of serial port driver - add clk_get_rate() support
Currently this driver expects the clock-frequency attribute. This patch allows getting clock-frequency through clk driver API clk_get_rate() if clock-frequency attribute is not defined. So in the device bindings for serial device, one can add clocks phandle to refer to the clk device to get the rate. Signed-off-by: Murali Karicheri <m-karicheri2@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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parent
cadf748690
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0bbeb3c3e8
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@ -21,8 +21,10 @@
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#include <linux/of_serial.h>
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#include <linux/of_platform.h>
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#include <linux/nwpserial.h>
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#include <linux/clk.h>
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struct of_serial_info {
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struct clk *clk;
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int type;
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int line;
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};
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@ -51,7 +53,8 @@ EXPORT_SYMBOL_GPL(tegra_serial_handle_break);
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* Fill a struct uart_port for a given device node
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*/
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static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
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int type, struct uart_port *port)
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int type, struct uart_port *port,
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struct of_serial_info *info)
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{
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struct resource resource;
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struct device_node *np = ofdev->dev.of_node;
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@ -60,8 +63,17 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
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memset(port, 0, sizeof *port);
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if (of_property_read_u32(np, "clock-frequency", &clk)) {
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dev_warn(&ofdev->dev, "no clock-frequency property set\n");
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return -ENODEV;
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/* Get clk rate through clk driver if present */
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info->clk = clk_get(&ofdev->dev, NULL);
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if (info->clk == NULL) {
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dev_warn(&ofdev->dev,
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"clk or clock-frequency not defined\n");
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return -ENODEV;
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}
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clk_prepare_enable(info->clk);
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clk = clk_get_rate(info->clk);
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}
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/* If current-speed was set, then try not to change it. */
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if (of_property_read_u32(np, "current-speed", &spd) == 0)
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@ -70,7 +82,7 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
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ret = of_address_to_resource(np, 0, &resource);
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if (ret) {
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dev_warn(&ofdev->dev, "invalid address\n");
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return ret;
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goto out;
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}
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spin_lock_init(&port->lock);
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@ -97,7 +109,8 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
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default:
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dev_warn(&ofdev->dev, "unsupported reg-io-width (%d)\n",
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prop);
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return -EINVAL;
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ret = -EINVAL;
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goto out;
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}
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}
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@ -115,6 +128,10 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
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port->handle_break = tegra_serial_handle_break;
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return 0;
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out:
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if (info->clk)
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clk_disable_unprepare(info->clk);
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return ret;
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}
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/*
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@ -141,7 +158,7 @@ static int __devinit of_platform_serial_probe(struct platform_device *ofdev)
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return -ENOMEM;
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port_type = (unsigned long)match->data;
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ret = of_platform_serial_setup(ofdev, port_type, &port);
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ret = of_platform_serial_setup(ofdev, port_type, &port, info);
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if (ret)
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goto out;
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@ -204,6 +221,9 @@ static int of_platform_serial_remove(struct platform_device *ofdev)
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/* need to add code for these */
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break;
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}
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if (info->clk)
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clk_disable_unprepare(info->clk);
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kfree(info);
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return 0;
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}
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