hw/gpio: Add GPIO model for Nuvoton NPCM7xx

The NPCM7xx chips have multiple GPIO controllers that are mostly
identical except for some minor differences like the reset values of
some registers. Each controller controls up to 32 pins.

Each individual pin is modeled as a pair of unnamed GPIOs -- one for
emitting the actual pin state, and one for driving the pin externally.
Like the nRF51 GPIO controller, a gpio level may be negative, which
means the pin is not driven, or floating.

Reviewed-by: Tyrone Ting <kfting@nuvoton.com>
Signed-off-by: Havard Skinnemoen <hskinnemoen@google.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

2 files changed, 387 insertions, 1 deletions

diff --git a/tests/qtest/meson.build b/tests/qtest/meson.build
index 43e71a3d5b..c19f1c8503 100644
--- a/tests/qtest/meson.build
+++ b/tests/qtest/meson.build
@@ -134,7 +134,8 @@ qtests_sparc64 = \
   ['prom-env-test', 'boot-serial-test']
 
 qtests_npcm7xx = \
-  ['npcm7xx_rng-test',
+  ['npcm7xx_gpio-test',
+   'npcm7xx_rng-test',
    'npcm7xx_timer-test',
    'npcm7xx_watchdog_timer-test']
 qtests_arm = \
diff --git a/tests/qtest/npcm7xx_gpio-test.c b/tests/qtest/npcm7xx_gpio-test.c
new file mode 100644
index 0000000000..1004cef812
--- /dev/null
+++ b/tests/qtest/npcm7xx_gpio-test.c
@@ -0,0 +1,385 @@
+/*
+ * QTest testcase for the Nuvoton NPCM7xx GPIO modules.
+ *
+ * Copyright 2020 Google LLC
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ */
+
+#include "qemu/osdep.h"
+#include "libqtest-single.h"
+
+#define NR_GPIO_DEVICES (8)
+#define GPIO(x)         (0xf0010000 + (x) * 0x1000)
+#define GPIO_IRQ(x)     (116 + (x))
+
+/* GPIO registers */
+#define GP_N_TLOCK1     0x00
+#define GP_N_DIN        0x04 /* Data IN */
+#define GP_N_POL        0x08 /* Polarity */
+#define GP_N_DOUT       0x0c /* Data OUT */
+#define GP_N_OE         0x10 /* Output Enable */
+#define GP_N_OTYP       0x14
+#define GP_N_MP         0x18
+#define GP_N_PU         0x1c /* Pull-up */
+#define GP_N_PD         0x20 /* Pull-down */
+#define GP_N_DBNC       0x24 /* Debounce */
+#define GP_N_EVTYP      0x28 /* Event Type */
+#define GP_N_EVBE       0x2c /* Event Both Edge */
+#define GP_N_OBL0       0x30
+#define GP_N_OBL1       0x34
+#define GP_N_OBL2       0x38
+#define GP_N_OBL3       0x3c
+#define GP_N_EVEN       0x40 /* Event Enable */
+#define GP_N_EVENS      0x44 /* Event Set (enable) */
+#define GP_N_EVENC      0x48 /* Event Clear (disable) */
+#define GP_N_EVST       0x4c /* Event Status */
+#define GP_N_SPLCK      0x50
+#define GP_N_MPLCK      0x54
+#define GP_N_IEM        0x58 /* Input Enable */
+#define GP_N_OSRC       0x5c
+#define GP_N_ODSC       0x60
+#define GP_N_DOS        0x68 /* Data OUT Set */
+#define GP_N_DOC        0x6c /* Data OUT Clear */
+#define GP_N_OES        0x70 /* Output Enable Set */
+#define GP_N_OEC        0x74 /* Output Enable Clear */
+#define GP_N_TLOCK2     0x7c
+
+static void gpio_unlock(int n)
+{
+    if (readl(GPIO(n) + GP_N_TLOCK1) != 0) {
+        writel(GPIO(n) + GP_N_TLOCK2, 0xc0de1248);
+        writel(GPIO(n) + GP_N_TLOCK1, 0xc0defa73);
+    }
+}
+
+/* Restore the GPIO controller to a sensible default state. */
+static void gpio_reset(int n)
+{
+    gpio_unlock(0);
+
+    writel(GPIO(n) + GP_N_EVEN, 0x00000000);
+    writel(GPIO(n) + GP_N_EVST, 0xffffffff);
+    writel(GPIO(n) + GP_N_POL, 0x00000000);
