clk: vc5: Add properties for configuring SD/OE behavior

The SD/OE pin may be configured to enable output when high or low, and
to shutdown the device when high. This behavior is controller by the SH
and SP bits of the Primary Source and Shutdown Register (and to a lesser
extent the OS and OE bits). By default, both bits are 0 (unless set by
OTP memory), but they may need to be configured differently, depending
on the external circuitry controlling the SD/OE pin.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Link: https://lore.kernel.org/r/20210809223813.3766204-3-sean.anderson@seco.com
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

diff --git a/drivers/clk/clk-versaclock5.c b/drivers/clk/clk-versaclock5.c
index a430128..c6d3b1a 100644 (file)
--- a/drivers/clk/clk-versaclock5.c
+++ b/drivers/clk/clk-versaclock5.c
@@ -907,6 +907,7 @@ static const struct of_device_id clk_vc5_of_match[];
 
 static int vc5_probe(struct i2c_client *client, const struct i2c_device_id *id)
 {
+       unsigned int oe, sd, src_mask = 0, src_val = 0;
        struct vc5_driver_data *vc5;
        struct clk_init_data init;
        const char *parent_names[2];
@@ -934,6 +935,29 @@ static int vc5_probe(struct i2c_client *client, const struct i2c_device_id *id)
                return dev_err_probe(&client->dev, PTR_ERR(vc5->regmap),
                                     "failed to allocate register map\n");
 
+       ret = of_property_read_u32(client->dev.of_node, "idt,shutdown", &sd);
+       if (!ret) {
+               src_mask |= VC5_PRIM_SRC_SHDN_EN_GBL_SHDN;
+               if (sd)
+                       src_val |= VC5_PRIM_SRC_SHDN_EN_GBL_SHDN;
+       } else if (ret != -EINVAL) {
+               return dev_err_probe(&client->dev, ret,
+                                    "could not read idt,shutdown\n");
+       }
+
+       ret = of_property_read_u32(client->dev.of_node,
+                                  "idt,output-enable-active", &oe);
+       if (!ret) {
+               src_mask |= VC5_PRIM_SRC_SHDN_SP;
+               if (oe)
+                       src_val |= VC5_PRIM_SRC_SHDN_SP;
+       } else if (ret != -EINVAL) {
+               return dev_err_probe(&client->dev, ret,
+                                    "could not read idt,output-enable-active\n");
+       }
+
+       regmap_update_bits(vc5->regmap, VC5_PRIM_SRC_SHDN, src_mask, src_val);
+
        /* Register clock input mux */
        memset(&init, 0, sizeof(init));