i2c: Blackfin TWI: make sure we don't end up with a CLKDIV=0
Make sure we don't end up with an invalid CLKDIV=0 in case someone specifies 20kHz SCL or less (5 * 1024 / 20 = 0x100). Signed-off-by: Michael Hennerich <michael.hennerich@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Bryan Wu <cooloney@kernel.org> [ben-linux@fluff.org: shortened subject line] Signed-off-by: Ben Dooks <ben-linux@fluff.org>
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@ -298,7 +298,7 @@ config I2C_BLACKFIN_TWI
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config I2C_BLACKFIN_TWI_CLK_KHZ
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int "Blackfin TWI I2C clock (kHz)"
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depends on I2C_BLACKFIN_TWI
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range 10 400
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range 21 400
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default 50
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help
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The unit of the TWI clock is kHz.
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@ -614,6 +614,7 @@ static int i2c_bfin_twi_probe(struct platform_device *pdev)
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struct i2c_adapter *p_adap;
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struct resource *res;
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int rc;
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unsigned int clkhilow;
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iface = kzalloc(sizeof(struct bfin_twi_iface), GFP_KERNEL);
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if (!iface) {
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@ -675,10 +676,14 @@ static int i2c_bfin_twi_probe(struct platform_device *pdev)
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/* Set TWI internal clock as 10MHz */
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write_CONTROL(iface, ((get_sclk() / 1024 / 1024 + 5) / 10) & 0x7F);
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/*
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* We will not end up with a CLKDIV=0 because no one will specify
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* 20kHz SCL or less in Kconfig now. (5 * 1024 / 20 = 0x100)
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*/
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clkhilow = 5 * 1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ;
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/* Set Twi interface clock as specified */
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write_CLKDIV(iface, ((5*1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ)
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<< 8) | ((5*1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ)
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& 0xFF));
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write_CLKDIV(iface, (clkhilow << 8) | clkhilow);
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/* Enable TWI */
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write_CONTROL(iface, read_CONTROL(iface) | TWI_ENA);
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