+    writel(GPIO(n) + GP_N_DOUT, 0x00000000);
+    writel(GPIO(n) + GP_N_OE, 0x00000000);
+    writel(GPIO(n) + GP_N_OTYP, 0x00000000);
+    writel(GPIO(n) + GP_N_PU, 0xffffffff);
+    writel(GPIO(n) + GP_N_PD, 0x00000000);
+    writel(GPIO(n) + GP_N_IEM, 0xffffffff);
+}
+
+static void test_dout_to_din(void)
+{
+    gpio_reset(0);
+
+    /* When output is enabled, DOUT should be reflected on DIN. */
+    writel(GPIO(0) + GP_N_OE, 0xffffffff);
+    /* PU and PD shouldn't have any impact on DIN. */
+    writel(GPIO(0) + GP_N_PU, 0xffff0000);
+    writel(GPIO(0) + GP_N_PD, 0x0000ffff);
+    writel(GPIO(0) + GP_N_DOUT, 0x12345678);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_DOUT), ==, 0x12345678);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_DIN), ==, 0x12345678);
+}
+
+static void test_pullup_pulldown(void)
+{
+    gpio_reset(0);
+
+    /*
+     * When output is disabled, and PD is the inverse of PU, PU should be
+     * reflected on DIN. If PD is not the inverse of PU, the state of DIN is
+     * undefined, so we don't test that.
+     */
+    writel(GPIO(0) + GP_N_OE, 0x00000000);
+    /* DOUT shouldn't have any impact on DIN. */
+    writel(GPIO(0) + GP_N_DOUT, 0xffff0000);
+    writel(GPIO(0) + GP_N_PU, 0x23456789);
+    writel(GPIO(0) + GP_N_PD, ~0x23456789U);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_PU), ==, 0x23456789);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_PD), ==, ~0x23456789U);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_DIN), ==, 0x23456789);
+}
+
+static void test_output_enable(void)
+{
+    gpio_reset(0);
+
+    /*
+     * With all pins weakly pulled down, and DOUT all-ones, OE should be
+     * reflected on DIN.
+     */
+    writel(GPIO(0) + GP_N_DOUT, 0xffffffff);
+    writel(GPIO(0) + GP_N_PU, 0x00000000);
+    writel(GPIO(0) + GP_N_PD, 0xffffffff);
+    writel(GPIO(0) + GP_N_OE, 0x3456789a);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_OE), ==, 0x3456789a);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_DIN), ==, 0x3456789a);
+
+    writel(GPIO(0) + GP_N_OEC, 0x00030002);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_OE), ==, 0x34547898);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_DIN), ==, 0x34547898);
+
+    writel(GPIO(0) + GP_N_OES, 0x0000f001);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_OE), ==, 0x3454f899);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_DIN), ==, 0x3454f899);
+}
+
+static void test_open_drain(void)
+{
+    gpio_reset(0);
+
+    /*
+     * Upper half of DOUT drives a 1 only if the corresponding bit in OTYP is
+     * not set. If OTYP is set, DIN is determined by PU/PD. Lower half of
+     * DOUT always drives a 0 regardless of OTYP; PU/PD have no effect.  When
+     * OE is 0, output is determined by PU/PD; OTYP has no effect.
+     */
+    writel(GPIO(0) + GP_N_OTYP, 0x456789ab);
+    writel(GPIO(0) + GP_N_OE, 0xf0f0f0f0);
+    writel(GPIO(0) + GP_N_DOUT, 0xffff0000);
+    writel(GPIO(0) + GP_N_PU, 0xff00ff00);
+    writel(GPIO(0) + GP_N_PD, 0x00ff00ff);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_OTYP), ==, 0x456789ab);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_DIN), ==, 0xff900f00);
+}
+
+static void test_polarity(void)
+{
+    gpio_reset(0);
+
+    /*
+     * In push-pull mode, DIN should reflect DOUT because the signal is
+     * inverted in both directions.
