[PATCH v3 1/5] x86: pmc_atom: export accessors to PMC registers

Andy Shevchenko
2015-07-06T14:29:15Z

Export pmc_atom_read() and pmc_atom_write() accessors to the PMC registers. On
early initcall stages the functions will return -ENODEV, and caller has to wait
when it will be available. Additionally make absence of debugfs a non-fatal
error.

The patch will be useful for the upcoming fixes regarding to LPSS block found
on Intel BayTrail-T and Braswell.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
arch/x86/include/asm/pmc_atom.h | 4 ++++
arch/x86/kernel/pmc_atom.c | 49 ++++++++++++++++++++++++++++-------------
2 files changed, 38 insertions(+), 15 deletions(-)

diff --git a/arch/x86/include/asm/pmc_atom.h b/arch/x86/include/asm/pmc_atom.h
index bc0fc08..6ee2200 100644
--- a/arch/x86/include/asm/pmc_atom.h
+++ b/arch/x86/include/asm/pmc_atom.h
@@ -126,4 +126,8 @@
#define SLEEP_TYPE_MASK 0xFFFFECFF
#define SLEEP_TYPE_S5 0x1C00
#define SLEEP_ENABLE 0x2000
+
+extern int pmc_atom_read(int offset, u32 *value);
+extern int pmc_atom_write(int offset, u32 value);
+
#endif /* PMC_ATOM_H */
diff --git a/arch/x86/kernel/pmc_atom.c b/arch/x86/kernel/pmc_atom.c
index d66a4fe..4e1242e 100644
--- a/arch/x86/kernel/pmc_atom.c
+++ b/arch/x86/kernel/pmc_atom.c
@@ -31,6 +31,7 @@ struct pmc_dev {
#ifdef CONFIG_DEBUG_FS
struct dentry *dbgfs_dir;
#endif /* CONFIG_DEBUG_FS */
+ bool init;
};

static struct pmc_dev pmc_device;
@@ -111,6 +112,30 @@ static inline void pmc_reg_write(struct pmc_dev *pmc, int reg_offset, u32 val)
writel(val, pmc->regmap + reg_offset);
}

+int pmc_atom_read(int offset, u32 *value)
+{
+ struct pmc_dev *pmc = &pmc_device;
+
+ if (!pmc->init)
+ return -ENODEV;
+
+ *value = pmc_reg_read(pmc, offset);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pmc_atom_read);
+
+int pmc_atom_write(int offset, u32 value)
+{
+ struct pmc_dev *pmc = &pmc_device;
+
+ if (!pmc->init)
+ return -ENODEV;
+
+ pmc_reg_write(pmc, offset, value);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pmc_atom_write);
+
static void pmc_power_off(void)
{
u16 pm1_cnt_port;
@@ -250,7 +275,7 @@ static void pmc_dbgfs_unregister(struct pmc_dev *pmc)
debugfs_remove_recursive(pmc->dbgfs_dir);
}

-static int pmc_dbgfs_register(struct pmc_dev *pmc, struct pci_dev *pdev)
+static int pmc_dbgfs_register(struct pmc_dev *pmc)
{
struct dentry *dir, *f;

@@ -262,24 +287,18 @@ static int pmc_dbgfs_register(struct pmc_dev *pmc, struct pci_dev *pdev)

f = debugfs_create_file("dev_state", S_IFREG | S_IRUGO,
dir, pmc, &pmc_dev_state_ops);
- if (!f) {
- dev_err(&pdev->dev, "dev_state register failed\n");
+ if (!f)
goto err;
- }

f = debugfs_create_file("pss_state", S_IFREG | S_IRUGO,
dir, pmc, &pmc_pss_state_ops);
- if (!f) {
- dev_err(&pdev->dev, "pss_state register failed\n");
+ if (!f)
goto err;
- }

f = debugfs_create_file("sleep_state", S_IFREG | S_IRUGO,
dir, pmc, &pmc_sleep_tmr_ops);
- if (!f) {
- dev_err(&pdev->dev, "sleep_state register failed\n");
+ if (!f)
goto err;
- }

return 0;
err:
@@ -287,7 +306,7 @@ err:
return -ENODEV;
}
#else
-static int pmc_dbgfs_register(struct pmc_dev *pmc, struct pci_dev *pdev)
+static int pmc_dbgfs_register(struct pmc_dev *pmc)
{
return 0;
}
@@ -318,11 +337,11 @@ static int pmc_setup_dev(struct pci_dev *pdev)
/* PMC hardware registers setup */
pmc_hw_reg_setup(pmc);

- ret = pmc_dbgfs_register(pmc, pdev);
- if (ret) {
- iounmap(pmc->regmap);
- }
+ ret = pmc_dbgfs_register(pmc);
+ if (ret)
+ dev_warn(&pdev->dev, "debugfs register failed\n");

+ pmc->init = true;
return ret;
}

--
2.1.4