,6 +213,7 @@
        unsigned        s_data_reg;
        unsigned        s_comp_tshut;
        unsigned        s_comp_int;
+       /* enable bit in AUTO_CON register */
        unsigned        s_comp_int_en;
        /* warn/crit values in micro Kelvin */
        int             s_warn;
@@ -335,7 +336,7 @@
        sc->sc_sme->sme_cookie = sc;
        sc->sc_sme->sme_refresh = rk_tsadc_refresh;
        sc->sc_sme->sme_get_limits = rk_tsadc_get_limits;
-       sc->sc_data_mask = 0xfff;
+       sc->sc_data_mask = TSADC_DATA_MAX;
 
        pmf_device_register(self, NULL, NULL);
 
@@ -375,10 +376,10 @@
                        goto fail;
                rks->s_attached = true;
                rks->s_tshut = tshut_temp;
-#if 0
+#if 1
                // testing
-               rks->s_tshut = 65000000;
-               rks->s_warn = 60000000;
+               rks->s_tshut = 68000000;
+               rks->s_warn = 61000000;
 #endif
        }
 
@@ -605,8 +606,7 @@
 
        val = TSADC_READ(sc, TSADC_AUTO_CON);
        val |= TSADC_AUTO_CON_AUTO_STATUS | 
-              TSADC_AUTO_CON_SRC1_LT_EN | TSADC_AUTO_CON_SRC0_LT_EN |
-              TSADC_AUTO_CON_SRC1_EN | TSADC_AUTO_CON_SRC0_EN;
+              TSADC_AUTO_CON_SRC1_LT_EN | TSADC_AUTO_CON_SRC0_LT_EN;
        TSADC_WRITE(sc, TSADC_AUTO_CON, val);
 
        /* Finally, register & enable the controller */
@@ -698,24 +698,33 @@
  * and temperature values in 5 degC intervals, but says that interpolation
  * can be done to achieve better resolution between these values, and that
  * the spacing is linear.
- *
- * XXX The sub-entry interpolation is not yet done.
  */
 static int
 rk_tsadc_data_to_temp(struct rk_tsadc_softc *sc, uint32_t data)
 {
        unsigned i;
 
-       for (i = 1; i < __arraycount(rk3399_data_table); i++) {
+       for (i = 1; i < __arraycount(rk3399_data_table) - 1; i++) {
                if (rk3399_data_table[i].data >= data) {
+                       int temprange, offset;
+                       uint32_t datarange, datadiff;
+
                        if (rk3399_data_table[i].data == data)
                                return rk3399_data_table[i].temp;
-                       /* XXX interpolate */
-                       return rk3399_data_table[i-1].temp;
+
+                       /* must interpolate */
+                       temprange = rk3399_data_table[i].temp -
+                                   rk3399_data_table[i-1].temp;
+                       datarange = rk3399_data_table[i].data -
+                                   rk3399_data_table[i-1].data;
+                       datadiff = data - rk3399_data_table[i-1].data;
+
+                       offset = (temprange * datadiff) / datarange;
+                       return rk3399_data_table[i-1].temp + offset;
                }
        }
 
-       return rk3399_data_table[i-1].temp;
+       return rk3399_data_table[i].temp;
 }
 
 static uint32_t
@@ -725,10 +734,21 @@
 
        for (i = 1; i < __arraycount(rk3399_data_table); i++) {
                if (rk3399_data_table[i].temp >= temp) {
+                       int temprange, tempdiff;
+                       uint32_t datarange, offset;
+
                        if (rk3399_data_table[i].temp == temp)
                                return rk3399_data_table[i].data;
-                       /* XXX interpolate */
-                       return rk3399_data_table[i-1].data;
+
+                       /* must interpolate */
+                       datarange = rk3399_data_table[i].data -
+                                   rk3399_data_table[i-1].data;
+                       temprange = rk3399_data_table[i].temp -
+                                   rk3399_data_table[i-1].temp;
+                       tempdiff = temp - rk3399_data_table[i-1].temp;
+
+                       offset = (datarange * tempdiff) / temprange;
+                       return rk3399_data_table[i-1].data + offset;
                }
        }