+     */
+    writel(GPIO(0) + GP_N_OTYP, 0x00000000);
+    writel(GPIO(0) + GP_N_OE, 0xffffffff);
+    writel(GPIO(0) + GP_N_DOUT, 0x56789abc);
+    writel(GPIO(0) + GP_N_POL, 0x6789abcd);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_POL), ==, 0x6789abcd);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_DIN), ==, 0x56789abc);
+
+    /*
+     * When turning off the drivers, DIN should reflect the inverse of the
+     * pulled-up lines.
+     */
+    writel(GPIO(0) + GP_N_OE, 0x00000000);
+    writel(GPIO(0) + GP_N_POL, 0xffffffff);
+    writel(GPIO(0) + GP_N_PU, 0x789abcde);
+    writel(GPIO(0) + GP_N_PD, ~0x789abcdeU);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_DIN), ==, ~0x789abcdeU);
+
+    /*
+     * In open-drain mode, DOUT=1 will appear to drive the pin high (since DIN
+     * is inverted), while DOUT=0 will leave the pin floating.
+     */
+    writel(GPIO(0) + GP_N_OTYP, 0xffffffff);
+    writel(GPIO(0) + GP_N_OE, 0xffffffff);
+    writel(GPIO(0) + GP_N_PU, 0xffff0000);
+    writel(GPIO(0) + GP_N_PD, 0x0000ffff);
+    writel(GPIO(0) + GP_N_DOUT, 0xff00ff00);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_DIN), ==, 0xff00ffff);
+}
+
+static void test_input_mask(void)
+{
+    gpio_reset(0);
+
+    /* IEM=0 forces the input to zero before polarity inversion. */
+    writel(GPIO(0) + GP_N_OE, 0xffffffff);
+    writel(GPIO(0) + GP_N_DOUT, 0xff00ff00);
+    writel(GPIO(0) + GP_N_POL, 0xffff0000);
+    writel(GPIO(0) + GP_N_IEM, 0x87654321);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_DIN), ==, 0xff9a4300);
+}
+
+static void test_temp_lock(void)
+{
+    gpio_reset(0);
+
+    writel(GPIO(0) + GP_N_DOUT, 0x98765432);
+
+    /* Make sure we're unlocked initially. */
+    g_assert_cmphex(readl(GPIO(0) + GP_N_TLOCK1), ==, 0);
+    /* Writing any value to TLOCK1 will lock. */
+    writel(GPIO(0) + GP_N_TLOCK1, 0);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_TLOCK1), ==, 1);
+    writel(GPIO(0) + GP_N_DOUT, 0xa9876543);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_DOUT), ==, 0x98765432);
+    /* Now, try to unlock. */
+    gpio_unlock(0);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_TLOCK1), ==, 0);
+    writel(GPIO(0) + GP_N_DOUT, 0xa9876543);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_DOUT), ==, 0xa9876543);
+
+    /* Try it again, but write TLOCK2 to lock. */
+    writel(GPIO(0) + GP_N_TLOCK2, 0);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_TLOCK1), ==, 1);
+    writel(GPIO(0) + GP_N_DOUT, 0x98765432);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_DOUT), ==, 0xa9876543);
+    /* Now, try to unlock. */
+    gpio_unlock(0);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_TLOCK1), ==, 0);
+    writel(GPIO(0) + GP_N_DOUT, 0x98765432);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_DOUT), ==, 0x98765432);
+}
+
+static void test_events_level(void)
+{
+    gpio_reset(0);
+
+    writel(GPIO(0) + GP_N_EVTYP, 0x00000000);
+    writel(GPIO(0) + GP_N_DOUT, 0xba987654);
+    writel(GPIO(0) + GP_N_OE, 0xffffffff);
+    writel(GPIO(0) + GP_N_EVST, 0xffffffff);
