Add qccpucp(4), a driver for the CPUSS Control Processor (CPUCP) mailbox

controller. It is used as doorbell for the arm-scmi perf protocol and
a prerequisite for cpu frequency management on X Elite chips.

ok patrick@

1 files changed, 166 insertions, 0 deletions

diff --git a/sys/dev/fdt/qccpucp.c b/sys/dev/fdt/qccpucp.c
new file mode 100644
index 00000000000..bb0e78ddcd4
--- /dev/null
+++ b/sys/dev/fdt/qccpucp.c
@@ -0,0 +1,166 @@
+/*	$OpenBSD: qccpucp.c,v 1.1 2024/11/16 21:17:54 tobhe Exp $	*/
+/*
+ * Copyright (c) 2024 Tobias Heider <tobhe@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/device.h>
+#include <sys/malloc.h>
+
+#include <machine/bus.h>
+#include <machine/fdt.h>
+
+#include <dev/ofw/openfirm.h>
+#include <dev/ofw/ofw_misc.h>
+#include <dev/ofw/fdt.h>
+
+#define CPUCP_MAX_CHANNELS	3
+
+/* Registers */
+#define CPUCP_REG_CMD(i)	(0x104 + ((i) * 8))
+#define CPUCP_MASK_CMD		0xffffffffffffffffULL
+#define CPUCP_REG_RX_MAP	0x4000
+#define CPUCP_REG_RX_STAT	0x4400
+#define CPUCP_REG_RX_CLEAR	0x4800
+#define CPUCP_REG_RX_EN		0x4C00
+
+#define RXREAD8(sc, reg)						\
+	(bus_space_read_8((sc)->sc_iot, (sc)->sc_rx_ioh, (reg)))
+#define RXWRITE8(sc, reg, val)						\
+	bus_space_write_8((sc)->sc_iot, (sc)->sc_rx_ioh, (reg), (val))
+
+#define TXWRITE4(sc, reg, val)						\
+	bus_space_write_4((sc)->sc_iot, (sc)->sc_tx_ioh, (reg), (val))
+
+struct qccpucp_channel {
+	struct qccpucp_softc	*ch_sc;
+
+	int			 ch_idx;
+};
+
+struct qccpucp_softc {
+	struct device		sc_dev;
+	bus_space_tag_t		sc_iot;
+	bus_space_handle_t	sc_rx_ioh;
+	bus_space_handle_t	sc_tx_ioh;
+
+	void			*sc_ih;
+
+	struct qccpucp_channel	sc_chans[CPUCP_MAX_CHANNELS];
+
+	struct mbox_device	sc_md;
+};
+
+int	qccpucp_match(struct device *, void *, void *);
+void	qccpucp_attach(struct device *, struct device *, void *);
+
+const struct cfattach qccpucp_ca = {
+	sizeof (struct qccpucp_softc), qccpucp_match, qccpucp_attach
+};
+
+struct cfdriver qccpucp_cd = {
+	NULL, "qccpucp", DV_DULL
+};
+
+void	*qccpucp_channel(void *, uint32_t *, struct mbox_client *);
+int	qccpucp_send(void *, const void *, size_t);
+
+int
+qccpucp_match(struct device *parent, void *match, void *aux)
+{
+	struct fdt_attach_args *faa = aux;
+
+	return OF_is_compatible(faa->fa_node, "qcom,x1e80100-cpucp-mbox");
+}
+
+void
+qccpucp_attach(struct device *parent, struct device *self, void *aux)
+{
+	struct qccpucp_softc *sc = (struct qccpucp_softc *)self;
+	struct fdt_attach_args *faa = aux;
+
+	if (faa->fa_nreg < 2) {
+		printf(": no registers\n");
+		return;
+	}
+
+	sc->sc_iot = faa->fa_iot;
+	if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr,
+	    faa->fa_reg[0].size, 0, &sc->sc_rx_ioh)) {
+		printf(": can't map registers\n");
+		return;
+	}
+	if (bus_space_map(sc->sc_iot, faa->fa_reg[1].addr,
+	    faa->fa_reg[1].size, 0, &sc->sc_tx_ioh)) {
+		printf(": can't map registers\n");
+		bus_space_unmap(sc->sc_iot, sc->sc_rx_ioh,
+		    faa->fa_reg[0].size);
+		return;
+	}
+
+	RXWRITE8(sc, CPUCP_REG_RX_EN, 0);
+	RXWRITE8(sc, CPUCP_REG_RX_CLEAR, 0);
+	RXWRITE8(sc, CPUCP_REG_RX_MAP, 0);
+
+	printf("\n");
+
+	RXWRITE8(sc, CPUCP_REG_RX_MAP, CPUCP_MASK_CMD);
+
+	sc->sc_md.md_node = faa->fa_node;
+	sc->sc_md.md_cookie = sc;
+	sc->sc_md.md_channel = qccpucp_channel;
+	sc->sc_md.md_send = qccpucp_send;
+	mbox_register(&sc->sc_md);
+}
+
+void *
+qccpucp_channel(void *cookie, uint32_t *cells, struct mbox_client *mc)
+{
+	struct qccpucp_softc *sc = cookie;
+	struct qccpucp_channel *ch = NULL;
+	uint64_t val;
+	int i;
+
+	for (i = 0; i < CPUCP_MAX_CHANNELS; i++) {
+		if (sc->sc_chans[i].ch_sc == NULL) {
+			ch = &sc->sc_chans[i];
+			break;
+		}
+	}
+
+	if (ch == NULL)
+		return NULL;
+
+	val = RXREAD8(sc, CPUCP_REG_RX_EN);
+	val |= (1 << i);
+	RXWRITE8(sc, CPUCP_REG_RX_EN, val);
+	
+	ch->ch_idx = i;
+	ch->ch_sc = sc;
+
+	return ch;
+}
+
+int
+qccpucp_send(void *cookie, const void *data, size_t len)
+{
+	struct qccpucp_channel *ch = cookie;
+	struct qccpucp_softc *sc = ch->ch_sc;
+
+	TXWRITE4(sc, CPUCP_REG_CMD(ch->ch_idx), 0);
+	
+	return 0;
+}