[PATCH v4] drivers/misc: (aspeed-lpc-snoop): Add ast2400 to compat

[Patrick Venture]

This driver can be used on the aspeed ast2400 with minor
modifications.

Tested: ast2400 on quanta-q71l

Signed-off-by: Patrick Venture <vent...@google.com>
---
v4: fix the 2400/2500 data as they were backwards.
v3: added .data object to determine behavior difference between ast2400 and
    ast2500.
v2: added aspeed-g5 area because ast2400 doesn't use those bits.
    also updated commit message.
---
 drivers/misc/aspeed-lpc-snoop.c | 34 +++++++++++++++++++++++++++++-----
 1 file changed, 29 insertions(+), 5 deletions(-)

diff --git a/drivers/misc/aspeed-lpc-snoop.c b/drivers/misc/aspeed-lpc-snoop.c
index 593905565b74..cb78c98bc78d 100644
--- a/drivers/misc/aspeed-lpc-snoop.c
+++ b/drivers/misc/aspeed-lpc-snoop.c
@@ -20,6 +20,7 @@
 #include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 
@@ -51,6 +52,13 @@
 #define HICRB_ENSNP0D          BIT(14)
 #define HICRB_ENSNP1D          BIT(15)
 
+struct aspeed_lpc_snoop_model_data {
+       /* The ast2400 has bits 14 and 15 as reserved, whereas the ast2500
+        * can use them.
+        */
+       unsigned int has_hicrb_ensnp;
+};
+
 struct aspeed_lpc_snoop {
        struct regmap           *regmap;
        int                     irq;
@@ -123,10 +131,13 @@ static int aspeed_lpc_snoop_config_irq(struct 
aspeed_lpc_snoop *lpc_snoop,
 }
 
 static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop,
-                                 int channel, u16 lpc_port)
+                                  struct device *dev,
+                                  int channel, u16 lpc_port)
 {
        int rc = 0;
        u32 hicr5_en, snpwadr_mask, snpwadr_shift, hicrb_en;
+       const struct aspeed_lpc_snoop_model_data *model_data =
+               of_device_get_match_data(dev);
 
        /* Create FIFO datastructure */
        rc = kfifo_alloc(&lpc_snoop->snoop_fifo[channel],
@@ -155,7 +166,9 @@ static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop 
*lpc_snoop,
        regmap_update_bits(lpc_snoop->regmap, HICR5, hicr5_en, hicr5_en);
        regmap_update_bits(lpc_snoop->regmap, SNPWADR, snpwadr_mask,
                           lpc_port << snpwadr_shift);
-       regmap_update_bits(lpc_snoop->regmap, HICRB, hicrb_en, hicrb_en);
+       if (model_data->has_hicrb_ensnp)
+               regmap_update_bits(lpc_snoop->regmap, HICRB,
+                               hicrb_en, hicrb_en);
 
        return rc;
 }
@@ -213,14 +226,14 @@ static int aspeed_lpc_snoop_probe(struct platform_device 
*pdev)
        if (rc)
                return rc;
 
-       rc = aspeed_lpc_enable_snoop(lpc_snoop, 0, port);
+       rc = aspeed_lpc_enable_snoop(lpc_snoop, dev, 0, port);
        if (rc)
                return rc;
 
        /* Configuration of 2nd snoop channel port is optional */
        if (of_property_read_u32_index(dev->of_node, "snoop-ports",
                                       1, &port) == 0) {
-               rc = aspeed_lpc_enable_snoop(lpc_snoop, 1, port);
+               rc = aspeed_lpc_enable_snoop(lpc_snoop, dev, 1, port);
                if (rc)
                        aspeed_lpc_disable_snoop(lpc_snoop, 0);
        }
@@ -239,8 +252,19 @@ static int aspeed_lpc_snoop_remove(struct platform_device 
*pdev)
        return 0;
 }
 
+static const struct aspeed_lpc_snoop_model_data ast2400_model_data = {
+       .has_hicrb_ensnp = 0,
+};
+
+static const struct aspeed_lpc_snoop_model_data ast2500_model_data = {
+       .has_hicrb_ensnp = 1,
+};
+
 static const struct of_device_id aspeed_lpc_snoop_match[] = {
-       { .compatible = "aspeed,ast2500-lpc-snoop" },
+       { .compatible = "aspeed,ast2400-lpc-snoop",
+         .data = &ast2400_model_data },
+       { .compatible = "aspeed,ast2500-lpc-snoop",
+         .data = &ast2500_model_data },
        { },
 };
 
-- 
2.13.2.725.g09c95d1e9-goog