| Message ID | 1362694460-1919-2-git-send-email-maxime.ripard@free-electrons.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On Thu, Mar 07, 2013 at 11:14:15PM +0100, Maxime Ripard wrote: > From: Emilio López <emilio@elopez.com.ar> > > This commit implements support for using the "clocks" DT property, instead > of having to use clock-frequency. > > Signed-off-by: Emilio López <emilio@elopez.com.ar> > --- > drivers/tty/serial/8250/8250_dw.c | 32 ++++++++++++++++++++++---------- > 1 file changed, 22 insertions(+), 10 deletions(-) <snip> > @@ -137,8 +140,15 @@ static int dw8250_probe_of(struct uart_port *p) > p->regshift = val; > > if (of_property_read_u32(np, "clock-frequency", &val)) { > - dev_err(p->dev, "no clock-frequency property set\n"); > - return -EINVAL; > + /* Get clk rate through clk driver if present */ > + data->clk = clk_get(p->dev, NULL); > + if (IS_ERR(data->clk)) { > + dev_err(p->dev, "clk or clock-frequency not defined\n"); > + return -EINVAL; > + } > + > + clk_prepare_enable(data->clk); > + val = clk_get_rate(data->clk); Don't get the clk here.. > } > p->uartclk = val; > > @@ -300,6 +310,12 @@ static int dw8250_probe(struct platform_device *pdev) Get it here so it is then handled for also others besides DT users. And prefer devm_clk_get(). Something like this: ... uart.port.membase = ioremap(regs->start, resource_size(regs)); if (!uart.port.membase) return -ENOMEM; + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->clk = devm_clk_get(&pdev->dev, NULL); + clk_prepare_enable(data->clk); + uart.port.iotype = UPIO_MEM; uart.port.serial_in = dw8250_serial_in; uart.port.serial_out = dw8250_serial_out; + uart.port.private_data = data; + uart.port.uartclk = clk_get_rate(data->clk); dw8250_setup_port(&uart); ... Then in dw8250_probe_of() you need to use the "clock-frequency" property only when p->uartclk is 0. Thanks,
Hi Heikki Le 15/03/2013 13:56, Heikki Krogerus a écrit : >> @@ -137,8 +140,15 @@ static int dw8250_probe_of(struct uart_port *p) >> p->regshift = val; >> >> if (of_property_read_u32(np, "clock-frequency", &val)) { >> - dev_err(p->dev, "no clock-frequency property set\n"); >> - return -EINVAL; >> + /* Get clk rate through clk driver if present */ >> + data->clk = clk_get(p->dev, NULL); >> + if (IS_ERR(data->clk)) { >> + dev_err(p->dev, "clk or clock-frequency not defined\n"); >> + return -EINVAL; >> + } >> + >> + clk_prepare_enable(data->clk); >> + val = clk_get_rate(data->clk); > > Don't get the clk here.. > >> } >> p->uartclk = val; >> >> @@ -300,6 +310,12 @@ static int dw8250_probe(struct platform_device *pdev) > > Get it here so it is then handled for also others besides DT users. > And prefer devm_clk_get(). Something like this: > > ... > uart.port.membase = ioremap(regs->start, resource_size(regs)); > if (!uart.port.membase) > return -ENOMEM; > > + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->clk = devm_clk_get(&pdev->dev, NULL); > + clk_prepare_enable(data->clk); > + > uart.port.iotype = UPIO_MEM; > uart.port.serial_in = dw8250_serial_in; > uart.port.serial_out = dw8250_serial_out; > + uart.port.private_data = data; > + uart.port.uartclk = clk_get_rate(data->clk); > > dw8250_setup_port(&uart); > ... > > Then in dw8250_probe_of() you need to use the "clock-frequency" > property only when p->uartclk is 0. Thanks for your feedback. Emilio made a new version of this patch, I'll send it soon. Maxime
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index db0e66f..8f03800 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -26,6 +26,7 @@ #include <linux/platform_device.h> #include <linux/slab.h> #include <linux/acpi.h> +#include <linux/clk.h> #include "8250.h" @@ -55,8 +56,9 @@ struct dw8250_data { - int last_lcr; - int line; + int last_lcr; + int line; + struct clk *clk; }; static void dw8250_serial_out(struct uart_port *p, int offset, int value) @@ -116,6 +118,7 @@ static int dw8250_handle_irq(struct uart_port *p) static int dw8250_probe_of(struct uart_port *p) { struct device_node *np = p->dev->of_node; + struct dw8250_data *data = p->private_data; u32 val; if (!of_property_read_u32(np, "reg-io-width", &val)) { @@ -137,8 +140,15 @@ static int dw8250_probe_of(struct uart_port *p) p->regshift = val; if (of_property_read_u32(np, "clock-frequency", &val)) { - dev_err(p->dev, "no clock-frequency property set\n"); - return -EINVAL; + /* Get clk rate through clk driver if present */ + data->clk = clk_get(p->dev, NULL); + if (IS_ERR(data->clk)) { + dev_err(p->dev, "clk or clock-frequency not defined\n"); + return -EINVAL; + } + + clk_prepare_enable(data->clk); + val = clk_get_rate(data->clk); } p->uartclk = val; @@ -300,6 +310,12 @@ static int dw8250_probe(struct platform_device *pdev) dw8250_setup_port(&uart); + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + uart.port.private_data = data; + if (pdev->dev.of_node) { err = dw8250_probe_of(&uart.port); if (err) @@ -312,12 +328,6 @@ static int dw8250_probe(struct platform_device *pdev) return -ENODEV; } - data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); - if (!data) - return -ENOMEM; - - uart.port.private_data = data; - data->line = serial8250_register_8250_port(&uart); if (data->line < 0) return data->line; @@ -333,6 +343,8 @@ static int dw8250_remove(struct platform_device *pdev) serial8250_unregister_port(data->line); + clk_disable_unprepare(data->clk); + return 0; }