[PATCH v5 05/17] clk: mpc512x: add backwards compat to the CCF code
Gerhard Sittig
gsi at denx.de
Sun Nov 17 18:06:05 EST 2013
extend the recently added COMMON_CLK platform support for MPC512x such
that it works with incomplete device tree data which lacks clock specs
Cc: Mike Turquette <mturquette at linaro.org>
Cc: Anatolij Gustschin <agust at denx.de>
Cc: linux-arm-kernel at lists.infradead.org
Cc: linuxppc-dev at lists.ozlabs.org
Signed-off-by: Gerhard Sittig <gsi at denx.de>
---
arch/powerpc/platforms/512x/clock-commonclk.c | 173 ++++++++++++++++++++++++-
1 file changed, 172 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/platforms/512x/clock-commonclk.c b/arch/powerpc/platforms/512x/clock-commonclk.c
index ddbeaec79246..c1faf3a9ea1f 100644
--- a/arch/powerpc/platforms/512x/clock-commonclk.c
+++ b/arch/powerpc/platforms/512x/clock-commonclk.c
@@ -11,6 +11,7 @@
* (at your option) any later version.
*/
+#include <linux/bitops.h>
#include <linux/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/device.h>
@@ -744,7 +745,177 @@ static void mpc5121_clk_provide_migration_support(void)
*/
static void mpc5121_clk_provide_backwards_compat(void)
{
- /* TODO */
+ enum did_reg_flags {
+ DID_REG_PSC = BIT(0),
+ DID_REG_PSCFIFO = BIT(1),
+ DID_REG_NFC = BIT(2),
+ DID_REG_CAN = BIT(3),
+ DID_REG_I2C = BIT(4),
+ DID_REG_DIU = BIT(5),
+ DID_REG_VIU = BIT(6),
+ DID_REG_FEC = BIT(7),
+ DID_REG_USB = BIT(8),
+ DID_REG_PATA = BIT(9),
+ };
+
+ int did_register;
+ struct device_node *np;
+ struct resource res;
+ int idx;
+ char devname[32];
+
+ /*
+ * those macros are not exactly pretty, but they encapsulate a lot
+ * of copy'n'paste heavy code which is even more ugly, and reduce
+ * the potential for inconsistencies in those many code copies
+ */
+
+#define FOR_NODES(compatname) \
+ for_each_compatible_node(np, NULL, compatname)
+
+#define NODE_PREP do { \
+ of_address_to_resource(np, 0, &res); \
+ snprintf(devname, sizeof(devname), "%08x.%s", res.start, np->name); \
+} while (0)
+
+#define NODE_CHK(clkname, clkitem, regnode, regflag) do { \
+ struct clk *clk; \
+ clk = of_clk_get_by_name(np, clkname); \
+ if (IS_ERR(clk)) { \
+ clk = clkitem; \
+ clk_register_clkdev(clk, clkname, devname); \
+ if (regnode) \
+ clk_register_clkdev(clk, clkname, np->name); \
+ did_register |= DID_REG_ ## regflag; \
+ pr_debug("clock alias name '%s' for dev '%s' pointer %p\n", \
+ clkname, devname, clk); \
+ } else { \
+ clk_put(clk); \
+ } \
+} while (0)
+
+ did_register = 0;
+
+ FOR_NODES(mpc512x_select_psc_compat()) {
+ NODE_PREP;
+ idx = (res.start >> 8) & 0xf;
+ NODE_CHK("ipg", clks[MPC512x_CLK_PSC0 + idx], 0, PSC);
+ NODE_CHK("mclk", clks[MPC512x_CLK_PSC0_MCLK + idx], 0, PSC);
+ }
+
+ FOR_NODES("fsl,mpc5121-psc-fifo") {
+ NODE_PREP;
+ NODE_CHK("ipg", clks[MPC512x_CLK_PSC_FIFO], 1, PSCFIFO);
+ }
+
+ FOR_NODES("fsl,mpc5121-nfc") {
+ NODE_PREP;
+ NODE_CHK("ipg", clks[MPC512x_CLK_NFC], 0, NFC);
+ }
+
+ FOR_NODES("fsl,mpc5121-mscan") {
+ NODE_PREP;
+ idx = 0;
+ idx += (res.start & 0x2000) ? 2 : 0;
+ idx += (res.start & 0x0080) ? 1 : 0;
+ NODE_CHK("ipg", clks[MPC512x_CLK_BDLC], 0, CAN);
+ NODE_CHK("mclk", clks[MPC512x_CLK_MSCAN0_MCLK + idx], 0, CAN);
+ }
+
+ /*
+ * do register the 'ips', 'sys', and 'ref' names globally
