mfd: qcom_rpm: write fw_version to CTRL_REG

BugLink: https://bugs.launchpad.net/bugs/1822271

[ Upstream commit 504e4175 ]

This is required as part of the initialization sequence on certain SoCs.

If these registers are not initialized, the hardware can be unresponsive.
This fixes the driver on apq8060 (HP TouchPad device).
Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Juerg Haefliger <juerg.haefliger@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/mfd/qcom_rpm.c

@@ -570,6 +570,10 @@ static int qcom_rpm_probe(struct platform_device *pdev)
 		return -EFAULT;
 	}
 
+	writel(fw_version[0], RPM_CTRL_REG(rpm, 0));
+	writel(fw_version[1], RPM_CTRL_REG(rpm, 1));
+	writel(fw_version[2], RPM_CTRL_REG(rpm, 2));
+
 	dev_info(&pdev->dev, "RPM firmware %u.%u.%u\n", fw_version[0],
 							fw_version[1],
 							fw_version[2]);