On 19/08/16 18:32, Thierry Reding wrote:

From: Thierry Reding <redacted>

The Boot and Power Management Processor (BPMP) is a co-processor found
on Tegra SoCs. It is designed to handle the early stages of the boot
process and offload power management tasks (such as clocks, resets,
powergates, ...) as well as system control services.

Compared to the ARM SCPI, the services provided by BPMP are message-
based rather than method-based. The BPMP firmware driver provides the
services to transmit data to and receive data from the BPMP. Users can
also register an MRQ, for which a service routine will be run when a
corresponding event is received from the firmware.

MRQ?

I don't think we want DEBUG by default, right?

+#include <linux/clk/tegra.h>
+#include <linux/mailbox_client.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/semaphore.h>

[snip]

+static int tegra_bpmp_ping(struct tegra_bpmp *bpmp)
+{
+	struct mrq_ping_response response;
+	struct mrq_ping_request request;
+	struct tegra_bpmp_message msg;
+	ktime_t start, delta;
+	unsigned long flags;
+	int err;
+
+	memset(&request, 0, sizeof(request));
+	request.challenge = 1;
+
+	memset(&response, 0, sizeof(response));
+
+	memset(&msg, 0, sizeof(msg));
+	msg.mrq = MRQ_PING;
+	msg.tx.data = &request;
+	msg.tx.size = sizeof(request);
+	msg.rx.data = &response;
+	msg.rx.size = sizeof(response);
+
+	start = ktime_get();
+
+	local_irq_save(flags);
+	err = tegra_bpmp_transfer_atomic(bpmp, &msg);
+	local_irq_restore(flags);
+
+	delta = ktime_sub(ktime_get(), start);
+
+	if (!err)
+		dev_info(bpmp->dev,
+			 "ping ok: challenge: %u, response: %u, time: %lld\n",
+			 request.challenge, response.reply,
+			 ktime_to_us(delta));

Should this be a dev_dbg? I guess this only happens on probe.

+	return err;
+}

[snip]

+static int tegra_bpmp_probe(struct platform_device *pdev)
+{
+	struct tegra_bpmp_channel *channel;
+	struct tegra_bpmp *bpmp;
+	struct device_node *np;
+	struct resource res;
+	unsigned int i;
+	char tag[32];
+	size_t size;
+	int err;
+
+	bpmp = devm_kzalloc(&pdev->dev, sizeof(*bpmp), GFP_KERNEL);
+	if (!bpmp)
+		return -ENOMEM;
+
+	bpmp->soc = of_device_get_match_data(&pdev->dev);
+	bpmp->dev = &pdev->dev;
+
+	np = of_parse_phandle(pdev->dev.of_node, "shmem", 0);
+	if (!np)
+		return -ENOENT;
+
+	of_address_to_resource(np, 0, &res);
+	of_node_put(np);
+
+	bpmp->tx_base = devm_ioremap_resource(&pdev->dev, &res);
+	if (IS_ERR(bpmp->tx_base))
+		return PTR_ERR(bpmp->tx_base);
+
+	np = of_parse_phandle(pdev->dev.of_node, "shmem", 1);
+	if (!np)
+		return -ENOENT;
+
+	of_address_to_resource(np, 0, &res);
+	of_node_put(np);
+
+	bpmp->rx_base = devm_ioremap_resource(&pdev->dev, &res);
+	if (IS_ERR(bpmp->rx_base))
+		return PTR_ERR(bpmp->rx_base);
+
+	bpmp->num_channels = bpmp->soc->channels.cpu_tx.count +
+			     bpmp->soc->channels.thread.count +
+			     bpmp->soc->channels.cpu_rx.count;
+
+	bpmp->channels = devm_kcalloc(&pdev->dev, bpmp->num_channels,
+				      sizeof(*channel), GFP_KERNEL);
+	if (!bpmp->channels)
+		return -ENOMEM;
+
+	/* mbox registration */
+	bpmp->mbox.client.dev = &pdev->dev;
+	bpmp->mbox.client.rx_callback = tegra_bpmp_handle_rx;
+	bpmp->mbox.client.tx_block = false;
+	bpmp->mbox.client.knows_txdone = false;
+
+	bpmp->mbox.channel = mbox_request_channel(&bpmp->mbox.client, 0);
+	if (IS_ERR(bpmp->mbox.channel)) {
+		err = PTR_ERR(bpmp->mbox.channel);
+		dev_err(&pdev->dev, "failed to get HSP mailbox: %d\n", err);
+		return err;
+	}
+
+	/* message channel initialization */
+	for (i = 0; i < bpmp->num_channels; i++) {
+		struct tegra_bpmp_channel *channel = &bpmp->channels[i];
+
+		err = tegra_bpmp_channel_init(channel, bpmp, i);
+		if (err)
+			return err;
+	}

We should make sure we free the mbox if we fail after requesting it.

Cheers
Jon

-- 
nvpublic