[PATCH v1 17/24] serial: mpc512x: setup the PSC FIFO clock as well

[Gerhard Sittig]

prepare and enable the FIFO clock upon PSC FIFO initialization, disable
and unprepare the FIFO clock upon PSC FIFO uninitialization, remove the
pre-enable workaround from the platform's clock driver

Signed-off-by: Gerhard Sittig <g...@denx.de>
---
 arch/powerpc/platforms/512x/clock-commonclk.c |    2 --
 drivers/tty/serial/mpc52xx_uart.c             |   47 +++++++++++++++++++++----
 2 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/platforms/512x/clock-commonclk.c 
b/arch/powerpc/platforms/512x/clock-commonclk.c
index 31707b5..2c6da07 100644
--- a/arch/powerpc/platforms/512x/clock-commonclk.c
+++ b/arch/powerpc/platforms/512x/clock-commonclk.c
@@ -690,8 +690,6 @@ static void mpc512x_clk_setup_clock_tree(int busfreq)
        clk_prepare_enable(clks[MPC512x_CLK_MEM]);      /* SRAM */
        clk_prepare_enable(clks[MPC512x_CLK_IPS]);      /* SoC periph */
        clk_prepare_enable(clks[MPC512x_CLK_LPC]);      /* boot media */
-       /* some are required yet no dependencies were declared */
-       clk_prepare_enable(clks[MPC512x_CLK_PSC_FIFO]);
        /* some are not yet acquired by their respective drivers */
        clk_prepare_enable(clks[MPC512x_CLK_PSC3_MCLK]);/* serial console */
        clk_prepare_enable(clks[MPC512x_CLK_FEC]);      /* network, NFS */
diff --git a/drivers/tty/serial/mpc52xx_uart.c 
b/drivers/tty/serial/mpc52xx_uart.c
index 221fb89..e67d4c0 100644
--- a/drivers/tty/serial/mpc52xx_uart.c
+++ b/drivers/tty/serial/mpc52xx_uart.c
@@ -567,35 +567,70 @@ static unsigned int mpc512x_psc_set_baudrate(struct 
uart_port *port,
 static int __init mpc512x_psc_fifoc_init(void)
 {
        struct device_node *np;
+       struct clk *clk;
 
        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_by_name(np, "per");
+       if (IS_ERR(clk)) {
+               pr_err("%s: Can't lookup FIFO clock\n", __func__);
+               goto out_ofnode_put;
+       }
+       if (clk_prepare_enable(clk)) {
+               pr_err("%s: Can't enable FIFO clock\n", __func__);
+               goto out_clk_put;
        }
 
        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;
        }
 
+       clk_put(clk);
+       of_node_put(np);
        return 0;
+
+out_unmap:
+       iounmap(psc_fifoc);
+out_clk_disable:
+       clk_disable_unprepare(clk);
+out_clk_put:
+       clk_put(clk);
+out_ofnode_put:
+       of_node_put(np);
+out_err:
+       return -ENODEV;
 }
 
 static void __exit mpc512x_psc_fifoc_uninit(void)
 {
+       struct device_node *np;
+       struct clk *clk;
+
        iounmap(psc_fifoc);
+
+       /* disable the clock, errors are not fatal */
+       np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-psc-fifo");
+       if (np) {
+               clk = of_clk_get_by_name(np, "per");
+               if (!IS_ERR(clk)) {
+                       clk_disable_unprepare(clk);
+                       clk_put(clk);
+               }
+               of_node_put(np);
+       }
 }
 
 /* 512x specific interrupt handler. The caller holds the port lock */
-- 
1.7.10.4

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