Hi David, Thanks, Vaibhav Hiremath > -----Original Message----- > From: David Brownell [mailto:david-b@xxxxxxxxxxx] > Sent: Saturday, November 29, 2008 1:24 AM > To: Hiremath, Vaibhav > Cc: video4linux-list@xxxxxxxxxx; davinci-linux-open-source- > bounces@xxxxxxxxxxxxxxxxxxxx; linux-omap@xxxxxxxxxxxxxxx; Jadav, > Brijesh R; Shah, Hardik; Hadli, Manjunath; R, Sivaraj; Karicheri, > Muralidharan > Subject: Re: [PATCH 2/2] TVP514x Driver with Review comments fixed > > On Friday 28 November 2008, David Brownell wrote: > > On Friday 28 November 2008, Hiremath, Vaibhav wrote: > > > Will have to now think how to differentiate between these > > > two chips and handle this sequence. > > > > That's really easy, the "id" parameter to probe() tells you: > > > > if (strcmp(id->name, "tvp5146") == 0) > > /* original '46 part ... */; > > else if (strmcp(id->name, "tvp5146m2") == 0) > > /* new '46m2 version ... */ > > ... etc > > ... although it's even easier to use id->driver_data to > hold, for example, a bitmask telling various attributes > of that particular device. Examples here: > > - does it have the extra '46 registers? > - does it use the original '46 init sequence? > - or the new m2 one? > - or the original '47 init sequence? > - or the new m1 version? > - ... > > Another common use of driver_data is to hold a pointer > to a struct holding chip-specific data that doesn't fit > into a simple bitmask. > [Hiremath, Vaibhav] I am trying to use/save complete init sequence in id->driver_data - static const struct i2c_device_id tvp514x_id[] = { {"tvp5146", (unsigned int)&tvp5146_init}, {"tvp5146m2", (unsigned int)&tvp514xm_init}, {"tvp5147", (unsigned int)&tvp5147_init}, {"tvp5147m1", (unsigned int)&tvp514xm_init}, {}, }; NOTE: Please note that init sequence for 46, 47 are different. But I came to know that, client structure doesn't have any parameter which will provide me the index under this id table. The only differentiating parameter we have is "name" (decoder->client->driver->name). I can use "id->driver_data" only in my probe function without any index. So left with only following options - 1) if (strcmp(id->name, "tvp5146") == 0) /* original 46 init seq */; else if (strcmp(id->name, "tvp5147") == 0) /* original 47 init seq */ else if ((strmcp(id->name, "tvp5146m2") == 0) || (strmcp(id->name, "tvp5147m1") == 0)) /* New 46/47 init seq */ 2) Driver specific structure must contain either of - Index of i2c_device_id table, use this to get the driver_data. (This also requires string compare to get the index.) - Pointer to init_reg_seq, which is pointer to array of structure for tvp514x_regs. This is little bit ugly, since will have to export tvp514x_regs structure. - Or have pointer to i2c_device_id itself. (Implemented and tested) I prefer to use second option, instead of comparing the name string in s_power every time. And it will be very easy to add even more chips providing generic solution; we need to just add entry to i2c_device_id with expected init sequence and you are done. Any suggestions or inputs appreciated??? > - Dave -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
