Thread (9 messages) 9 messages, 4 authors, 2014-11-24

[PATCH v4 1/2] i2c: s3c2410: Handle i2c sys_cfg register in i2c driver

From: Wolfram Sang <hidden>
Date: 2014-11-21 07:25:45
Also in: linux-devicetree, linux-i2c, linux-samsung-soc

On Thu, Oct 30, 2014 at 01:34:29PM +0530, Pankaj Dubey wrote:
Let's handle i2c interrupt re-configuration in i2c driver. This will
help us in removing some soc specific checks from machine files and
will help in removing static iomapping of SYS register in exynos.c

Since only Exynos5250, and Exynos5420 has i2c nodes in DT, added syscon
based phandle to i2c device nodes of respective SoC DT files.

Also handle saving and restoring of SYS_I2C_CFG register during
suspend and resume of i2c driver.

CC: Rob Herring <robh+dt@kernel.org>
CC: Randy Dunlap <redacted>
CC: Wolfram Sang <redacted>
CC: Russell King <redacted>
CC: devicetree at vger.kernel.org
CC: linux-doc at vger.kernel.org
CC: linux-i2c at vger.kernel.org
Signed-off-by: Pankaj Dubey <redacted>
---
 .../devicetree/bindings/i2c/i2c-s3c2410.txt        |    1 +
 arch/arm/boot/dts/exynos5250.dtsi                  |    4 +++
 arch/arm/boot/dts/exynos5420.dtsi                  |    4 +++
I usually don't take DTS patches. They should go via arm-soc. Please say
so if there are reasons I should take them.
quoted hunk ↗ jump to hunk
@@ -1084,6 +1092,23 @@ s3c24xx_i2c_parse_dt(struct device_node *np, struct s3c24xx_i2c *i2c)
 	of_property_read_u32(np, "samsung,i2c-slave-addr", &pdata->slave_addr);
 	of_property_read_u32(np, "samsung,i2c-max-bus-freq",
 				(u32 *)&pdata->frequency);
+	/*
+	 * Exynos5's legacy i2c controller and new high speed i2c
+	 * controller have muxed interrupt sources. By default the
+	 * interrupts for 4-channel HS-I2C controller are enabled.
+	 * If node for first four channels of legacy i2c controller
s/node/nodes/
+	 * are available then re-configure the interrupts via the
+	 * system register.
+	 */
+	id = of_alias_get_id(np, "i2c");
+	i2c->sysreg = syscon_regmap_lookup_by_phandle(np,
+			"samsung,sysreg-phandle");
+	if (IS_ERR(i2c->sysreg)) {
+		/* As this is not compulsory do not return error */
+		pr_info("i2c-%d skipping re-configuration of interrutps\n", id);
I'd say drop this message. If you want to keep it, it should be dev_dbg.
+		return;
+	}
+	regmap_update_bits(i2c->sysreg, EXYNOS5_SYS_I2C_CFG, BIT(id), 0);
 }
Rest looks good, thanks!
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