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Message-ID: <6f95d492-2f5e-42e8-acdd-210d6a03b14c@kernel.org>
Date: Thu, 14 Sep 2023 09:16:04 +0200
From: Jiri Slaby <jirislaby@...nel.org>
To: Max Filippov <jcmvbkbc@...il.com>, linux-kernel@...r.kernel.org,
linux-serial@...r.kernel.org, devicetree@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Rob Herring <robh+dt@...nel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
Conor Dooley <conor+dt@...nel.org>
Subject: Re: [PATCH 4/4] drivers/tty/serial: add ESP32S3 ACM device driver
On 13. 09. 23, 23:14, Max Filippov wrote:
> Add driver for the ACM controller of the Espressif ESP32S3 Soc.
> Hardware specification is available at the following URL:
>
> https://www.espressif.com/sites/default/files/documentation/esp32-s3_technical_reference_manual_en.pdf
> (Chapter 33 USB Serial/JTAG Controller)
...
> +static void esp32s3_acm_put_char_sync(struct uart_port *port, unsigned char c)
> +{
> + while (!esp32s3_acm_tx_fifo_free(port))
> + cpu_relax();
No limits...
> + esp32s3_acm_put_char(port, c);
> + esp32s3_acm_push(port);
> +}
> +
> +static void esp32s3_acm_transmit_buffer(struct uart_port *port)
> +{
tx helper.
> + struct circ_buf *xmit = &port->state->xmit;
> + u32 tx_fifo_used = esp32s3_acm_tx_fifo_cnt(port);
> +
> + if (esp32s3_acm_tx_fifo_free(port)) {
> + while (!uart_circ_empty(xmit) && tx_fifo_used < ESP32S3_ACM_TX_FIFO_SIZE) {
> + esp32s3_acm_put_char(port, xmit->buf[xmit->tail]);
> + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
> + port->icount.tx++;
> + ++tx_fifo_used;
> + }
> + }
> +
> + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
> + uart_write_wakeup(port);
> +
> + if (uart_circ_empty(xmit)) {
> + esp32s3_acm_stop_tx(port);
> + } else {
> + u32 int_ena;
> +
> + int_ena = esp32s3_acm_read(port, USB_SERIAL_JTAG_INT_ENA_REG);
> + esp32s3_acm_write(port, USB_SERIAL_JTAG_INT_ENA_REG,
> + int_ena | USB_SERIAL_JTAG_SERIAL_IN_EMPTY_INT_ENA_MASK);
> + }
> +
> + if (tx_fifo_used > 0 && tx_fifo_used < ESP32S3_ACM_TX_FIFO_SIZE)
> + esp32s3_acm_write(port, USB_SERIAL_JTAG_EP1_CONF_REG,
> + USB_SERIAL_JTAG_WR_DONE_MASK);
> +}
> +static irqreturn_t esp32s3_acm_int(int irq, void *dev_id)
> +{
> + struct uart_port *port = dev_id;
> + u32 status;
> +
> + status = esp32s3_acm_read(port, USB_SERIAL_JTAG_INT_ST_REG);
> + esp32s3_acm_write(port, USB_SERIAL_JTAG_INT_CLR_REG, status);
> +
> + if (status & USB_SERIAL_JTAG_SERIAL_OUT_RECV_PKT_INT_ST_MASK)
> + esp32s3_acm_rxint(port);
> + if (status & USB_SERIAL_JTAG_SERIAL_IN_EMPTY_INT_ST_MASK)
> + esp32s3_acm_txint(port);
> +
> + return IRQ_HANDLED;
IRQ_STATUS()
> +}
> +static int esp32s3_acm_startup(struct uart_port *port)
> +{
> + int ret = 0;
> +
> + esp32s3_acm_write(port, USB_SERIAL_JTAG_INT_ENA_REG,
> + USB_SERIAL_JTAG_SERIAL_OUT_RECV_PKT_INT_ENA_MASK);
> + ret = devm_request_irq(port->dev, port->irq, esp32s3_acm_int, 0,
> + DRIVER_NAME, port);
> + return ret;
No need for ret. Or not, you don't handle the failure properly again
(disable ints). And the order appears to be switched too.
> +static void
> +esp32s3_acm_console_write(struct console *co, const char *s, unsigned int count)
> +{
> + struct uart_port *port = esp32s3_acm_ports[co->index];
> + unsigned long flags;
> + int locked = 1;
bool? ANd in the otrher driver too.
> +
> + if (port->sysrq)
> + locked = 0;
> + else if (oops_in_progress)
> + locked = spin_trylock_irqsave(&port->lock, flags);
> + else
> + spin_lock_irqsave(&port->lock, flags);
> +
> + esp32s3_acm_string_write(port, s, count);
> +
> + if (locked)
> + spin_unlock_irqrestore(&port->lock, flags);
> +}
> +#ifdef CONFIG_CONSOLE_POLL
> +static int esp32s3_acm_earlycon_read(struct console *con, char *s, unsigned int n)
> +{
> + struct earlycon_device *dev = con->data;
> + int num_read = 0;
num looks like should be unsigned?
> +
> + while (num_read < n) {
> + int c = esp32s3_acm_poll_get_char(&dev->port);
> +
> + if (c == NO_POLL_CHAR)
> + break;
> + s[num_read++] = c;
> + }
> + return num_read;
> +}
> +#endif
> +static int esp32s3_acm_probe(struct platform_device *pdev)
> +{
> + struct device_node *np = pdev->dev.of_node;
> + struct uart_port *port;
> + struct resource *res;
> + int ret;
> +
> + port = devm_kzalloc(&pdev->dev, sizeof(*port), GFP_KERNEL);
> + if (!port)
> + return -ENOMEM;
> +
> + ret = of_alias_get_id(np, "serial");
> + if (ret < 0) {
> + dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
> + return ret;
> + }
> + if (ret >= UART_NR) {
> + dev_err(&pdev->dev, "driver limited to %d serial ports\n",
> + UART_NR);
> + return -ENOMEM;
> + }
> +
> + port->line = ret;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res)
> + return -ENODEV;
> +
> + port->mapbase = res->start;
> + port->membase = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(port->membase))
> + return PTR_ERR(port->membase);
> +
> + port->dev = &pdev->dev;
> + port->type = PORT_ESP32ACM;
> + port->iotype = UPIO_MEM;
> + port->irq = platform_get_irq(pdev, 0);
> + port->ops = &esp32s3_acm_pops;
> + port->flags = UPF_BOOT_AUTOCONF;
> + port->has_sysrq = 1;
> + port->fifosize = ESP32S3_ACM_TX_FIFO_SIZE;
> +
> + esp32s3_acm_ports[port->line] = port;
> +
> + platform_set_drvdata(pdev, port);
> +
> + ret = uart_add_one_port(&esp32s3_acm_reg, port);
> + return ret;
return imm.
> +}
regards,
--
js
suse labs
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