+ * instead of inside each individual CAN node, as there is no
+ * potential for a name conflict (in contrast to 'ipg' and 'mclk')
+ */
+ if (did_register & DID_REG_CAN) {
+ clk_register_clkdev(clks[MPC512x_CLK_IPS], "ips", NULL);
+ clk_register_clkdev(clks[MPC512x_CLK_SYS], "sys", NULL);
+ clk_register_clkdev(clks[MPC512x_CLK_REF], "ref", NULL);
+ }
+
+ FOR_NODES("fsl,mpc5121-i2c") {
+ NODE_PREP;
+ NODE_CHK("ipg", clks[MPC512x_CLK_I2C], 0, I2C);
+ }
+
+ /*
+ * workaround for the fact that the I2C driver does an "anonymous"
+ * lookup (NULL name spec, which yields the first clock spec) for
+ * which we cannot register an alias -- a _global_ 'ipg' alias that
+ * is not bound to any device name and returns the I2C clock item
+ * is not a good idea
+ *
+ * so we have the lookup in the peripheral driver fail, which is
+ * silent and non-fatal, and pre-enable the clock item here such
+ * that register access is possible
+ *
+ * see commit b3bfce2b "i2c: mpc: cleanup clock API use" for
+ * details, adjusting s/NULL/"ipg"/ in i2c-mpc.c would make this
+ * workaround obsolete
+ */
+ if (did_register & DID_REG_I2C)
+ clk_prepare_enable(clks[MPC512x_CLK_I2C]);
+
+ FOR_NODES("fsl,mpc5121-diu") {
+ NODE_PREP;
+ NODE_CHK("ipg", clks[MPC512x_CLK_DIU], 1, DIU);
+ }
+
+ FOR_NODES("fsl,mpc5121-viu") {
+ NODE_PREP;
+ NODE_CHK("ipg", clks[MPC512x_CLK_VIU], 0, VIU);
+ }
+
+ /*
+ * note that 2771399a "fs_enet: cleanup clock API use" did use the
+ * "per" string for the clock lookup in contrast to the "ipg" name
+ * which most other nodes are using -- this is not a fatal thing
+ * but just something to keep in mind when doing compatibility
+ * registration, it's a non-issue with up-to-date device tree data
+ */
+ FOR_NODES("fsl,mpc5121-fec") {
+ NODE_PREP;
+ NODE_CHK("per", clks[MPC512x_CLK_FEC], 0, FEC);
+ }
+ FOR_NODES("fsl,mpc5121-fec-mdio") {
+ NODE_PREP;
+ NODE_CHK("per", clks[MPC512x_CLK_FEC], 0, FEC);
+ }
+
+ FOR_NODES("fsl,mpc5121-usb2-dr") {
+ NODE_PREP;
+ idx = (res.start & 0x4000) ? 1 : 0;
+ NODE_CHK("ipg", clks[MPC512x_CLK_USB1 + idx], 0, USB);
+ }
+
+ FOR_NODES("fsl,mpc5121-pata") {
+ NODE_PREP;
+ NODE_CHK("ipg", clks[MPC512x_CLK_PATA], 0, PATA);
+ }
+
+ /*
+ * try to collapse diagnostics into a single line of output yet
+ * provide a full list of what is missing, to avoid noise in the
+ * absence of up-to-date device tree data -- backwards
+ * compatibility to old DTBs is a requirement, updates may be
+ * desirable or preferrable but are not at all mandatory
+ */
+ if (did_register) {
+ pr_notice("device tree lacks clock specs, adding fallbacks (0x%x,%s%s%s%s%s%s%s%s%s%s)\n",
+ did_register,
+ (did_register & DID_REG_PSC) ? " PSC" : "",
+ (did_register & DID_REG_PSCFIFO) ? " PSCFIFO" : "",
+ (did_register & DID_REG_NFC) ? " NFC" : "",
+ (did_register & DID_REG_CAN) ? " CAN" : "",
+ (did_register & DID_REG_I2C) ? " I2C" : "",
+ (did_register & DID_REG_DIU) ? " DIU" : "",
+ (did_register & DID_REG_VIU) ? " VIU" : "",
+ (did_register & DID_REG_FEC) ? " FEC" : "",
+ (did_register & DID_REG_USB) ? " USB" : "",
+ (did_register & DID_REG_PATA) ? " PATA" : "");
+ } else {
+ pr_debug("device tree has clock specs, no fallbacks added\n");
+ }
}
int __init mpc5121_clk_init(void)
--
1.7.10.4
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