[PATCH 07/10] spi: espi_amd: Add eSPI set frequency IOCTL command

[Raju Rangoju <Raju.Rangoju@xxxxxxx>]

This patch adds support for a new IOCTL command in the espi_amd driver to
set the operating frequency of the eSPI controller. The frequency value
can be one of the following supported options: 16MHz, 33MHz or 66MHz.

Co-developed-by: Krishnamoorthi M <krishnamoorthi.m@xxxxxxx>
Signed-off-by: Krishnamoorthi M <krishnamoorthi.m@xxxxxxx>
Co-developed-by: Akshata MukundShetty <akshata.mukundshetty@xxxxxxx>
Signed-off-by: Akshata MukundShetty <akshata.mukundshetty@xxxxxxx>
Signed-off-by: Raju Rangoju <Raju.Rangoju@xxxxxxx>
---
 drivers/spi/espi-amd-dev.c | 40 ++++++++++++++++++++++++++++++++++++++
 drivers/spi/espi-amd.h     |  1 +
 2 files changed, 41 insertions(+)

diff --git a/drivers/spi/espi-amd-dev.c b/drivers/spi/espi-amd-dev.c
index c78a9b2b059b..9f1968566980 100644
--- a/drivers/spi/espi-amd-dev.c
+++ b/drivers/spi/espi-amd-dev.c
@@ -249,6 +249,43 @@ static int amd_espi_ioctl_set_channel_mode(struct amd_espi *amd_espi, unsigned l
 	return ret;
 }
 
+static int amd_espi_ioctl_set_freq(struct amd_espi *amd_espi, unsigned long arg)
+{
+	u32 ctrlr_config, slave_config;
+	struct config *config;
+	int ret;
+
+	config = kzalloc(sizeof(*config), GFP_KERNEL);
+	if (!config)
+		return -ENOMEM;
+
+	if (copy_from_user(config, (void __user *)arg, sizeof(struct config))) {
+		ret = -EFAULT;
+		goto set_freq_free;
+	}
+
+	ctrlr_config = readl(ESPI_BASE + AMD_ESPI_SLAVE0_CONFIG_REG);
+
+	ret = amd_espi_get_general_config(amd_espi, &slave_config);
+	if (ret != CB_SUCCESS)
+		goto set_freq_free;
+
+	ret = amd_espi_set_freqmode(amd_espi, &slave_config, &ctrlr_config, config->op_freq);
+	if (ret != CB_SUCCESS)
+		goto set_freq_free;
+
+	ret = amd_espi_set_config(amd_espi, slave_config, ESPI_SLAVE_GENERAL_CAPS_CFG);
+	if (ret != CB_SUCCESS) {
+		dev_err(amd_espi->dev, "Set operating frequency failed\n");
+		goto set_freq_free;
+	}
+	writel(ctrlr_config, (ESPI_BASE + AMD_ESPI_SLAVE0_CONFIG_REG));
+
+set_freq_free:
+	kfree(config);
+	return ret;
+}
+
 static long amd_espi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct amd_espi *amd_espi = filp->private_data;
@@ -276,6 +313,9 @@ static long amd_espi_ioctl(struct file *filp, unsigned int cmd, unsigned long ar
 	case ESPI_SET_CHAN_MODE:
 		ret = amd_espi_ioctl_set_channel_mode(amd_espi, arg);
 		break;
+	case  ESPI_SET_FREQ:
+		ret = amd_espi_ioctl_set_freq(amd_espi, arg);
+		break;
 	default:
 		dev_err(amd_espi->dev, "ESPI command not found, returning error\n");
 		ret = -EINVAL;
diff --git a/drivers/spi/espi-amd.h b/drivers/spi/espi-amd.h
index 3774918d994f..e5760db7c1d3 100644
--- a/drivers/spi/espi-amd.h
+++ b/drivers/spi/espi-amd.h
@@ -145,6 +145,7 @@
 #define ESPI_INBAND_RESET            _IO(ESPI_MAGIC_NUMBER, 0x3)
 #define ESPI_SET_IO_MODE             _IOW(ESPI_MAGIC_NUMBER, 0x4, struct config)
 #define ESPI_SET_CHAN_MODE           _IOW(ESPI_MAGIC_NUMBER, 0x5, struct config)
+#define ESPI_SET_FREQ                _IOW(ESPI_MAGIC_NUMBER, 0x6, struct config)
 
 /*
  * enum amd_espi_versions - eSPI controller versions
-- 
2.34.1