+
+    g_assert_cmphex(readl(GPIO(0) + GP_N_EVST), ==, 0xba987654);
+    g_assert_false(qtest_get_irq(global_qtest, GPIO_IRQ(0)));
+    writel(GPIO(0) + GP_N_DOUT, 0x00000000);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_EVST), ==, 0xba987654);
+    g_assert_false(qtest_get_irq(global_qtest, GPIO_IRQ(0)));
+    writel(GPIO(0) + GP_N_EVST, 0x00007654);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_EVST), ==, 0xba980000);
+    g_assert_false(qtest_get_irq(global_qtest, GPIO_IRQ(0)));
+    writel(GPIO(0) + GP_N_EVST, 0xba980000);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_EVST), ==, 0x00000000);
+    g_assert_false(qtest_get_irq(global_qtest, GPIO_IRQ(0)));
+}
+
+static void test_events_rising_edge(void)
+{
+    gpio_reset(0);
+
+    writel(GPIO(0) + GP_N_EVTYP, 0xffffffff);
+    writel(GPIO(0) + GP_N_EVBE, 0x00000000);
+    writel(GPIO(0) + GP_N_DOUT, 0xffff0000);
+    writel(GPIO(0) + GP_N_OE, 0xffffffff);
+    writel(GPIO(0) + GP_N_EVST, 0xffffffff);
+
+    g_assert_cmphex(readl(GPIO(0) + GP_N_EVST), ==, 0x00000000);
+    g_assert_false(qtest_get_irq(global_qtest, GPIO_IRQ(0)));
+    writel(GPIO(0) + GP_N_DOUT, 0xff00ff00);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_EVST), ==, 0x0000ff00);
+    g_assert_false(qtest_get_irq(global_qtest, GPIO_IRQ(0)));
+    writel(GPIO(0) + GP_N_DOUT, 0x00ff0000);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_EVST), ==, 0x00ffff00);
+    g_assert_false(qtest_get_irq(global_qtest, GPIO_IRQ(0)));
+    writel(GPIO(0) + GP_N_EVST, 0x0000f000);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_EVST), ==, 0x00ff0f00);
+    g_assert_false(qtest_get_irq(global_qtest, GPIO_IRQ(0)));
+    writel(GPIO(0) + GP_N_EVST, 0x00ff0f00);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_EVST), ==, 0x00000000);
+    g_assert_false(qtest_get_irq(global_qtest, GPIO_IRQ(0)));
+}
+
+static void test_events_both_edges(void)
+{
+    gpio_reset(0);
+
+    writel(GPIO(0) + GP_N_EVTYP, 0xffffffff);
+    writel(GPIO(0) + GP_N_EVBE, 0xffffffff);
+    writel(GPIO(0) + GP_N_DOUT, 0xffff0000);
+    writel(GPIO(0) + GP_N_OE, 0xffffffff);
+    writel(GPIO(0) + GP_N_EVST, 0xffffffff);
+
+    g_assert_cmphex(readl(GPIO(0) + GP_N_EVST), ==, 0x00000000);
+    g_assert_false(qtest_get_irq(global_qtest, GPIO_IRQ(0)));
+    writel(GPIO(0) + GP_N_DOUT, 0xff00ff00);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_EVST), ==, 0x00ffff00);
+    g_assert_false(qtest_get_irq(global_qtest, GPIO_IRQ(0)));
+    writel(GPIO(0) + GP_N_DOUT, 0xef00ff08);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_EVST), ==, 0x10ffff08);
+    g_assert_false(qtest_get_irq(global_qtest, GPIO_IRQ(0)));
+    writel(GPIO(0) + GP_N_EVST, 0x0000f000);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_EVST), ==, 0x10ff0f08);
+    g_assert_false(qtest_get_irq(global_qtest, GPIO_IRQ(0)));
+    writel(GPIO(0) + GP_N_EVST, 0x10ff0f08);
+    g_assert_cmphex(readl(GPIO(0) + GP_N_EVST), ==, 0x00000000);
+    g_assert_false(qtest_get_irq(global_qtest, GPIO_IRQ(0)));
+}
+
+static void test_gpion_irq(gconstpointer test_data)
