Re: [PATCH v7 2/2] tty/serial: Add Spreadtrum sc9836-uart driver support

On Fri, Jan 23, 2015 at 9:31 PM, Peter Hurley [off-list ref] wrote:

Hi Chunyan,

Just the minor fix to zeroing the stack local in sprd_set_termios()
and using dev_get_drvdata() in sprd_suspend()/sprd_resume().

ok, I see.

Regards,
Peter Hurley

On 01/23/2015 08:01 AM, Chunyan Zhang wrote:

quoted

Add a full sc9836-uart driver for SC9836 SoC which is based on the
spreadtrum sharkl64 platform.
This driver also support earlycon.

[...]

quoted

+static void sprd_set_termios(struct uart_port *port,
+                                 struct ktermios *termios,
+                                 struct ktermios *old)
+{
+     unsigned int baud, quot;
+     unsigned int lcr, fc;

        unsigned int lcr = 0, fc;

quoted

+     unsigned long flags;
+
+     /* ask the core to calculate the divisor for us */
+     baud = uart_get_baud_rate(port, termios, old, 0, SPRD_BAUD_IO_LIMIT);
+
+     quot = (unsigned int)((port->uartclk + baud / 2) / baud);
+
+     /* set data length */
+     switch (termios->c_cflag & CSIZE) {
+     case CS5:
+             lcr |= SPRD_LCR_DATA_LEN5;
+             break;
+     case CS6:
+             lcr |= SPRD_LCR_DATA_LEN6;
+             break;
+     case CS7:
+             lcr |= SPRD_LCR_DATA_LEN7;
+             break;
+     case CS8:
+     default:
+             lcr |= SPRD_LCR_DATA_LEN8;
+             break;
+     }
+
+     /* calculate stop bits */
+     lcr &= ~(SPRD_LCR_STOP_1BIT | SPRD_LCR_STOP_2BIT);
+     if (termios->c_cflag & CSTOPB)
+             lcr |= SPRD_LCR_STOP_2BIT;
+     else
+             lcr |= SPRD_LCR_STOP_1BIT;
+
+     /* calculate parity */
+     lcr &= ~SPRD_LCR_PARITY;
+     termios->c_cflag &= ~CMSPAR;    /* no support mark/space */
+     if (termios->c_cflag & PARENB) {
+             lcr |= SPRD_LCR_PARITY_EN;
+             if (termios->c_cflag & PARODD)
+                     lcr |= SPRD_LCR_ODD_PAR;
+             else
+                     lcr |= SPRD_LCR_EVEN_PAR;
+     }

[...]

quoted

+static int sprd_probe(struct platform_device *pdev)
+{
+     struct resource *res;
+     struct uart_port *up;
+     struct clk *clk;
+     int irq;
+     int index;
+     int ret;
+
+     for (index = 0; index < ARRAY_SIZE(sprd_port); index++)
+             if (sprd_port[index] == NULL)
+                     break;
+
+     if (index == ARRAY_SIZE(sprd_port))
+             return -EBUSY;
+
+     index = sprd_probe_dt_alias(index, &pdev->dev);
+
+     sprd_port[index] = devm_kzalloc(&pdev->dev,
+             sizeof(*sprd_port[index]), GFP_KERNEL);
+     if (!sprd_port[index])
+             return -ENOMEM;
+
+     pdev->id = index;

see my recent reply regarding this and sprd_suspend/sprd_resume.

quoted

+
+     up = &sprd_port[index]->port;
+     up->dev = &pdev->dev;
+     up->line = index;
+     up->type = PORT_SPRD;
+     up->iotype = SERIAL_IO_PORT;
+     up->uartclk = SPRD_DEF_RATE;
+     up->fifosize = SPRD_FIFO_SIZE;
+     up->ops = &serial_sprd_ops;
+     up->flags = UPF_BOOT_AUTOCONF;
+
+     clk = devm_clk_get(&pdev->dev, NULL);
+     if (!IS_ERR(clk))
+             up->uartclk = clk_get_rate(clk);
+
+     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+     if (!res) {
+             dev_err(&pdev->dev, "not provide mem resource\n");
+             return -ENODEV;
+     }
+     up->mapbase = res->start;
+     up->membase = devm_ioremap_resource(&pdev->dev, res);
+     if (IS_ERR(up->membase))
+             return PTR_ERR(up->membase);
+
+     irq = platform_get_irq(pdev, 0);
+     if (irq < 0) {
+             dev_err(&pdev->dev, "not provide irq resource\n");
+             return -ENODEV;
+     }
+     up->irq = irq;
+
+     if (!sprd_ports_num) {
+             ret = uart_register_driver(&sprd_uart_driver);
+             if (ret < 0) {
+                     pr_err("Failed to register SPRD-UART driver\n");
+                     return ret;
+             }
+     }
+     sprd_ports_num++;
+
+     ret = uart_add_one_port(&sprd_uart_driver, up);
+     if (ret) {
+             sprd_port[index] = NULL;
+             sprd_remove(pdev);
+     }
+
+     platform_set_drvdata(pdev, up);
+
+     return ret;
+}
+
+static int sprd_suspend(struct device *dev)
+{
+     int id = to_platform_device(dev)->id;
+     struct uart_port *port = &sprd_port[id]->port;
+
+     uart_suspend_port(&sprd_uart_driver, port);

same comment: see my recent reply using dev_get_drvdata().

ok, i see. thanks!

Chunyan

quoted

+
+     return 0;
+}
+
+static int sprd_resume(struct device *dev)
+{
+     int id = to_platform_device(dev)->id;
+     struct uart_port *port = &sprd_port[id]->port;
+
+     uart_resume_port(&sprd_uart_driver, port);
+
+     return 0;
+}
+

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