| Message ID | 1385851897-23475-11-git-send-email-gsi@denx.de (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Anatolij Gustschin |
| Headers | show |
On Sat, Nov 30, 2013 at 11:51:30PM +0100, Gerhard Sittig wrote: > prepare and enable the FIFO clock upon PSC FIFO initialization, > check for and propagage errors when enabling the PSC FIFO clock, > disable and unprepare the FIFO clock upon PSC FIFO uninitialization > > devm_{get,put}_clk() doesn't apply here, as the SoC provides a > single FIFO component which is shared among several PSC components, > thus the FIFO isn't associated with a device (while the PSCs are) > > provide a fallback clock lookup approach in case the OF based clock > lookup for the PSC FIFO fails, this allows for successful operation in > the presence of an outdated device tree which lacks clock specs > > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: Jiri Slaby <jslaby@suse.cz> > Cc: linux-serial@vger.kernel.org > Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> # for v4 > Signed-off-by: Gerhard Sittig <gsi@denx.de> > --- > Greg, the addition since v4 is the clk_get_sys() call for the 'ipg' > clock item (backwards compat for device trees w/o clock specs) That's fine, my ACK still stands. thanks, greg k-h
On Sat, 30 Nov 2013 23:51:30 +0100 Gerhard Sittig <gsi@denx.de> wrote: > prepare and enable the FIFO clock upon PSC FIFO initialization, > check for and propagage errors when enabling the PSC FIFO clock, > disable and unprepare the FIFO clock upon PSC FIFO uninitialization > > devm_{get,put}_clk() doesn't apply here, as the SoC provides a > single FIFO component which is shared among several PSC components, > thus the FIFO isn't associated with a device (while the PSCs are) > > provide a fallback clock lookup approach in case the OF based clock > lookup for the PSC FIFO fails, this allows for successful operation in > the presence of an outdated device tree which lacks clock specs > > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: Jiri Slaby <jslaby@suse.cz> > Cc: linux-serial@vger.kernel.org > Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> # for v4 > Signed-off-by: Gerhard Sittig <gsi@denx.de> > --- > Greg, the addition since v4 is the clk_get_sys() call for the 'ipg' > clock item (backwards compat for device trees w/o clock specs) > > --- > drivers/tty/serial/mpc52xx_uart.c | 50 ++++++++++++++++++++++++++++++++----- > 1 file changed, 44 insertions(+), 6 deletions(-) applied to next. Thanks! Anatolij
diff --git a/drivers/tty/serial/mpc52xx_uart.c b/drivers/tty/serial/mpc52xx_uart.c index 6345f377a246..97888f4900ec 100644 --- a/drivers/tty/serial/mpc52xx_uart.c +++ b/drivers/tty/serial/mpc52xx_uart.c @@ -421,6 +421,7 @@ struct psc_fifoc { static struct psc_fifoc __iomem *psc_fifoc; static unsigned int psc_fifoc_irq; +static struct clk *psc_fifoc_clk; static void mpc512x_psc_fifo_init(struct uart_port *port) { @@ -568,36 +569,73 @@ static unsigned int mpc512x_psc_set_baudrate(struct uart_port *port, /* Init PSC FIFO Controller */ static int __init mpc512x_psc_fifoc_init(void) { + int err; struct device_node *np; + struct clk *clk; + + /* default error code, potentially overwritten by clock calls */ + err = -ENODEV; np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-psc-fifo"); if (!np) { pr_err("%s: Can't find FIFOC node\n", __func__); - return -ENODEV; + goto out_err; + } + + clk = of_clk_get(np, 0); + if (IS_ERR(clk)) { + /* backwards compat with device trees that lack clock specs */ + clk = clk_get_sys(np->name, "ipg"); + } + if (IS_ERR(clk)) { + pr_err("%s: Can't lookup FIFO clock\n", __func__); + err = PTR_ERR(clk); + goto out_ofnode_put; + } + if (clk_prepare_enable(clk)) { + pr_err("%s: Can't enable FIFO clock\n", __func__); + clk_put(clk); + goto out_ofnode_put; } + psc_fifoc_clk = clk; psc_fifoc = of_iomap(np, 0); if (!psc_fifoc) { pr_err("%s: Can't map FIFOC\n", __func__); - of_node_put(np); - return -ENODEV; + goto out_clk_disable; } psc_fifoc_irq = irq_of_parse_and_map(np, 0); - of_node_put(np); if (psc_fifoc_irq == 0) { pr_err("%s: Can't get FIFOC irq\n", __func__); - iounmap(psc_fifoc); - return -ENODEV; + goto out_unmap; } + of_node_put(np); return 0; + +out_unmap: + iounmap(psc_fifoc); +out_clk_disable: + clk_disable_unprepare(psc_fifoc_clk); + clk_put(psc_fifoc_clk); +out_ofnode_put: + of_node_put(np); +out_err: + return err; } static void __exit mpc512x_psc_fifoc_uninit(void) { iounmap(psc_fifoc); + + /* disable the clock, errors are not fatal */ + if (psc_fifoc_clk) { + clk_disable_unprepare(psc_fifoc_clk); + clk_put(psc_fifoc_clk); + psc_fifoc_clk = NULL; + } } /* 512x specific interrupt handler. The caller holds the port lock */
prepare and enable the FIFO clock upon PSC FIFO initialization, check for and propagage errors when enabling the PSC FIFO clock, disable and unprepare the FIFO clock upon PSC FIFO uninitialization devm_{get,put}_clk() doesn't apply here, as the SoC provides a single FIFO component which is shared among several PSC components, thus the FIFO isn't associated with a device (while the PSCs are) provide a fallback clock lookup approach in case the OF based clock lookup for the PSC FIFO fails, this allows for successful operation in the presence of an outdated device tree which lacks clock specs Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: linux-serial@vger.kernel.org Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> # for v4 Signed-off-by: Gerhard Sittig <gsi@denx.de> --- Greg, the addition since v4 is the clk_get_sys() call for the 'ipg' clock item (backwards compat for device trees w/o clock specs) --- drivers/tty/serial/mpc52xx_uart.c | 50 ++++++++++++++++++++++++++++++++----- 1 file changed, 44 insertions(+), 6 deletions(-)