+{
+    intptr_t n = (intptr_t)test_data;
+
+    gpio_reset(n);
+
+    writel(GPIO(n) + GP_N_EVTYP, 0x00000000);
+    writel(GPIO(n) + GP_N_DOUT, 0x00000000);
+    writel(GPIO(n) + GP_N_OE, 0xffffffff);
+    writel(GPIO(n) + GP_N_EVST, 0xffffffff);
+    writel(GPIO(n) + GP_N_EVEN, 0x00000000);
+
+    /* Trigger an event; interrupts are masked. */
+    g_assert_cmphex(readl(GPIO(n) + GP_N_EVST), ==, 0x00000000);
+    g_assert_false(qtest_get_irq(global_qtest, GPIO_IRQ(n)));
+    writel(GPIO(n) + GP_N_DOS, 0x00008000);
+    g_assert_cmphex(readl(GPIO(n) + GP_N_EVST), ==, 0x00008000);
+    g_assert_false(qtest_get_irq(global_qtest, GPIO_IRQ(n)));
+
+    /* Unmask all event interrupts; verify that the interrupt fired. */
+    writel(GPIO(n) + GP_N_EVEN, 0xffffffff);
+    g_assert_true(qtest_get_irq(global_qtest, GPIO_IRQ(n)));
+
+    /* Clear the current bit, set a new bit, irq stays asserted. */
+    writel(GPIO(n) + GP_N_DOC, 0x00008000);
+    g_assert_true(qtest_get_irq(global_qtest, GPIO_IRQ(n)));
+    writel(GPIO(n) + GP_N_DOS, 0x00000200);
+    g_assert_true(qtest_get_irq(global_qtest, GPIO_IRQ(n)));
+    writel(GPIO(n) + GP_N_EVST, 0x00008000);
+    g_assert_true(qtest_get_irq(global_qtest, GPIO_IRQ(n)));
+
+    /* Mask/unmask the event that's currently active. */
+    writel(GPIO(n) + GP_N_EVENC, 0x00000200);
+    g_assert_false(qtest_get_irq(global_qtest, GPIO_IRQ(n)));
+    writel(GPIO(n) + GP_N_EVENS, 0x00000200);
+    g_assert_true(qtest_get_irq(global_qtest, GPIO_IRQ(n)));
+
+    /* Clear the input and the status bit, irq is deasserted. */
+    writel(GPIO(n) + GP_N_DOC, 0x00000200);
+    g_assert_true(qtest_get_irq(global_qtest, GPIO_IRQ(n)));
+    writel(GPIO(n) + GP_N_EVST, 0x00000200);
+    g_assert_false(qtest_get_irq(global_qtest, GPIO_IRQ(n)));
+}
+
+int main(int argc, char **argv)
+{
+    int ret;
+    int i;
+
+    g_test_init(&argc, &argv, NULL);
+    g_test_set_nonfatal_assertions();
+
+    qtest_add_func("/npcm7xx_gpio/dout_to_din", test_dout_to_din);
+    qtest_add_func("/npcm7xx_gpio/pullup_pulldown", test_pullup_pulldown);
+    qtest_add_func("/npcm7xx_gpio/output_enable", test_output_enable);
+    qtest_add_func("/npcm7xx_gpio/open_drain", test_open_drain);
+    qtest_add_func("/npcm7xx_gpio/polarity", test_polarity);
+    qtest_add_func("/npcm7xx_gpio/input_mask", test_input_mask);
+    qtest_add_func("/npcm7xx_gpio/temp_lock", test_temp_lock);
+    qtest_add_func("/npcm7xx_gpio/events/level", test_events_level);
+    qtest_add_func("/npcm7xx_gpio/events/rising_edge", test_events_rising_edge);
+    qtest_add_func("/npcm7xx_gpio/events/both_edges", test_events_both_edges);
+
+    for (i = 0; i < NR_GPIO_DEVICES; i++) {
+        g_autofree char *test_name =
+            g_strdup_printf("/npcm7xx_gpio/gpio[%d]/irq", i);
+        qtest_add_data_func(test_name, (void *)(intptr_t)i, test_gpion_irq);
+    }
+
+    qtest_start("-machine npcm750-evb");
+    qtest_irq_intercept_in(global_qtest, "/machine/soc/a9mpcore/gic");
+    ret = g_test_run();
+    qtest_end();
+
+    return ret;
+}