[PATCH v2 14/24] 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             |   39 +++++++++++++++++++++----
 2 files changed, 33 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/platforms/512x/clock-commonclk.c 
b/arch/powerpc/platforms/512x/clock-commonclk.c
index b822469..99d197d 100644
--- a/arch/powerpc/platforms/512x/clock-commonclk.c
+++ b/arch/powerpc/platforms/512x/clock-commonclk.c
@@ -689,8 +689,6 @@ 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 8643dcf..3fdadf9 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)
 {
@@ -574,30 +575,56 @@ static int __init mpc512x_psc_fifoc_init(void)
                                     "fsl,mpc5121-psc-fifo");
        if (!np) {
                pr_err("%s: Can't find FIFOC node\n", __func__);
-               return -ENODEV;
+               goto out_err;
+       }
+
+       psc_fifoc_clk = of_clk_get_by_name(np, "per");
+       if (IS_ERR(psc_fifoc_clk)) {
+               pr_err("%s: Can't lookup FIFO clock\n", __func__);
+               goto out_ofnode_put;
+       }
+       if (clk_prepare_enable(psc_fifoc_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;
        }
 
+       of_node_put(np);
        return 0;
+
+out_unmap:
+       iounmap(psc_fifoc);
+out_clk_disable:
+       clk_disable_unprepare(psc_fifoc_clk);
+out_clk_put:
+       clk_put(psc_fifoc_clk);
+out_ofnode_put:
+       of_node_put(np);
+out_err:
+       return -ENODEV;
 }
 
 static void __exit mpc512x_psc_fifoc_uninit(void)
 {
        iounmap(psc_fifoc);
+
+       /* disable the clock, errors are not fatal */
+       if (psc_fifoc_clk && !IS_ERR(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 */
-- 
1.7.10.4

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